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Author Topic:   Engine stumble on restarts
TxHobby3
Dirt Roller

Total posts: 9
posted May 23, 2004 05:40 PM  
OK heres the deal. We finally got the car up to speed and pulling hard. On the initial start of the race the car is great, all the way up to the first caution. When I resart after the caution, the engine stumbles bad( usuallly loose a couple of spots!) Runs bad for about have a lap then clears up, and will run great again until we get another caution, then it starts over again. Any ideas?

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Gas on it!

hobby9
Dirt Roller

Total posts: 17
posted May 23, 2004 07:21 PM  
Vapor lock, maybe?

gonfast
Dirt Full Roller

Total posts: 67
posted May 23, 2004 08:28 PM  
what kind of carb on what kind of engine

TxHobby3
Dirt Roller

Total posts: 9
posted May 23, 2004 09:45 PM  
It is a rochester 2bbl (required) on a chevy 350.

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Gas on it!

avila
Dirt Freak

Total posts: 217
posted May 24, 2004 10:42 AM  
what is the rpm range difference on the restart compared to when get at a half lap?

what is rpm diff compared to start of race
and restart after a caution?

what is the stumble like. does the car hesitate/bog/jerk and then pick up, or is it a constant stumble through the rpm range?

BIGDADDYBOZ
Dirt Freak

Total posts: 466
posted May 24, 2004 11:07 AM  
I would check the float level and make sure there isn't any dirt in the carb. I had this prob and found a piece of rubber on a pick up tube on the squirters.

TxHobby3
Dirt Roller

Total posts: 9
posted May 24, 2004 08:46 PM  
It Stumble through the whole RPM range. RPMs on restart are 2000 give or take a little depending on the leader. We are going to pull the carb at take a look at it.

maniac motors
Dirt Maniac

Total posts: 128
posted May 31, 2004 01:06 PM  
if you cant figure it out then send it to kinetic performance. had a similar problem last year and was pulling my hair out.sent carb to him for rebuild and it is awesome almost think i put a 4 barrel on. there is a link on the home page of this forum to kinetic performance. i built my own carb before i sent it to him and i will tell you theres no comparison. Dayton is a great guy, down to earth and great service.

racer17j
Dirt Forum Champ
Total posts: 5390
posted May 31, 2004 06:37 PM  
thought mine was heat related also i even went as far as insulating the fuel line to carb to prevent heat and still did it. i did stretch power piston spring and that helped but not as much as having carb blueprinted by kinetic

TxHobby3
Dirt Roller

Total posts: 9
posted June 05, 2004 09:03 PM  
I lucked out and found one of the big carbs at the wrecking yard. Got rain out so I haven't got a chance to check it out though.

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Gas on it!

    

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