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Author Topic:   carb help!!
thomas66
Dirt Roller

Total posts: 15
posted January 07, 2005 09:01 PM  
The goodies make it a race engine, there isn't a need for the thing to want to run when its cold, due to cam, timming, carb, and other factors. You're not doing the engine any favors running it like you are.

thomas66
Dirt Roller

Total posts: 15
posted January 08, 2005 09:52 PM  
Have you checked for vacume leaks?

pit_boss
Dirt Forum Racer

Total posts: 80
posted January 09, 2005 09:51 AM  
Thomas66,I think what Gene was wondering about was,"let it run at 3grand for about 45 min" was that your initial fire up when the engine was new, to break the cam in? It does sound like a vacuum leak like S.Ed suggested.Try spraying a chemical around the base of the carb and the intake,if the motor fluctuates your near it.....Jim

racin78p
Dirt Freak

Total posts: 333
posted January 10, 2005 05:16 AM  
Had a vacuum leak once and that's what it did. Had a distributer clamp loose once and it did almost the same thing. The distributor would just barely move (and that's all it has to) and there goes the idle, not to mention timing! Besides those two things, where are you trying to set the idle? Maybe it's too low? Mine is set at about 1300 rpm's, am running a rather stiff cam. Also, be looking at that carb. You could have a problem with it, like float too high or too low (if it is fluctuating check for bad float needle/seat). I bet it's a vacuum leak though. Good luck.

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racin78p
if it ain't fun, then don't run

GARYAL
Dirt Forum Racer

Total posts: 94
posted January 10, 2005 07:29 AM  
I had an idle screw that wouldn't stay put once. car was great running then when you start it up cold you had to adjust it. as you ran it it would work loose then the next time you had to adjust it again. we fixed it by adjusting the car to run both warm and cold then put some silicon around the screw.

thomas66
Dirt Roller

Total posts: 15
posted January 10, 2005 06:27 PM  
A race motor (with some real caming) will always run rough at the first start up when cold. We have to turn up our idle to keep it running till it warms up, then back down to around 1300 rpm's. If you have a vacuum leak, this will increase the difference (from cold starting or hot starting) and yes the motor will still not run great because of the leak. A small leak won't keep a warm motor from running necessarily, but a cold one will be hard to keep running. I have had the problem before. Kind of like you, I wouldn't have thought it to be so. GARYAL made a good point here too. Check the carb out really well. If you don't know Holleys that well, find a good carb man and let him tear it down and take a look. And have it re-built for the heck of it! By the way, just as an "opinion" when we break a new motor in, we get everything set the best we can, then start it up and run it for 20 minutes at 2000 rpm. Everyone has a different way for sure. Once again good luck, and when you get it figured out, let us know!

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racin78p
if it ain't fun, then don't run

fastrack1
Dirt Maniac

Total posts: 145
posted January 12, 2005 07:03 PM  
What advance springs are you running in the distributor.

petordragon
Dirt Maniac

Total posts: 167
posted January 20, 2005 06:47 PM  
check filters and cleanliness of bowels could be a dirt prob.

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