Products: Carburetion

Forget what you thought you knew about the best carbs for vintage cars.

Our Mikuni Carb Kits have changed Everything!!

We still use DCOE Webers for vintage and historic racing, but any car that came with SU or Z. Stromberg carbs will show significant improvements in all aspects of performance by simply changing to the Mikuni HSR carbs. 

" yee gods what a difference ...to say it goes better would be something of an understatement."  that's the comment from a customer in Scotland who recently installed our dual Mikuni carb kit to replace SU carbs on a Volvo Amazon.  And from a US TR6 customer, " Just finished the install on the mikuni’s and damn, what a difference.  This car runs like it just grew another cylinder. " And after a recent installation by a UK TR3 owner - "The car runs like a dream , it accelerates like a scolded cat and has bags of low end torque ..."

See the new photos and more customer comments at the end of the Mikuni Carb Section below and the photo article on installing the Dual Kit in an MGB. http://www.v-performance.com/articles/mgb_-_dual_mikuni_installation_.html

In 2003 we needed improvements to the typical SU and Weber carb setups for use on our Volvo performance and supercharged engines. The result was a year of searching and testing that lead to the conclusion that the Mikuni HSR carbs were clearly the best option. 

During that year of testing numerous carbs were evaluated both on the street and the dyno.  The carbs tested included various versions and sizes of the traditional SU, ZS, Weber sidedraft, Weber downdraft, and a few less commonly used carbs like the Weber 45 MCHH which was offered as an SU replacement. The testing included both stock and modified versions of the carbs.  Test criteria included cost, power, throttle response, fuel economy, ease of installation and tuning. After over a year of work,  the carb that came out best in all categories  for a wide variety of applications was clearly the Mikuni HSR series of carbs.  Other carbs still have their place - where an original equipment look is required for shows or to meet competiton rules.  But for street driving with a stock or modified engine, or racing where the rules allow a modern replacement carb, these are the carbs to use - especially if your car was originally equiped with one or more of the SU or Zenith Stromberg carbs the HSR Mikunis were specifically designed to replace.

Over the winter of 2010/11 we did a comparison of our Quad 45mm Mikuni HSR carbs vs sidedraft Webers. After running the Mikunis on one of our 2.5 L B20 engines, we installed the 45 DCOE carbs that are usually on my racecar.  After finding the engine significantly down on power compared to dyno runs with the Mikunis, we stepped up to a pair of Weber 50 DCO race carbs, first with 42 mm chokes and then with 46 mm chokes. Even with the 46 mm chokes, the power output was lower than with the Mikunis, with higher brake specific fuel consumption, while loosing power at lower rpm. The result - the Mikunis were the clear winner.

Quad 45 Mikunis on the left vs Weber 50 DCO race carbs on a 2.5 L Volvo B20.  The Mikunis were the clear winner in power, throttle response and fuel economy. While doing the testing, we developed a new emulsion tube system for the Mikunis.                                                                               

In 2012 we dyno tested a stock MGB with SU carbs. We then removed the SUs, and installed a pair of 42 mm HSR Mikunis.  With no other changes to the MGB, we were surprised to get a 20% increase in power,  along with a degree of increased throttle reponse that had to be felt to be believed. Overall it completely transformed the driving experience.

The chassis dyno charts below show the comparison between the stock MGB with SU carbs and the same car with our Mikuni HSR carbs. The horsepower scale is on the left, recorded as corrected horsepower at the wheels. Vehicle speed is on the bottom. The tests were conducted in 4th gear. 50 mph is 3000 rpm. The red line is corrected wheel horsepower of the stock MGB with stock SU carbs. 

After testing with the stock setup, we installed our Dual Mikuni Carb Kit with 42 mm HSR carbs. The black spacers, heat shield openings, and intake manifold openings were slightly enlarged to match the size of the 42 mm carbs, tapering from larger to smaller toward the engine. No other changes to the carb or engine were made. We were surprised by an increase of 13 HP, approx 22 %. What can't be shown is how much more fun to drive the car was, with instant throttle response that kicked the car forward when you hit the gas.  Note that there is no loss of low end power.

The dyno chart below shows the same comparison as above with another test added. On this chart the green line is the stock engine with stock SU carbs. The red line is the same stock engine with dual Mikuni 42mm HSR carbs. The top blue line is from another test session. This was a dyno test , on the same chassis dyno under similar conditions, of a 1979 MGB with modified engine, header and high flow exhaust, ported head and "fast road cam", along with the same 42 mm Mikuni HSR carbs, showing the true potential of this setup. All figures are in corrected horsepower at the wheels.

Mikuni HSR Series Carbs

MGB, Sunbeam Alpine,Triumph TR6, and Lotus Elan Mikuni installations are shown in the photos above, as a few examples of the many types of different installations. More photos of MGB, TR6 and other installations can be found below and in the Tech Articles in the "More Info" section of this website. Lotus Elans and Europas and Corvair turbos are so far some of the most popular conversions in 2022, followed by a number of Datsun 240Z orders. A specific kit for the Corvair turbo is new this year.

After 20 years of testing and use, and hundreds of kits sold and installed in various cars all over the world, our Mikuni HSR carb kits have been a great success - proven with each installation to be superior in power, throttle response, fuel economy and reliability. Designed to replace SU and ZS carbs they are a simple replacement for those carbs and are one of the few easily bolted on upgrades that produce a signficant, surprising and easily documented, increase in performance with no other modifications.

