Guest Posted August 19, 2008 Share Posted August 19, 2008 Appreciate any help with this one, forgot to turn off petrol tap one time, I remembered about 3 hours later and returned to bike dripping petrol on floor, left bike overnight but found very difficult to start next morning, when it eventually did start, it now continues to pour petrol on to floor via what I presume is the carb overflow pipe, anyone know how the carb fuel height is controlled on the mikuni carbs? been looking for some form of needle valve, but no sign of this type of fuel control in any of the manuals i have read. Quote Link to comment Share on other sites More sharing options...
Stu Posted August 19, 2008 Share Posted August 19, 2008 the float will be stuck open time for a quick strip and clean then all should be as good as new Quote Link to comment Share on other sites More sharing options...
rollazuki Posted August 19, 2008 Share Posted August 19, 2008 each carb will have a float which controls the fuel height. This float will act upon a needle valve, which directly affects the petrol feed into each float bowl. Remove the carbs, tip em over, remove the float bowls, and see the floats. The needle is at the hinge end of the float. There are several issues here.1 there is a leaking float which has taken on petrol, and is not closing the needle. remove floats and shake to hear for liquid inside.2 the needles are worn or damaged, and as such leak fuel into the chamber.3 the float heights are out(usually blamed, but often not to blame) after all, they never get knocked or tapped, so why would they suddenly be 'out'As a rule of thumb on a multi carb bike, check the float heights on each carb, if one is adrift, make it the same as the others, or check against factory spec if you have it.When that is sorted, bung em back on the bike.NOTE!!!If fuel finds its way outa the overflow, there is also a good chance its found its way into the cylinders. This can hydraulic lock the engine and cause massive damage, or sneak past the piston rings and dilute the engine oil, again causing excessive wear.Dip the oil, if it smells petrolly, bin it and change oil+filter. Quote Link to comment Share on other sites More sharing options...
Guest Posted August 19, 2008 Share Posted August 19, 2008 have you tried giving the float chamber a knock with screwdriver ( gentlish tap) see if this cures it as mentioned float needle may be stuck and sometimes a jolt will allow it to slide back but in long run strip & clean Quote Link to comment Share on other sites More sharing options...
handyandy24 Posted August 22, 2008 Share Posted August 22, 2008 am i meant to turn my petrol off when not using the bike:O ? Quote Link to comment Share on other sites More sharing options...
flipper Posted August 22, 2008 Share Posted August 22, 2008 ZX7R has a vacuum tap doesn't it? (PRI position), so you can't. Quote Link to comment Share on other sites More sharing options...
handyandy24 Posted August 22, 2008 Share Posted August 22, 2008 duno it has an OFF position tho Quote Link to comment Share on other sites More sharing options...
flipper Posted August 22, 2008 Share Posted August 22, 2008 then yes, you should turn it off. Quote Link to comment Share on other sites More sharing options...
handyandy24 Posted August 22, 2008 Share Posted August 22, 2008 ive never had a problem, left it standing for a week b4 as well. best start :S Quote Link to comment Share on other sites More sharing options...
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