# Bike carbs



## MKIGTITDI (Aug 25, 2007)

*Write up bike carbs on a counterflow*

Im ooking at goinng from CIS to bike carbs and have done a little research on it allready but has anybody done it on this forum? Im looking at going to yamaha yzf/R1 1000 carbs and was wondering what all is involve past making the mani, changing out the fuel pump and tuning?


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## Svedka (Jul 4, 2008)

MKIGTITDI said:


> Im ooking at goinng from CIS to bike carbs and have done a little research on it allready but has anybody done it on this forum? Im looking at going to yamaha yzf/R1 1000 carbs and was wondering what all is involve past making the mani, changing out the fuel pump and tuning?


You will have to fab up a manifold I have seen/heard that the DCOE style manifold can be sourced fairly cheap and making adapters to attach the R1 carbs should be fairly easy. 

pic is on ITB's but would be the same concept



dutch_diy said:


> Ok, tiny update here:
> 
> Found an example of someone that made flanges to press-fit onto the ITB's to make them suitable for ordinary DCOE manifolds, looks like a decent solution...
> 
> ...



for mock up
You will want a counterflow head with a exhaust manifold attached so there is no clearance issues with the exhaust then you can also make heat shields for the bottom of the carbs this should give you a great idea of how much room you will need to clearance in the firewall, use the factory injector holes for a vacume log for your brake booster adapt the throttle linkage and figure out what ignition system to use


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## mk1nutt (Feb 12, 2009)

Done a search? Try this:

http://forums.vwvortex.com/showthread.php?4647341

16v stuff, but still pertinent.

Fabricating the manifold is the hard part. Mine is on a 16v and is very similar to the one on the post above, only real difference was I used thicker plate and used a stick welder to weld it, which caused it to warp slightly so I had it milled at a local machine shop (~$50.) I've been thinking about building a similar set up for one of my 8vs, but plan on making it out of steel, b/c it's cheaper, easier, and it's just an 8v. 

You'll need to re-jet the carbs, but that's simple, just roll to your local yamaha shop and buy some jets. Depending on your set up you'll need different jets, but I would start some where around 1.6mm for an 8v (stock r1 is like 1.3.) 

Then you'll need to figure something out for your throttle cable and choke. I happened to have allot of spare motorbike parts to dig through to find something that would work.

You'll also need to decide what to do for fuel delivery, you need a low pressure pump(~4psi.) I simply used an r1 pump, mounted in the stock location with a factory mk3 aba filter. There are other options, but this is likely the cheapest/simplest.

Then there is ignition. With CIS you can use the stock ignition, but it's far from ideal. I would get the carb set up put together and get it running, then maybe upgrade the ignition. I ended up getting rid of my dizzy doing a megajolt/edis system, this gives the ability to customize my ignition map.

I have found that the proper ignition advance makes all the difference in the world, both with fuel consumption and performance. 

Oh, and air filters, get a set of UNI's and revel at the glorious howl from those carbs.

Hope this helps.


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## MKIGTITDI (Aug 25, 2007)

Thank you both for your advice. Would running my current knock box be suffice for the timing for now? Svedka ive look all through that post for most of my info and i thank you for re-posting it. I was trying to see if maybe anyones done it on a counterflow horizontally placed motor. I sa the guy with the pointer but his is a little different then mine.


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## Svedka (Jul 4, 2008)

MKIGTITDI said:


> Thank you both for your advice. Would running my current knock box be suffice for the timing for now? Svedka ive look all through that post for most of my info and i thank you for re-posting it. I was trying to see if maybe anyones done it on a counterflow horizontally placed motor. I sa the guy with the pointer but his is a little different then mine.


 you will defenitly be a one off although i did find this http://www.clubgti.com/forum/showthread.php?t=153037&page=2

and yes your factory knockbox will work but you will have to fab a full throttle switch up 



Svedka said:


> As far as ignition systems go you can do lots of different stuff just really depends on what you want to spend money and time on :beer:
> 
> 
> 8v can use vac adv dist
> ...


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## MKIGTITDI (Aug 25, 2007)

I hate to say it but that gave me an idea on a fast and easy way to get a manifold up and running until i could make a nice custom intake.


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## MKIGTITDI (Aug 25, 2007)

So ive ordered my carbs needles and the fuel pump and the rest of the gear are coming on tuesday!!


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## MKIGTITDI (Aug 25, 2007)

I got my carbs today and ill be ordering the rest of them tomorrow. I'll post plenty of pics and updates.


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## MKIGTITDI (Aug 25, 2007)

The rest of my parts are ordered and on their way!!! Heres the before pics and a pic of the old mani!!


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## MKIGTITDI (Aug 25, 2007)

Should get all of my parts tomorrow just in time for the weekend!! So i there for should get everything but the manifold doe this weekend. Anybody know someone with a tig welder in southern oregon?


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## MKIGTITDI (Aug 25, 2007)

Goodbye fuel injection...NO MORE CIS!!!!!!!!


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## MKIGTITDI (Aug 25, 2007)

Everything is done minus the intake!!! New pilot and main jets are installed, Fuel pump is installed and wired in. Once i do the intake mani and throttle and choke cables shell be sounding mean!! Should be running in the next week!!


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## MKIGTITDI (Aug 25, 2007)

Broke one of the slides while adjusting the needles in one of the carb bodies But on a lighter note got the coil re-located and have a rough idea where everythings going to sit.


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## Svedka (Jul 4, 2008)

[No message]


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## MKIGTITDI (Aug 25, 2007)

Thats giving me more inspiration!! Still need to find someone with a welder that i can weld aluminum with to get the mani done. Will resort to a wire if need be.