Our customers praise and recommend them. A 2015 comment from Scotland after a Volvo installation perhaps says it best: " yee gods what a difference ...to say it goes better would be something of an understatement."  (see the full text of this email and other customer comments on their personal experiences with our Mikuni carb kits at the bottom of this section)

I strongly recommend them for a wide variety of applications including:

1) as a stock replacement or upgrade from SU, Zenith Stromberg, or Weber carbs. 

2) for Volvo 544, 122, 1800, 140 ( and carbed 240s), MGA, MGB, MGC, Triumph TR3, TR4, TR6, TR7, Spitfire, GT6, Datsun 510, 1600, 2000, 240Z, Mini, Jaguar, Lotus, SAAB, Sunbeam Alpine, Austen Healey, TVR, Daimler, Rover, Holden, etc.

3) in one, two, three, four, six or 8 carb applications.

4) for stock, street, modiified, supercharged, turbo, rally and racing engines.

5) shipped around the world including: Australia, New Zealand, South Africa, Canada, Great Britain, South America, Norway, Sweden, Poland, Germany, France, Belgium, The Netherlands, Spain, Finland, etc.

Technologically superior in design to the typical SU, Zenith Stromberg or Weber carbs that were originally designed more than 60 years ago, the Mikuni HSR flat slide is a modern carb, designed specifically as a bolt-on SU or ZS replacement that will do it all - more power, better fuel mileage and easy tuning in one package. These advances are made possible by several innovations, including the use of a flat throttle plate or "Flat Slide" derived fom racing fuel injection systems which allows for increased air flow and produces extremely high manifold vacuum, aiding in fuel atomization while increasing port velocity. 

Above is an SU HIF 44 on the left compared to a Mikuni 45 HSR on the right. Note the size of the Mikuni's unabstructed flow area- the key to its higher flow capacity.  The Mikuni is 45 mm all the way through without a smaller venturi area or throttle plate to restrict air flow.

Compared to SU carbs, a similarly sized Mikuni HSR will flow 30 - 40% more air. They will provide better throttle response, support more power - especially at higher rpms, and will equal or exceed the SU in fuel economy.  In road and dyno testing dual Mikunis have equaled or exceeded Weber sidedrafts in power while getting 50% better fuel mileage - at less than 2/3 the cost, using the stock SU or ZS intake manifold. Customers are amazed by the degree of performance improvement as well as the ease of installation and tuning. If you are interested in improving your vintgage car's performance, including its reliability, there is no reason to stick with obsolete, leaky, hard to tune SU or ZS carbs or having to chose between a sidedraft Weber for power or a downdraft Weber for economy. The solution is an upgrade to the Mikuni HSR carbs.

All carbs in these kits have been modified for automotive use. Since the original SU and ZS carbs that they are replacing are the same, regardless of the car make, the same basic kits can be used for installations on a variety of different cars with some changes in jetting and throttle linkage.

Prices include the cost of parts and labor needed for the modifications and manifold adapters.  Prices are finally going up after several years of relatively stable costs. Air filters reflect the biggest changes with many of the filters that we have been using having been discontinued - so we are now offering a new range of filter options. Email for new filter details. Price increases are affective June 1, 2022 though all changes may not yet have been made below. 

Price summary:

 Single Carb Kits:

• Single 42 or 45 mm Carb Kit, modified for automotive use, with smaller 2.3 float needle and seat and larger main jet installed, for cable throttle with manifold adapter, without an air filter - $395 
• Single 42 or 45 mm Carb Kit - Modified for Supercharger Applications - for cable throttle , without an air filter - $475
• Add $75 for a carb modified with extended throttle shaft for lever type throttle linkage
• Add air filter options.

Dual Carb Kits:

Replaces 2 SU or Zenith Stromberg carbs on a 4 or 6 cylinder motor  - $995 without air filters. Add air filter options including adapter collars which may allow for the use of stock air filters or air boxes.

Weber DCOE Sidedraft Replacement -  two HSR carbs mounted as one dual barrel carb -$1095 without air filters.

Triple Carb Kits:

Replaces 3  SU or ZS Carbs on a 6 cylinder motor - $1495 without air filters.  Add air filter options including adapter collars which may allow for the use of stock air filters or air boxes.

Quad Carb Kits:  

Four  carbs modified to mount in pairs on weber sidedraft type manifolds - includes manifold mounts and linkage adapters  $2195

 Six Carb Kits:

Six Carbs modified to mount in pairs on Weber sidedraft type manifolds - with manifold mounts and linkage adapters  - $ 3330

Air Filter Options;

These include the traditional K& N air filters shown in most of our installed carb photos. However most of these filters have been discontinued by K & N, and the prices on some of those that are still available have gone up considerably. Our new standard filter for most applications is also from K & N, under the Spectre brand name. Filtration and air flow specifications are equal to or better than the previously used filters. They require a modification to the filters for use with our custom made adpater collars - sold as a set with the modified filters and collars -  Email for photos and details. For most applications $75 each with adapter collars - add $7.50 for each vent line fitting needed.

