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Author Topic:   C&S Carb Problems
Dirt Roller

Total posts: 11
posted June 12, 2001 07:56 AM
Having problems with a C&S 750 Alky carb. Cuts out in the middle of corners, and lets out at the end of straightaways, acts like its starving the carb of fuel, and its doing it we replaced the needles&Seets,pwr valves, accelerator pumps, gaskets etc....Now its worse and its blowing fuel through the vent tubes. Anyone got any ideas????

Dirt Maniac

Total posts: 134
posted June 12, 2001 07:59 AM UIN: 27426975


Dirt Full Roller

Total posts: 57
posted June 12, 2001 09:01 AM
Sounds like your float(s) are sticking, hanging up, or at least somewhat out of adjustment. Fuel coming out of the vents comes from things such as much too high fuel pressure, or a float level that is very much too high, but a carb that "cuts out" at the end of the straights usually is being run with fuel pressure that is too low or a faulty pump that can't fill the bowl(s) fast enough, so you may have more than one thing going on there.
I can't say what C&S uses for floats, but you may want to try going to a set of "cut" floats specifically designed for oval track racing, if you don't already use them. They help eliminate fuel slosh problems while cornering.
Let me know if you need any assistance finding them, too.

Always glad to help where I can.


[This message has been edited by KPLugnut (edited June 12, 2001).]

Dirt Roller

Total posts: 11
posted June 12, 2001 01:13 PM
The jetting seems to be ok, the temperature
stays around 180 to 200 degrees while racing.

Thanks for the help guys, were still trying
to get it to work, we are going to try changing the fuel pump and checking the floats again and see what happens.....

Dirt Full Roller

Total posts: 34
posted June 12, 2001 10:26 PM
If your floats are brass, check for "crushed" float or floats. This can be caused by one backfire through the carb. Sometimes hard to see, unless you have a new float to compare it to. Will cause symptoms as you described.

Dirt Full Roller

Total posts: 75
posted June 13, 2001 05:39 PM
Check your fuel pickup in the cell and make sure it isn't getting uncovered, sucked up against tank or plugged. As for the fuel coming out of the vent tubes that is definately a float or fuel control problem..Ditto to what the other guys said.

Dirt Roller

Total posts: 25
posted June 16, 2001 10:35 AM
you may want to check the fittings from the tank to the pump. i had a problem alot like yours, and found a fitting that was eaten out causing the pump to suck air at times. it would idle fine, but at higher revs it would spit fuel out the vents from all the air. it does not take long to bust them loose and look. just a suggestion.

Dirt Roller

Total posts: 11
posted June 18, 2001 10:20 AM

I never even thought about that, I'll check it out and see, thanks for the help!!

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