Join Date: Sep 2003
Location: Auckland New Zealand
Thanked 34 Times in 31 Posts
Rep Power: 13
Re: Fuel in oil - where to start?
IMHO it’s not the carb. If the carb was being so overwhelmed by fuel line pressure that it is contaminating the oil then that engine would run very badly or not at all. It takes very little extra fuel to flood an engine and it takes a huge pressure to overcome a needle and seat and bypass into the full float chamber.
If the needle and seat is dodgy, the engine will also run badly or not at all and the engine would definitely not start if there was enough fuel percolating into the cylinders to run past the rings into the crankcase. That's a really long shot as far as I'm concerned.
If you have a mechanical fuel pump on the side of the engine I would bet a considerable sum on the diaphragm being torn and allowing fuel into the crankcase. Start there – take the pump off, open it and closely examine the diaphragm. It will still pump even though it leaks fuel.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
"Two possibilities exist: Either we are alone in the Universe or we are not. Both are equally terrifying."
Arthur C. Clarke