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## Svedka (Jul 4, 2008)

:beer:


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## MKIGTITDI (Aug 25, 2007)

So the vaccums done up the coils relocated and wired in now i just need to finish my damned intake mani!!!


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## MKIGTITDI (Aug 25, 2007)

So I got my intake fit up now I need to get it welded and face the runners up. Before you go off on how it looks realize its not finished and I only had a portaban, file and a small spool gun. 

















 Oh and i got my silicone today!!! Should get my airfilters tomorrow.


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## MKIGTITDI (Aug 25, 2007)

Getting everything welded up and finished on monday or tuesday next week!!!


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## bubba_vw (Dec 3, 2008)

nice. u should start to make some manifolds for bike carbs. i would buy one!


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## MKIGTITDI (Aug 25, 2007)

I might look into it once i build my final one for this one. Im going to be cutting out a manifold plate and building runners off of the plate for my final piece. Oddly enough it should be an easier process then cutting up the old cast manifold like i did with this first one. Ill be selling this first one once i build my nicer manifold.


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## MKIGTITDI (Aug 25, 2007)

Got the filters today heres an idea of what it will all look like by this time next week only in the car and making noise....


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## MKIGTITDI (Aug 25, 2007)

So i may have found some inspiration on a future upgrade to do before i go turbo diesel in a couple of years!! These are R1 carbs running boost!!


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## MKIGTITDI (Aug 25, 2007)

Finding alot of info on how to turbo these carbs from a surprising source. people have been boosting these carbs for years on snowmobiles.:thumbup:


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## MKIGTITDI (Aug 25, 2007)

Okay so my research has lead me down a verybad road. Im going to start to set aside some extra cash and start picking up parts little by little to turbo this beast.:laugh:


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## MKIGTITDI (Aug 25, 2007)

Just dropped my intake sections off with the welder. Should have it back by sunday and have my car up and running again by monday or tuesday.


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## MKIGTITDI (Aug 25, 2007)

Its welded up now i just need to face up the runners and hook everything up!!:thumbup:


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## MKIGTITDI (Aug 25, 2007)

Got it running after dark last night and discovered im leaking fuel but couldnt figure out where it was coming from. Going to figure that out today and we should be golden!!

__
Image uploading. Refresh page to view


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## STEALTHCORRADO (Oct 14, 2005)

looks good, hope it works for ya:beer:


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## MKIGTITDI (Aug 25, 2007)

Fixed the leak!! Tomorrow ill get the choke and throttle cable hooked up and get video of her maiden voyage!!:laugh:


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## sarcastro (Jun 3, 2010)

how much have you spent on this?


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## MKIGTITDI (Aug 25, 2007)

total with paying somebody to weld my manifold im at roughly 500


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## sarcastro (Jun 3, 2010)

sooooo any running videos?


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## MKIGTITDI (Aug 25, 2007)

Yeah im trying to figure out an issue with the floats right now so its leaking fuel.


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## MKIGTITDI (Aug 25, 2007)

Solved the problem the float was horribly off in the number 2 carb. Got that fixed as well as went back to the stock pilots now shes running and not spewing fuel everywhere!! Everybody counterflows are a go!!!


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## MKIGTITDI (Aug 25, 2007)

Heres a pull as promissed. I slipped launching and im at 60 at the top of 2nd.:laugh:


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## mjulezjr88 (Jun 13, 2007)

****ing awesome! :beer: :beer: :beer: to you my friend!


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## shurik06_83 (Oct 19, 2006)

this might have been saide but why not stay with a aba head and have the carbs out front 

my biggest thing is the exaust mani is right under the carb and thats never a good combo 

but my hat comes off to u for doing it


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## MKIGTITDI (Aug 25, 2007)

It really doesn't heat up the carbs as bad as youd think and with how I made my manifold adapter it helps to keep things cooler. Plus I don't have an extra built ABA head just lying around.


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## sarcastro (Jun 3, 2010)

What exhaust are you running? it sounds nice!


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## Svedka (Jul 4, 2008)

It's a counterflow with carbs lets face it you will have heat soaking issues but lots can be done to reduce the amount of soaking, I'f you live in the city and there is bad traffic it would be a good idea to do as much as possible for heat soaking. Not to mention colder intake means more power:thumbup:

Info on how power gaskets evoheatshields work
http://www.newsouthperformance.com/gasket.htm

Things that can be done for heat soaking issues with a counterflow head this also applies to digilag users:beer:

1st power gasket:thumbup:
http://www.evolutiontuning.com/evoheatshields18SOHC8V.htm
2nd [email protected] ceramic paint the exhaust manifold and down-pipe or buck up and do it professional
VHT make a good product
3rd wrap the header with header wrap 
http://www.jegs.com/i/JEGS/555/32052/10002/-1?CT=999 or ebay or wherever just make sure you follow the directions 
4th [email protected] ceramic paint the intake manifold or buck up and do it professional use what you had leftover from the downpipe:thumbup:
5th make heat shields for in-between the exhaust manifold and the silicone couplers or carbs








these are DCOE's but the same idea applies opcorn: Borrowed pic:thumbup:


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## G_Lader_91 (Dec 28, 2006)

Bumping this from the dead. Just so I can find it easier :laugh: Too much good info here. Going through this now on my rocco.


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## @VR6 (May 26, 2014)

hi, 

I use R1 carbs on my Matra Murena.

Now i am using a aluminium custom inlet manifold, i want to rebuild it in RVS. 
The new RVS should also have a valve on each tube to use for carburator synchronisation.

On my current setup the carbs are placed almost horizontal.

Now i am rebuilding the manifold, would it be a good idea to put the carbs more vertical ? 
This because on the bike they are also placed more vertical or would this make no difference ?

thanks


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