MORE DETAILS

See a more detailed description of the Mikuni HSR Carbs, each kit, and installation and tuning parts below:

Originally designed and marketed as a performance replacement  for SU carbs on Harley Davidson motorcycles, the size of the 45 mm Mikuni, the same as the nominal 1 3/4 inch size of an HS6 SU ( though the venturi is actually much larger ), and incorporation of an accelerator pump jet, makes it perfect for automotive applications. Carburetor development for automobiles stagnated more than 30 years ago when automotive manufacturers turned to fuel injection to meet emissions and fuel economy requirements, while at the same time, the evolution of carburetor design for motorcycles, snowmobiles and jet skis continued at a rapid pace.  The Mikuni flat slide is the most advanced product of those years of continuing development which began with the traditional SU carb of the 1950s.The result is a carburetor that is superior both in power and fuel economy as well as being reliable and easy to tune and maintain. Parts are less expensive and fewer in number than in most automotive style carburetors.

For a flow rate comparison, measured at a pressure difference of 12 inches of water, Mikuni rates the carb flow as follows:
Mikuni HSR42: 213 CFM
Mikuni HSR45: 237 CFM
Mikuni HSR48: 270 CFM

Our Mikuni carb kits are designed to make the Mikunis an easy, bolt-on replacement for SU or ZS carbs, right on the stock SU or ZS manifold. They will fit in the same space as the original carbs, are 6.75" from top to bottom, 3.5 " tall from the center of the carb opening, and are approximately the same length front to back with manifold adpater as an HS6 SU - 4.1". To determine clearance with the 3" element K &N air filter, the measurement is 7.5 " from the manifold mount surface to the outer end of the filter, 6.5" with a 2" filter. With our new Spectre Filter setup the measurement is 8" from the manifold mounting face. In most applications they will attach directly to the stock linkage pieces provided.   The dual kit includes two carbs, two carb to manifold adapters, a throttle shaft, linkage to adapt to the SU or ZS linkage, with the option of adding air filters. Similar kits are available for single and triple carb applications. As with any carb swap, expect to do some tuning to match these carbs to your engine and get maximum performance and fuel economy. Tuning recommendations and jet kits are available.                                                                                                                                                                                                                                                    

In the Mikuni specific jets meter fuel for various throttle openings. Compared to a sidedraft weber, tuning is much simpler, cheaper and more direct since there are no emulsion tubes, replaceable venturies or the need to guess as to what the result of a change will be. It is hard to describe how much of a pleasure tuning these carbs can be, as compared to SUs or Webers. You really have to experience it to fully comprehend the difference.

For additional details on these carbs, a complete tuning and parts manual is available online from Mikuni. Go to www.mikuni.com/fs-manuals.html and click on "HSR tuning manual."  Tuning videos for the carbs as used on motorcycles can be found on Youtube.

Our installation and Tuning Instructions are in the "More Info / Tech Articles" section of this Website.            Take a look at it even if you are just considering a purchase as it has much more detail on the carbs and their installation.  There is also a photo spread detailing the installation on an MGB and another underway on the TR6 dual carb installation.

All of our carbs sold for automotive use are modified to accommodate the higher fuel pressures of automotive fuel systems as compared to the gravity feed systems used in motorcycles. They have also had the main jets that come with the carbs replaced with main jets more suited to the individual application. In multi-carb kits the stock throttle shafts have been replaced with longer, custom made throttle shafts which allow the shafts to be connected and the carbs easily synchronized. These modifications are built into the price of each kit.  Additional jets to fine tune the carbs to your application are extra. See the recommended jet tuning kits which allow us to custom jet your carbs and include sets of jets richer and leaner than those installed. Add $25 per carb to the below prices for 48 mm carbs.

Order note - The carbs for the kits listed below are modified on a custom basis per application based on information that you give us about your car, engine. linkage, etc. This means that there is usually a delay between the time of order and date of shipping that could range from a couple of days to a couple of weeks depending on the degree of modification needed for the particular kit ordered, availability of the specific carbs and air filters ordered and the parts required to modify the carbs to match your application. Please ask about estimated shipping time before or at the time that you place your order.

Detailed Carb KIt Descriptions:

The Dual Mikuni Kit

Our most popular kit. The Dual Kit for SU or ZS type manifolds consists of 2  HSR 42mm or 45mm carbs modified with extended throttle shafts, smaller float bowl needle and seat, and larger main jets. The kit includes manifold adapters and linkage designed to connect to the stock rod or cable type throttle linkage- $ 995.  Add $ 50 to the above prices for the kit with HSR 48 mm carbs.  Several sizes and types of air filters are available. Email for air filter details.

The included manifold adapters allow the carbs to fit on any manifold designed for similarly sized SU or Zenith Stromberg carbs. Minor differences in linkage are usually easy to adapt. Since it is replacing the same carbs whether on a Volvo, MG, Triumph, etc., the kit is the same for each of these applications except for differences in jetting.

Choke cables and/or choke cable adapters are not included as the car's original choke cables can often be used with minor modifications. We have a selection of cable extenders, spitters and choke cable bracket systems in the parts section below. Most commonly used is the choke bracket system, usually for cars with the carbs on the right hand side - used with your original choke cable.

