hey, tell me if this sounds feasible... i've got an old 1992 CBR600f and its in at the mechanics as it was running funny... would wind down and loose power and stop every couple of kms.

He reckons the needles in the carb were worn and flooding the carb. That sounds feasible... but then he tells me that the carb was over flowing on to the top of the engine... pooling petrol at the plugs which had over time seeped into the engine... he reckons the oil is contaminated with petrol and it needs a flush and oil change.

He reckons when he started it the bike blew a 3 metre jet of petrol out the exhaust... nice... lucky it didn't ignite or i'd have been well pis*ed off!

Seems a bit dodgy though as if the petrol leaked in the plugs itd be in the cylinder... surely there is unburnt fuel in the cylinder everytime you switch the bike off... how come that doesn't contaminate things...

he reckons that he had seen another bike with the same problem that had along with the normal 3 litres of engine oil, an additional 3 litres of fuel mixed in there and that if it ignites it'd be a BIG bang

any ideas?

 

Hopefully it didn't bend any valves/rods with that much liquid in the cylinders. Liquid won't compress like the air and fuel vapor will. If I'm understanding you correctly, he said the fuel was getting on top of the cylinder head? If that was the case, the fuel would evaporate before it could ever leak down the plug threads. I think what he meant was the fuel was leaking into the cylinders on top of the pistons after shut down from the overflowing carbs. It could then leak down past the rings into the crankcase, and have all that fuel in the cylinders to blow out at start up. You should change the oil. Don't ride it till it's fixed!

Good luck,

Bob