Tuning Pinto with Bike Carbs

[CAskew]

Appreciate any help and advice from anyone who has a Pinto with bike carbs.

Engine is a 2L Pinto, Single Overhead High Torque (FR 30) Cam, Carbs are Mikuni from a ZX-6R J Ninja (2000-2002) and a Megajolt ignition system.

RH 2B Plus on a rolling road showed fuel /air ratio was far to lean even though jets drilled to 180. Eventually drilled to 210, however, torque and fuel drop off at 4750 rpm.

Currently Needle jets fitted are 5E18 (outside - 1 & 4 cylinders) and 5E19 (inside 2 & 3 cylinders) and no longer available and advised needle profile needs adjusting/changing.

I would be pleased to hear your recommended jet sizes, needle profile/code and where to obtain the parts from to obtain maximum performance over the full (1,000 - 6,000) rpm range .

Regards

Chris.

[tractor]

have you blocked off the air correctors 

[CAskew]

Appologeise as not sure what and where they are. Photo would help identify

[Foz]

Hi Chris,  I'm sure somebody posted pictures of bike carbs showing what was what and what went where, a couple of years ago. I seem to remember there was quite a bit of info. on them.  It might be worth you doing a search through the forums for them.

Steve

[richyb66]

https://www.rhocar.org/index.php?/forums/topic/49263-carbs/&tab=comments#comment-402824

[CAskew]

That's brilliant info and thanks Richy.

Have saved the pdf and will be looking and trying to take it all in.

Chris

[CAskew]

BTW my manifold was made by Bogg Bros. Might be good idea to email them again for advice.

[RedTrev]

I got Steve Walford to tune Keihin ZX9R carbs to my 2.0l Pinto. After checking the initial condition, he blocked the air correctors immediately. He explained, from his years of experience, that going through the process of slowly opening up the jets, he'd reach the point where he'd have to block the correctors, and then have to reduce the jets back down, often back to the size that they were initially. It might be a better starting point for you to try.