The Dual Kit includes one pair of larger main jets installed.  Extra main jets - $ 8.00 a pair - are recommended . Smaller pilot jets and larger needle jets are also often needed depending on the applications. A tuning kit with jets selected for each application is recommended, which allows us to jet the carbs for your application and include a selection of richer and leanger jets for fine tuning. See our tuning kits in the parts section below for details.

Other parts frequently ordered along with the kit above include:  Volvo SU aluminum intake manifold.  Used, uncoated bead blasted $ 125.00.New manifolds also available ( $125 ) but the casting is not as good as the originals. Extra main jets $ 8.00 per pair. Needle jets $14 each.  Jet Tuning Kit recommended - $32 or $60 with one pair of richer needled jets for the 42mm carbs or $88 for the 45mm carbs with 2 pairs needled jets included. Accelerator pump jets $12 per pair.  Short idle adjust screws - $16.50 each.

Conversion from single carb to dual carbs -  If you have a Volvo, MGB, Triumph Spitfire or other car model that came in both single and dual carb configurations we may be able to help you convert to two carbs ( with significant performance increases ) by providing a dual carb manifold.  Email for details.

Dual Mikuni - Single Weber DCOE Replacement Kit

This kit is essentially half of the Quad Kit described below. Two Mikuni HSR carbs are modified and ganged together to replace a single Weber Sidedraft carb on a single carb manifold.  $1095 without air filters. Weber style filters can be used with adapters.

The Mikuni Triple Kit

Similar to the dual kit, but designed to replace SU or ZS carbs on a six cylinder engine. The kit consists of  3  HSR 42mm or 45mm  carbs modified with extended throttle shafts, smaller float bowl needle and seat, and larger main jets. Includes manifold adapters and linkage designed to connect to the stock throttle linkage. Aftermarket manifolds, not included in the kit, allow two carb setups like the Triumph TR6 to be converted to 3 carbs.  $ 1495 for the kit without air filters.  Several sizes and types of air filters are available. Email for air filter details. Add $420 for polished carbs.

The Mikuni Single Mount Kit

The Mikuni Single Mount Kit is a perfect replacement for cars with a single SU or Zenith Stromberg carb. Available with a choice of  HSR 42mm, 45mm or 48 mm carb, the basic kit includes one carb modified with a smaller needle and seat for higher fuel pressure, larger main jets, with a mounting flange adapter to adapt to your manifold. A throttle cable mounting bracket is also included. Throttle and choke cables are not included but can be provided on a custom basis.

• Single 42 or 45 mm Carb Kit, modified for automotive use, for cable throttle with manifold adapter, without an air filter - $395 
• Single 42 or 45 mm SC Carb Kit for supercharger applications - for cable throttle with modified float bowl, accelerator pump and jetting modifications to meet the demands of supercharged operation, with manifold adapter, without an air filter - $475
• Add $25 to change either of the above to a 48 mm carb
• Add $75 for a carb modified with extended throttle shaft for lever type throttle linkage
• Add $65  for standard chrome or black top K& N  air filter
• New for 2022 - a dedicated kit for the Corvair Turbo with modified 45mm carb and adapters for both the B and F turbos. $595

For a more formal look, polished versions of each carb are available. To substitute polished carbs in any of the kits, add $140 to the listed price for each polished carb added.

 Single Mikuni HSR on a Mini

 Single Mikuni on an MG Midget

Mikuni SC Carb Kit on a Mini with Toyota Supercharger

Our Single Mikuni SC Kit on a Moss Motors Supercharger in an MGB

Upgrade your Supercharger Kit with a Mikuni. The photos above and to the right show one of our modified HSR 45 Mikuni carbs replacing the SU carb that originally came on this Moss Motors MGB supercharger kit. When we first saw the Moss kit we questioned why they would take a modern supercharger and put an ancient carb on it.  We later found out that Moss had in fact experimented with using a stock Mikuni HSR carb, but had experienced problems with hesitation that they could not solve.  Since we had learned how to eliminate this problem as part of the testing and development process with the Mikuni HSR Carb on our Volvo supercharger systems, we knew how to make it work on the MG. The big change is that the carb float bowl has been modified to increase the capacity of the accelerator pump by approximately 50%. With this modification and proper tuning we can provide a Mikuni carb that is a tremendous upgrade for the Moss Motors kit or any other supercharger kit or turbo application that uses an SU or ZS carb.  The basic kit includes the carb with our standard modifications for automotive applications, with a modified float bowl and larger accelerator pump added, with a larger main jet, and a mounting adapter that allows it to be bolted on in place of an SU or ZS carb - $ 475.  Air filters ( $60 - $80 for most styles ), additional jets and other parts can also be supplied.  The SC jet tuning kit ( $58 ), listed under Mikuni Parts  ( below ), is highly recommended for tuning and will allow us to jet the carb for your application before shipping.

New for 2022 - a Mikuni kit for the Corvair Turbo including a modified 45mm carb with adapters for both the B and F turbos. $595. Email for photos and details.

