Drove my BIs for the first time today, Taxed it this morning. After an hour i noticed the oil was VERY thin and stank of petrol. The car then began to need the chocke on all the time to stop it conking out when idling, it also guzzels petrol. The car nearly failed MOT on emmisions so i rekon a big problem with carb? it has even had a new float. Any suggestions anyone?? Im dead upset.
I'd suggest not running it much or you'll be looking at a shagged engine
,
never worked on a BIS, so dont know the specific ins, outs & quirks, but,
first thing is change oil & filter,
the petrol is obviously flooding out the carb and at a guess either going in the crank breather when stopped, or washing down past the rings when running,
first guess is a worn/sticking needle valve, or if its adjustable its set too low causing the level in the bowl to be too high,
if theres nowhere to connect a hose on the base of the bowl to check level, you can whip the carb off, remove the bowl and stick it in a clear container(A pint glass used to be perfect for my old mikunis) it should be able to hold a good 2-3 feet head of petrol(use a tube and funnel raised above the carb to measure),
also on some carbs, if the diaphram in accelerator enrichment loop gets a pinhole it can cause strange behaviour like this, but not sure if BIS carb is sophisticated enough to have accel enrichment
, check the manual.
or possibly the carb is getting too hot and the fuel inside the bowl is foaming, causing the bowl too sink and petrol to pish out.
and my last guess, it could be the fuel pump is running too high a pressure, forcing fuel in, not sure if the pump will be adjustable, you can check the pressure with a gauge but a new pump is prob cheaper than a fuel pressure guage.
hope my wild guesses are of some help,
best fix would be sell it and get a proper 126 :wink:
cheers, Richie