I'm losing gasoline from the overflow on my Carb on a 450-s. 13800 mi. Replaced the needle valve last spring when the proplem first occured. Am I correct in my assumption that the carb will have to be replaced? There is no way to adjust the float level, nor tweak the needle valve for more seat pressure. Thanks for any advice.

Go forth and ride!!

Going to Az for a few well deserved days in the warmth.

 

Have you tried just cleaning the carb with a carb cleaner. It sound like the float is sticking or you have somthing stuck in the float valve. And if that does not work you should be able to just replace the float valve and float instead of buying a whole new carb.

 

Madmax speaks truth.

Probably dirt in the area of the float valve and seat--madeningly hard to clean, sometimes. (If the gas is really GUSHING out, your float may be stuck or filled with gas instead of air and isn't even TRYING to shut off.)

Try carb cleaner first (Yamaha makes the best killer cleaner, if the over-the-counter stuff doesn't work); then disassemble it and scrub it if you have to--even consider replacing the float valve (expensive!) if the tip is worn or distorted; a good cleaning should fix everything, but a tiny piece of trash can be hard to find and remove.

Clearly, your float valve isn't shutting off.

Diogenes

 

Go to wal-mart and buy a spray can and a liquid can of Chemtool B12. The spray can is $2.57 and the liquid is $2.37. Pour the liquid in the bike and run it for a while. It should clear. If not, take that carb apart and spray with B12. The stuff is incredible. You will be happy. If that dosent work just replace the float and needle. That should do it. I had the same problem on my TRX 250 '86. Throw some B12 liquid in you car also, you will notice more power and better mileage within a half a tank.

 

Assuming the new float valve you bought is not itself defective you could have a problem with the valve seat. Float valves & seats should be replaced as a unit to insure proper seating. When you replace them both as a unit it would be wise to check the float level at that time also. You can measure it with the float tang just barely resting on the valve. Various carbs measure from different locations. Check your shop manual for the right specs. The float level is adjusted by bending the tang on the float very slightly.