1200GXman, fuel injection throttle body sizes and injectors are chosen to suit the horsepower target of the bike.

Bike engines make a lot more horspower per cc then pushrod dattos do, so if your motor is a fairly standard A14/15 or even a warm A12 then any FI setup from a 600cc bike engine will be fine.

If you have a worked A12 or mild A14/15 then look for a setup from a 750cc (ie GSXR) and for turbo application look for a setup from a 1000cc

ball park figures for late model unmodified fuel injected bikes are (roughly):

1000cc make around 145 rwhp (160 crank)
750cc make around 130 rwhp
600cc make around 110 rwhp

The keihin brand throttle bodies are used on nearly all brands of bike, yamaha, honda, suzuki, triumph etc.

Using a standalone fuel computer would probably be the best bet as I dont think the bike ones will be of any use to the average A series as the fuel maps would be for much higher RPMs

id say around 28-30 for a bog stock small block aseries
for the bigger motors and worked small blocks id say 32-38

Pretty much any size will work.

A better question is which are most optimum for an A12 engine with stock cam.

I am setting up 4x32mms ex Suzuki GSX11GK. Most large bike carbs are vacuum operated. These ones are a manual type, they are much easier to balance and keep in tune. But they will all work very well. If you can get a 36mm Flat side setup they would be spectacular. I ran them on all my race bikes back in the good o'l days but very rare, very expensive.

Quote:

Check this link out, it's a guy locally that built his own ITB's for his GA14 Sentra. He used ITB's off a GPZ 1100 Kawazaki (35mm), it worked out quite well for him...

EDIT: Oops, forgot to post the link...

http://www.teamdragon.co.za/forum/viewtopic.php?t=714

Quote:

PIGDOG is working on a custom manifold for GSXR throtle bodies

Cyclons8- dude that is a hawt little 1000, I can tell by just seeing the bay!

Sorry to hijack this thread, but what size quad fuel injection throttles will work for A12 and A14 size engines?
It will be bike quad fuel injection throttles.

Anybody know of someone that did bike fuel injection on a A12 that worked?

pictures speak many words

Yes, that'll work with a standard camshaft.