The Quad Mikuni Kit --  The Ultimate Performance Carb Kit  -

(6 carb version also available)

A unique and totally cool setup! 4 HSR Mikuni carbs, modified to mount in pairs on  Weber DCOE or DCO  type manifolds, using similar linkage, for large displacement and high HP racing and street 4 cyl. engines. It will easily outflow and produce more power than Weber carbs of similar sizes due to the much cleaner air flow path and better fuel atomization. Comparison dyno testing has shown that a set of 45 Mikunis will easily out perform a set of 50 DCO Webers with higher HP and torque from low to high RPM, while using less fuel. These sets are produced in our shop on a custom basis so allow time for machining and assembly.  For air filters see the ITG filters in the filter section below.

• Four  carbs modified to mount in pairs on weber sidedraft type manifolds - includes manifold mounts and linkage adapters  $2195
• Four carbs modified to mount in pairs on weber sidedraft type manifolds - includes manifolds, manifold mounts  & linkage adapters, for Volvo B20/21/23/230 including a Weber DCOE style intake manifold, and air filter adapters  - $2675 --  Several type of air filters available. Call or email to confirm prices for each application.
• Email for kit prices which include manifolds and air filters for non - Volvo applications
• Six Carbs modified to mount in pairs on Weber sidedraft type manifolds - with manifold mounts and linkage adapters  - $ 3330   Email for details.

choke cable splitter with choke cable and end cables

Closeup  showing the choke cable attachment in the splitter

Throttle shafts -  $49.50 each, two needed.

Couplers -  $22.5 each, two needed

Connecting shaft  - $12.50  one needed

Lever arm $13.50 and ball stud or cable adapter -  $7.50 one needed

Carb to manifold adapters for 42, 45, and 48 mm carbs - $30 - two needed

Float Bowl 2.3 Needle and Seat sets - $ 28.00 each  - two needed to replace stock 4.0 size used for gravity feed applications

Total on parts needed to convert and adapt two carbs: $ $293.50

Changes in jetting will also be needed in most applications.  See jets and jet kit pricing above.

 

For advanced tuning:

For race application and emulsion tube conversion kit - Adds an air jet and modified needle jet to create an emulsion tube system - another Vintage Performance innovation $29.50 per carb.  Email for details.

 

                                           Dual Mikuni Kit on a Morgan

See an article on the Morgan Mikuni installation here:	https://www.gomog.com/allmorgan/MikuniConversion.html

 

 

Triple Mikuni Kit on a Holden

The Dual Mikuni Kit in a Datsun 510

Datsun 1600 Installation

 

Several MGB Installations are Pictured Below.

See the more detailed series of MGB installation photos and comments in our Tech Articles Section found through the "More Info" tab at the top of the page. Note that the HS4 SU carb is a 1.5" or 38mm carb. We replace them with 42m Mikunis ( 1.65" ).  This requires that the intake manifold opening, and/or spacer be enlarged slightly to match the larger carb size and considerably improves the air flow into the manifold. The result is an increase in power throughout the normal rev range including at low rpms.

MGBGT	Aluminum Cross Flow Head with 45mm Mikunis

 TR4 Installations

 Triumph GT6

Triumph TR6

Our TR6 system shown in the photos above uses the stock throttle linkage and choke cables with small modifications to both.

 Triumph Spitfire - Vintage Racecar

 See the story on this car and the Mikunis at: http://www.britishracecar.com/RichardBrown-Triumph-Spitfire.htm

                       And now a photo of a Jag E type installation

See the comments on this installation in the comments section below - 8/21 - James Woolbright

Installations on cars not listed as having documented Mikuni HSR Carb installations.

Comments on MIkuni Carb Installations

1/30/2024 9:29 AM, Adrian Bowles wrote:  ( Single Mikuni carb installation on an MG Midget )

Hi John

I finally had a chance to drive my 76 Midget with your Mikuni HSR42 conversion kit and all I can say is wow! What a difference. My butt-dyno may not be calibrated but the difference over the Stromberg is amazing. Smooth power delivery - and plenty of it - at all RPMs. I couldn’t stop smiling. Thanks for offering this kit - I plan to install one in my project Midget later this year. 

11/21/2023 12:50 PM, Paul Hunter wrote:
>
> Dear John--
Your calls on the jetting and adjustments for my 142 were right on. Runs beautifully, with no hitches or hesitations from idle to wide open throttle. I haven't driven far enough to get the mileage yet, but will see. Turning the two idle jets together at the same time needs to be in your instructions, which proved to be a crucial tip. Thank you, thank you.
>
 And have a happy Thanksgiving there.
 

On 10/5/2023 8:53 PM, Keith Simon wrote:
> Carbs are wonderful, have enjoyed the install.
> Best,
> Keith

On 8/1/2023 3:54 PM, Senga wrote:
> Hello Mr. Parker.  The Mikunis and kit I got from you for the 1964 Volvo 544 sport worked wonderful.  I would like to order a complete manual choke set up with cables and whatever else is required.  It still has the factory splitter located under the dash.
> Also one more quick question.  Do you know of a “reliable” mechanical fuel pump.  We are on our 3rd one so far and they don’t leak but just don’t seem to last.
> Thank you for your time.
> Ty
 

On 3/19/2023 10:57 AM, Cameron Pitcairn wrote:  ( from the UK about his GT6 ) 

On 2/24/2023 1:45 PM, Samuel Arant wrote:

On 8/27/2022 8:35 PM, Greg Schnittger wrote:

John,

Dec 20, 2020 at 2:08 PM
Subject: mikuni
To: John Parker <jparker3@twcny.rr.com>


Hello John,  just wanted to say i'm very pleased with the mikunis on my volvo 1800.  They've got the old thing purring like a kitten and they have definitely boosted hp.  I wanted to see if i could buy another choke cable from you if you have one available.  I managed to bugger up the longer one in the fan belt before i secured it properly.  Let me know.

