Moss Motors, Ltd

Having problems with mini checkmate 998cc running rich, there is a real smell of petrol from the exhaust. Can any one tell me what i have to do to stop this.

I can think of a couple of things to check. If this suddenly started, I first suspect a problem with the needle valve that regulates the fuel flow into the float chamber. It will be in the float chamber cover where the fuel line is attached. If it is stuck open, instead of cutting off the supply of fuel to the float chamber when the float reaches the proper level, fuel will continue to flow.

 Then there's the air/ fuel mixture to consider. If the needle valve and floats are operating right, use the air valve piston lift pin to raise the air valve.

 If the engine picks up speed then the mixture is too rich and you need to adjust the mixture, by turning the jet height adjustment so that the jet is raised, leaving a smaller annular space between the tapered metering needle and the jet's opening. 

 This might help:

http://sw-em.com/su_carbs.htm

 or this depending on model:

http://www.zparts.com/zptech/articles/mal_land/ml_sucarb2/images4/SUcarb_111601d.htm

Thanks for your reply. Have tried moving the jet valve and this, i think has worked as the smell of petrol as now gone and the engine sounds to be running smoother. Thank you once again.

No problem, Giz. One more thing I'd do is smell the oil on your dipstick. If you detect the smell of gasoline, change the oil.

 Depending on the circumstances the rich mixture may have diluted your oil.

 Keep playing with the ignition timing and carb mixture to find a sweet spot that your engine likes. With age, you can't always depend on the timing marks to be as relevant as they were when everything was new.

 Happy Motoring !  pb

Gizzmo,

Only a thought, but I've been there myself, what state are the air cleaners in? Even clean ones significanly richen the mixture when you put them on, I try and remember to back off a bit when reassembling, to compensate.

Cheers  - - steve

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To a man equipped with only a hammer, most problems look like nails