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Tue Dec 26, 2006 4:34 pm

hey everyone,
I have a 1914cc with an engle 120 can and 040 heads. I am running a single weber 40 carb. Is this capable of giving the engine enough fuel? I cannot give it gas right away when i shift or else it will stall or hesitate until it dies out. but once i have the motor running at a high RPM i can wind it out, but hesitates as soon as i shift again. What could the problem be? How can i adjust my carb to give it lots of gas?
Thanks everyone

Tue Dec 26, 2006 6:38 pm

Sounds like you sucked some dirt in the idle/off idle circut??

Tue Dec 26, 2006 7:15 pm

Did you just put this carb on this engine? If so you may need to have it jetted and other work done to the carb. I just went through this same kind of problem with my 1914 engine, but I ended up taking it to someone that know's how to make the correct adjustments for a single carb set-up. The jet's were of the correct size, but the venturis were sized too big. I have a single 40mm dellorto with I think 32mm venturis, but they were changed to 27mm venturis and now this engine kicks A$$.

If indeed you just put this carb on, then this is somthing to think about.

Check and see what size venturis are inside your carb.

Tue Dec 26, 2006 7:35 pm

New carb, old carb? IDF, IDA DCNF/L? Too many variables without the specifics, but Michael is on the right track. Center mounts are a pain to dial in. The hesitation and falling off at idle and off-idle is definately an idle jet issue. You can switch the venturies as suggested, or step your idle jets up one or two sizes. Your fuel mileage will suffer as well, so take note.

Rick

Tue Dec 26, 2006 7:52 pm

It is a weber IDF 40 with 28 venturis. the carb isnt that old. but i dont know, this is how i bought it. U guys think dual carbs are easier to tune the motor. i have the dual carb kit, im just not sure if im capable of installing it properly.

Wed Dec 27, 2006 7:26 am

28's should be fine for a center mount. The first thing I'd do is tear the thing down and really give it a good cleaning and rebuild, just for safe keeping. If you don't feel comfortable doing that, find someone who can. A bad pump diaphram can wreak all sorts of problems. Get some literature on tuning the Webers. Learn how to set the mixture screws - I'd actually try this first - if they're too far in, you're setting a really lean mix at idle, and can cause the symptoms you describe. Dual carbs are twice the effort to keep in tune, but if you have the patience the troubleshoot, they are worth the effort, so long as they are matched to the motor.

Rick

Wed Dec 27, 2006 8:18 am

thanks guys..i'll try cleaning it. if that doesnt work, im puttin the dual carbs on