          Jeff

John, I installed the carbs you sent with no issues. They fired up immediately with some choke. I increased the idle adjusters from zero to one half turn and the car idles well and runs like a bandit.. These carbs are terrific! I plan to check the  mixture with an air /fuel meter but all seems good for the moment.

 

Best Regards,

Brian McCauley

 

On 9/24/2020 8:34 AM, Brookhouse Volvo Parts wrote:

Quite a few years ago I purchased for you a pair of Mikuni twin carbs for my 1967 Volvo 122S. They have been awesome, but now I need to get a new pair of K&N air filters for them. Can you tell me which K&N air filters you use?

 Regards

Simon Richardson

Brookhouse Volvo Parts.

On 8/18/2020 8:15 PM, Brian McCleery wrote: ( TR6 with dual Mikuni 42's )

Running like a top with the points! Might need to shorten the threaded rod about 0.25” to allow the carbs to relax to idle better but awesome!  Not a single one.( jet change ). I trusted that you knew your stuff and was not disappointed. 

 On 6/14/2020 1:07 PM, James Walton wrote:

Finally installed my MGB Mikuni kit last week (photo attached). Really nice improvement..

Most of those British carbs are ported and British Vac argues it is the best way to go. The Zenith Stromberg s are ported. The Hitachi SU's I had were ported. My 76 originally had a vac retard and British Vac came up with a vac advance for it. This is what I was using.
 

All that aside I want to thank you for the carb's and the set-up. I have had to do very little except raise the main jet one notch. The pilot screw s just needed a quarter turn and adjust idle.
 

My car was running like crap before so these carbs on my modified engine were the answer without blowing another season of playing what is the best needle with the Hitachi SU's. Paltech who sold me them assured they had the right needle for my engine, etc, etc. I am really glad I spent the money and tried completely different carbs.

I had a comment from a couple very long time TR6 owners and found my car the most impressive one they have driven in.

So again thank you for your expertise in setting these carbs up. Vac discussions aside I am, really, really grateful. I will send you some under hood pics once I get my air box adapted.

The car before would never easily start but with the Mikuni's it was first crank. I couldn't believe it!   Thanks😊

5/29/2020 5:15 PM, Dave Luukkonen wrote: ( regarding a dual kit on a '73 MGB )

I finally got to drive the MG with the new Mikuni carbs on it today. I didn’t get enough of a drive taking it just from the garage to the upholstery shop but wow the carbs really seem to work well! I’m gonna have to send you a picture of the choke cable though. I’m not sure I got that right because it doesn’t lock into the receptacle the way I thought it should. It still works great, so it’s not a big deal.
I’ll send pictures and maybe a video later; I think the Mikuni‘s are going to be outstanding!
Dave luukkonen

On 5/27/2020 3:02 PM, David Fallon wrote: 

As for the TR-7 is was an EASY install for the carbs. The only thing is I had to go one size larger on the jets. Throttle response is ten times better than the SU’S I had on it when replacing the Stromberg’s. Also get between 22-26 MPG if I keep my foot out of it. I did go with an MSD ign. and headers. The car is still put away from winter however I will get photos on install to you.

I have a TR-6 and a GT-6 also working on. Love this setup!

Dave

 5/20/2020 7:17 PM, Paul Slabiak wrote ( regarding a dual Mikuni carb conversion on a 1979 Triumph Spitfire ):
Thanks again, I REALLY LOVE this conversion, and fully intend to order more in the future, as we do a fair amount of webber conversions. (I do not like the webbers).

Paul Slabiak, Project Manager

Classic Auto LEDs & BMC British Automobile, LLC

 On 6/5/2019 10:56 AM, Jim Hess wrote regarding his Triple carb TR6 installation ) to tell me that:

I just updated my blog with the Mikuni information.
www.trippstr6.blogspot.com

(There is series of good installation photos there.)

On 6/1/2019 9:00 AM, Larry Berg wrote: ( regarding a Triple carb TR6 installation )

The last install on Gary Stephensons TR6 went quite well and he is very happy. 

His first words after pulling out of the drive and onto the street were “This thing could be dangerous”.

 Larry Berg

Hi John,
Time to send that endorsement letter, now that I have spent some time with the Mikuni set-up.
Enclosing letter and some pix.
You also asked me to remind you to refund me for the Choke kit that I didn’t need. 

Thanks again for your help, I am very happy with the change.

Letter:

To Lotus twin-cam owners thinking about replacing Stromberg carbs; 
John has made a great update for  your Twincam with a Stromberg head. The Mikuni conversion requires no modifications to the engine; just swap out the carbs, hook up to existing throttle and choke cables, some basic tuning, and you will see a real improvement in drivability and performance.
If you are looking to replace the Stromberg carbs, this is a fantastic alternative to an expensive Weber-head conversion.  I have had my Europa for 45 years, and rebuilt the carbs twice, before deciding to try the Mikunis. I have driven Lotus Twincams with Stromberg and Weber heads, and the Mikuni-Stromberg combination feels somewhere in between, for a reasonable price.
The Mikunis are a real improvement, and the work John has done preparing the carbs makes for an easy installation.
Thank you John.

