Honda cx 500 1981 motorcycle leaking gas out the carbirator once cool will not start what could be wrong have to shut fuel line off?

Answer 1

Leakage in the carburetor means that the gasket is worn out, just take it to the mechanic and tell him to clean the carburetor. You will find out the real fault in the bike. And also try to clean up the spark plug of the engine head because it is the main cause of not making the bike start when cooled off.

Sorry to step on any toes but I have a few more ideas and one question. I have about 30 years of experience with Japanese motorcycles but only 6-7 with Honda. First question is "does the Honda have a center kick stand"? If so grab on and pull it up on the center stand just to see what happens. My guess is that this will not change your leaking gasoline condition but will equalize the gas left in the float bowl and may be just enough to stop the leak. In a way, you are lucky, please let me explain. When most gravity fed carbs

stick with the internal needle in the off position or in other words - no gas and are quite the pain to get them back to run mode after winter storage. This is not your case. If you see or smell gas leaking from the float bowl gasket I'm sorry to say that you have issue with needle and seat inside. I can't count the number of times I had to remove the carb

and head for the bench. You will need to remove the carb

from the bike to gain access to the float, needle and seat. PLEASE PAY ATTENTION TO THE ORIENTATION OF SLIDE AND REPLACE IN THE SAME CLOCKING. Without doing this you will have a throttle that will not return to normal home position and will idle over 3000 rpm. Back to your subject you will need to remove the float that rides on a brass pin. AFTER you remove the float bowl everything will be right in front of your eyes.

1) Put bike on center stand

2) remove air cleaner box and the 25-30mm rubber hose that connects your air cleaner to the intake of the carb.

Take time during this step as sometimes they can be difficult to get seated where the factory put it. Do it. You can ruin an engine without an air-box

and will want to know why your engine has low compression

3) Usually a clamp not unlike a hose clamp will be holding the carb

to the rubber intake manifold. Loosen but do not remove this clamp and the carb

should be ready for removal and inspection.

4) Take carb

assy

to bench and remove the (4) four screws holding the float bowl to the upper body. Like the earlier post says to inspect the gasket between the float bowl and the upper body of the carb.

Replace as needed. The root cause of leaking gas is due to a sticky float, needle and seat. This is the part that allows gas from your tank to gravity fill the float bowl. Your problem is that is is not shutting off when the float reaches "full" leaving that as main problem. Your engine is flooded with fuel and when you try a hot start after 20 mins

you are stuck. Clean the pointy end of the needle and inspect for wear. Clean the brass seat area and take care that EVERYTHING goes back in the same position it was removed from. All needles have a gasoline resistant tip and will show rings when they are shot. In the old days they were solid brass. Replace any suspect parts and with God's help you should be up and running in about an hour.