Guys,

I have toyed and toyed with different jets for a while now and still find that I walk out of my car smelling like unburnt fuel. Is it possible that large jest can produce this issue. At present i have 132 and 135 on. Are these still too large. The engine has a mild cam on it only.
SOmeone please shed some light. The smell out of the exhaust is literaly like its raw fuel. If i screw the mixture down the car stalls...so what the hell is it?

Rod

The mixture screw near the base of the carby.
Screw it all the way in-then unscrew it 2 1/2 turns.

Thanks MAXRS done that many times to try and get to sweet spot and yes its around 2.5 turns. Still nothing

Rod

Just to rule out the obvious issues - have you checked your fuel lines for leaks?

Hi Rod,

Any cam with reasonable overlap will allow unburn fuel into the exhaust and no amount of tuning the carb will rectify that. The Air Fuel mixture will be correct for combustion, but a portion of it is flowing into the cylinder and out the exhaust on each cycle. The only way to rectify it if this is what is causing the smell is to go to a std cam with minimal overlap.

Regards,

Phil.

HMMMMMM, i see what your saying and that makes sense but it never used to stink so bad....I suppose the tappets need to be retightened, this could change the lift slightly...and perhaps assisting with your theory.

Rod

Question,

Would a wrong set up of the carbon canister cause this smell. i mean my set up is nothing like the manual. In fact i dont think the tank line is connected. Having said all this. I have researched this topic and its bloody confusing. I recall not having it like the manual and not having the petrol smell.

Rod

I think the issue is the power valve. Has anyone had any issues with this damn valve causing over riching at low revs and also causeing hesitation. My car screams nicely at high revs but hesitates on take off. The carbi is clean and has been kitted recently

Rod

Its worth a try Rod, a quick recheck of the carby wont hurt

Hi Rod,

The Main jet sizes you have mentioned are about right for a standard engine and depending on the cam timing may still be all right. First eliminate the vacuum advance by disconnecting it and try a couple of degree of mechanical advance. If this does not fix the hesitation check the mechanical advance does not increase in a jump with a timing light. and before anything ensure you float level is correct in the carburator and get the idle mixture correct for your selected idle speed.

Once float level is checked first and the air cleaner is fitted.

Usually it is a combination of idle mixture setting and or ignition timing to eliminate the flat spot. provided the carburettor is in good shape.

The smell could be excessive fuel level in the bowl which will go through the idle jet and main jets into the carburator intake even after engine shutdown beware of fire risk if this is happening. It will also cause hesitation due too rich from idle.

My 2 cents worth
Cheers