Le Mans Mk5 (1991) ditching petrol

I am having a bit of a problem with my Lemon and was wondering if anyone on here could help. It starts fine having put a heavy duty battery on but if I stop and put it on the side stand it invariably ditches an amount of petrol on the LH side of the bike - roughly speaking about a float chamber full. I replaced the gaskets a year back so I don’t think that’s the problem. Any ideas anyone?


Check the operation of the floats and needle valve to shut off the fuel supply. Always turn the fuel taps off when parking the bike. Does this model have manual taps or are they the auto type? If auto, are they shutting off correctly?
I have heard comment that floats have distorted and rub on the side of the float bowl, preventing them rising fully with the fuel level.

My pal’s Serow XT225 does the same thing from its single carburettor. Considered opinion is that it leans far enough over that it is changing the float height enough to cause the carb to flood. So he just switches the fuel off whenever he parks it and we otherwise don’t worry.

I have a Mark V.

It doesn’t ever leak fuel, so what you are seeing should not happen. You should always turn the fuel taps off though when stopped.

It is easy enough to take the float bowls off and check the operation of the floats. You could also check where the fuel lines goes in and the fuel filter assembly, gaskets etc. Always worth having a quick look at the fuel filters as they can get gummed up a bit.

One of the great things about these bikes is that it is all so accessible. Changing the air filter or oil filter slightly different story mind you.

Much obliged all.
I’ll have the LH carb off and have a look.