Robert Schefman
1974 Lotus Europa Special

On 8/4/2018 5:56 PM,  Andy Pitman wrote from the UK:

Hi.  It’s been a long time past since you sent me the Mikuni carbs for my triumph tr3a, The restoration of the car is know complete and the car is now on the road.  As promised I can now let you know how I got on,  fitting the carbs was very easy and they really look the part, As you said the engine should start and run without any alterations to settings and that is exactly what happened even to the point that I have only adjusted the tick over and that’s all I’ve had to do. The car runs like a dream , it accelerates like a scolded cat and has bags of low end torque which surprises me as I have fitted a fast road cam and usually you would have to get the revs up to start to feel any power.

If you ever need someone to recommend you  and your product please feel free to contact me.

Yours faithfully. Andy Pitman.

John, I finally solved my niggling miss problem, it was an intermittent leak of the vacuum advance.  It was a misinformed casting.  

The car is running beautifully, much more power.  We skipped spring weather this year so I plan to do the final Dyno in the fall.  Too hot and humid in the Missouri Ozarks for a summer test.  The choke system you had made is a thing of beauty, makes the car much more drivable. Thanks, Fred

3/22/2018 11:45 AM, Ron Camillone wrote: >( regarding his 1979 MGB ) > >> Hi John, > Just wanted to say thanks again for the Mikuni, the car runs better than it ever has, and just wanted to send  a pick of the single carb MG so that if anyone ever orders > you can see they will need the smaller K&N. > I appreciate you crediting back for the larger one. > > Have a great day and thanks again. > > Ron 5/21/20 update: We never had to change the jets, it worked perfect the way you shipped it. Still running great.   Ron

2/3/2018 2:27 AM, Stephen Wood wrote:  ( from New Zealand )

Hi John
The conversion is now all complete and the MGB is going very well.
 Early December we did a 4 day trip to Northlands and all went well.
The fuel economy worked out at 10lL per 100Km over the long trip, pretty happy with that.

I followed nearly all of the installation instructions and it all went well.
Once we got the timing correct tuning was really easy.
I’ve done about 2000km  since and it’s been a total joy to drive every km.

There was quite a lot of interest in the Auckland MG car club with comments like Why!! and where can I get a pair.
http://www.mgclub.org.nz/tools/gallery/photos.aspx?SECT=Far-North-2017

Regards,
Stephen Wood

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5/22/2017 1:41 PM, Fred Ford wrote about his triple 42 Mikuni on a TR6 ( we had been emailing back and forth about a midrange rpm miss and whether it was related to carb tuning or igniition):

Success! You were right, it was ignition, new coil and reset of the dwell and the miss is gone.  I couldn’t be happier with the carbs and set up. I will let you know the final dyno numbers.  

I do want a choke bracket and set up for my triple Mikuni set up.  I will call with payment.  Thanks.  f

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Carbs installed. Runs great much better response then the SU carbs.

Air cleaner took some modifications . 

Thanks for getting them to me so fast. 

Jerry Derrick

 

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4/9/2017 2:20 PM,Tom Butkovich wrote about his recent TR6 dual Mikuni installation:

John,

 Just finished the install on the mikuni’s and damn, what a difference.  This car runs like it just grew another cylinder.

 You had these things dialed in near perfect and the plugs are beautiful.  Just some minor tweaking and I’m home.  Thanks again for your help.

 Tom

And on 4/13 Tom wrote:

All good on my end with the choke setup, just modified some cables and used a splitter and adjusters.  I attached a few pics.

 All works fine and the instant throttle response I get with these carbs is awesome.  Looking forward to the distributor and I’ll let you know how she works out.

Thanks again.  Tom

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A followup on the Jag E -type installation from 2014 shown in the photo above.

2/19/2017 10:16 AM, James Woolbright wrote:

James 

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Hi John,

Andy Thomlinson

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On 4/20/2016 4:05 PM, Dan Borg (TCI) wrote about his 1800 Mikuni installation:

Hi John,

 Love the Mikuni’s on the car!!!

Regards,   Daniel C. Borg

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On 4/12/2016 11:13 PM, Jonny Wonderland wrote:

The carbs absolutely transformed the MGB.

Even did a bit of a video on installing them.

https://www.youtube.com/watch?v=30bXQr4oGmI

Cheers!

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Hi John,

Thanks a lot for your e-mail and for asking how the Mikunis are working in the Sunbeam.Everything is top cool, the carbs work now perfectly and I love to hear’em breathing.

 I first had some troubles installing them because my sunbeam had a different (straight) carburetor adaptor than the one you had in the pictures on your website and hence the Mikis did not fit at first. A club friend had a spare curved inlet adaptor ( MK V manifold ) and the rest of the installation was pretty easy as all parts fitted perfectly.

 The car is now much quicker on the throttle, much faster action/reaction and much better acceleration, plus less gasoline consumption over all. All in all, super happy happy happy!

But the best is the sound! The Sunbeam - Guys where interested, but as always there are the originality fanatics and the cool boys who find such improvements great.

