How do you clean out a motorcycle that will not start simply because the gas was left turned on?

Answer 1

Shut off fuel tap and remove sparkplug and crank engine over for 10secs or 3-4 kicks on the kickstarter then let sit for 10mins, install sparkplug ensure choke is off and crank again while holding throttle open full or butterfly on the carby open full until it starts then turn fuel tap open. To stop the problem reoccuring remove the bowl off the carby and inspect float needle and seat for gunk buildup if it is gunked up then remove carby and remove all plastic and rubber parts like float,bowl gasket and float needle and clean with carby/throttle body cleaner also clean out fuel tank with clean fuel, one way to keep this problem from happening is i just run a tank of premium every couple of tanks as the premium has anti-gunk detergents used to keep injectors in cars clean.

Also remove the overflow external screw from bottom of the bowl and make sure the overflow pipe is not blocked, if it is blocked then the carby will overflow out the jets into the inlet manifold instead of out the overflow located at the bottom of the bowl(if you have a small puddle of petrol under the bike after extended rest periods then chances are it aint blocked) try not to adjust the float if your not sure how to properly and just replace the float needle and/or float if you suspect they are past service limits as adjusting the float now may incur more adjustments when the parts wear past usable limits down the track, imo if you don't know how to adjust the float properly then don't ;)

To check float operation without removing bowl just install a small clear peice of hose to the overflow on the bottom of the bowl, stand bike up straight and lossen overflow screw and turn fuel tap in the on or reserve position, hold hose against carby without getting any kinks and the level should be no greater then where the join where the bowl meets the carby, infact it should be around 5mm-10mm below the join on most carbs.

sounds like you have stuck floats in the carbs, or carb. May have some foreign material that got stuck in the needle valve holding it open causing the engine to flood. You can either remove them or take the bowl off and clean it be careful, then adjust floats if they need it. And maybe run some Marvel Mystery Oil, get at Walmart, a little bit, through your next tank of gas to clean out tank and carbs. Won't hurt bike.

That previous answer is a little vague. Here's what you do: If you can take your carb off, you can most likely clean the carbs yourself. Go to your local auto parts store and get the carb cleaner that comes in a can that looks like a paint can. After you get the carb or carbs off the bike, carefully and slowly take the screws off the bottom. This is the float bowl. Be careful not to rip or stretch the gasket if there is one. You'll notice the float. Slide the pin out. Remove float and watch for the float needle. Note its position and where it fits into the carb. Now, you'll see a few brass fittings, some look like a flat screwdriver could take them off. Do it. Others might be a 6mm or 8mm wrench. Do those, too. More complex and modern carbs have more components. You may want to remove the tops of the carbs and take everything out, but this usually isn't necessary. Take all of the metal pieces you just removed (no Rubber) and drop them in the ChemDip carb cleaner as per the instructions. 30 minutes is good over night is better. If you're scared take your carb(s) to the bike shop and ask nicely if they'll slide your carb in on the side and clean it....ask and ye shall receive...

In other words "How do I remove a flooded condition?"

A. Shut off your fuel valve.

B. Open your throttle slides/butterfly and keep them open, while;

C. engaging the starter, until;

D. your engine fires and starts.

E. Open the fuel falve.

This should remove the excess fuel condition. Be aware that the starter is not designed to be "layed on" for too long.

Remember to shut off your fuel valve after turning off your ignition circuit so as to avoid a future occurrence of this problem.

Along with everything stated above,change your oil and run a quart or 2 through then change your oil again..I have a carb 4 wheeler that had the fuel left on for too long and the carb took in so much fuel that it actually started overflowing fuel directy into the engine.Ended up having more gas inside my engine than oil.I got lucky and drained it before I ran it..If I ran it, I probably would have a rebuilt engine right now.