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Carb question

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fasttommy

Member
What's a good starting low and high jet size for a engine Cl2 cam 35 Deg timming it's got the Ksr weenie pipe I have 37 h 26L it runs choppy idle screws all the way in an low mixture screws only 1/4 turn out. If tried going in and out with low mixture screw. No luck it excelerates fine
 
Chopped on low end is good..you are within reasoning on jet sizes..you did keep your own rings on their local speed jet stem right?
 
Jerry meant to ask if you still have the O-rings on the low speed jet...make sure at least the top one is on it
 
The air passing through the low speed circuit encounters the restriction at the pilot jet, this acts exactly like the main venturi of the carb. Fuel is forced up from the float bowl to mix with the passing air. This is delivered to the engine through the pilot holes on the engine side of the throttle plate, you can control how much flow there is by opening or closing the pilot needle screw. You can control the amount of fuel by enlarging the jet in the plastic pilot, by leaving the lower O ring of you will allow extra fuel to leak up past the plastic jet, if you leave the upper o"ring off you risk air leakage into the circuit which will cause a lean situation.
 
Personally I would leave the bottom o-ring off, and if you feel it still stumbles or is choppy on low end, go to a size bigger pilot jet or double check your gaskets for air leaks and the insulator for cracks. I always increase pilot jet size if I have a stumble on low end, and it always helps unless there is an air leak such as torn gasket or cracked insulator. Some people will use an impact to tighten the carb nuts and this can easily crack the black insulator in a way that you can't visibly see it
 
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