 Cheerio & have a great day

Urs & Sidna Umbricht

On   2/24/2016 4:19 PM, Ron Miller wrote regarding his Spitfire 1500 single carb installation:

All in all I think the Mikuni is fantastic and a quantum leap from the Zenith Stromberg .
            Ron

Weber Carbs

Dual side draft DCOE Weber carbs - the classic performance and racing carb for vintage sportscars. Available used  and new, in 40, 42, 45 and 48 mm sizes and can be set up for specific applications and matched to manifolds, porting, cam, etc. Linkage and air filter kits also available. We are not a traditional "dealer" of these carbs and cannot match discount pricing - but with a purchase from us you get advice and help with setup and tuning that can be "pricless". Discount dealers send you the carbs in a box, with the same jetting no matter what the application is, usually with the cheapest manifolds and linkage available,  and let you figure out how to make it work.

These carbs are still the standard for vintage racing, though the Mikunis described above are  now a better choice for street use and racing where a period correct carb is not required.  Production of Weber carbs has been intermittent in the last few years ( as has quality ) but they are now available again, including the newer type 152 - 45 DCOE - $835 a pair , and the classic and hard to find classic Type 9 - 45 DCOE - $935 a pair . Email for current pricing on other sizes.

Intake Manifolds

Manifolds for sidedraft - DCOE type carbs

Available forVolvo  B18, B20, B21, B23, B230 engines. These are copies of the original, no longer available, R- Sport manifold . They should not be confused with the cheap, shorty manifolds usually offered in Weber kits that have flow restrictions due to their short length and comparatively tight bends. In a recent dyno test we gained 12 HP by switching from the commonly sold “shorties” to our longer manifolds.  With the longer manifolds and suitable air filters, the inner fender on certain models - 1800 & 122 - may have to be modified for clearnace. These are the best flowing manifolds available, but usually need some casting cleanup. See installation photos.

Recommended for all installations with Weber DCOE type carbs ( and similar sidedrafts ) and our Quad Mikuni System. Mandatory for racing, rallying and large displacement engines $355 - includes soft mounts. Modified for the type of linkage we prefer as shown in the  photo in the Weber Carb section immediately above - $395

SU intake manifolds

These are the original aluminum intakes used on the early dual SU carbed Volvos and are preferred over the new castings.  Provides a significant improvement over the later cast iron combination intake and exhaust manifolds.  Shown on the left with linkage bracket and our Mikuni carburetor adapters.  These are all used manifolds. Bead blasted and  ceramic coated they look new. Getting hard to find so when stock is low we may have to limit sales of  these to customers who are also purchasing carb kits. The earlier castings do not have the center port as in the photo below, but can be connected through a port at the end of the manifold.

Silver ceramic coated aluminum - $155   - not currently available

Uncoated in used  "as is" condition - $100   Cleaned up to bare casting - $125  ( looks like a new casting and flows better than the new castings)

New aluminum SU type Volvo b18/b20 intake manifolds now available -$125 .  These can be used with our Mikuni Carb Kits when the originals are not available. They come as bare castings, as in the photo below, without linkage brackets and other fittings which are shown in the photos of the original manifolds below. Some cleanup of the ports is usually required to improve flow which is why I prefer the original castings.

Shown below - original SU manifold, ceramic coated and setup for our Mikuni carbs.

And for those who would like to mount dual Mikjuni carbs on a B21, B23, or B230, we have found that the Volvo Penta AQ 140 manifold will work.  Not in stock, but available used if you can find one.

Linkage

Throttle Linkage Lever Arms - Top quality, custom made, machined aluminum throttle linkage arms for Weber sidedraft  and other similar carbs - $ 33 each.  Email or call for prices and availability of other linkage components including custom made, braided stainless steel throttle cables.

Air Horns

Full radius aluminum air horns - in several lengths for Weber DCOE, DCO and similar type carbs. Lengths start at 35 mm and go up from there.  Prices start at  $ 62 for the short ones for 45 DCOE carbs and $78 for the short ones for DCO carbs. Prices go up a small amount for the longer ones.

The air horns shipped with Weber carbs are basically for decoration only. In dyno testing on Volvos we usually get better power with them removed. The full radius horns really work to improve flow and are available in several lengths to help with tuning. On our Volvo engines we usually find that the shorter horns work best as in the photo below.

Below are Mikuni air horns with screen type filters - perfect for race applications  -  $36 for each horn - email for prices and availability of filter screens .

Mikuni air horns with screen filters on Jim Grey's TR4 vintage racer

Filters

ITG Foam Air filters - Imported from England for sidedraft carbs - email for details and pricing.

Available in various sizes, the rounded shape allows them to fit where square filters will not.

Mandatory for use with Weber sidedraft carbs and the longer manifolds on the Volvo 1800.

Accessories

Mikuni HSR jets - main jets - $5.50 per pair. Accelerator pump jets $8 per pair. Re-profiled jet needles $15 per pair.

Soft mounts and spacers for SU and other carbs in performance applications - email for details.

Weber DCOE Jets and Accessories Main jets $6. Air correction jets $6. Idle jets $7. Email for prices on other jets and accessories. 

Used Weber Sidedraft carbs We usually have used Weber DCOE carbs in stock. Email for availability and pricing.

Holley fuel pressure regulator - 1 - 4 PSI -  $36.50