1980 Yamaha Carb Problem
aragoth86
04-15-2006, 10:40 PM
I have a 1980 Yamaha Midnight Special XS 850. It is leaking gas from the air intake on the leftmost carb. i just rebuilt all three. anyone know why this is leaking?
*edit*
I forgot to mention that it only leaks when turned off. it doesn't leak when it's running
*edit*
I forgot to mention that it only leaks when turned off. it doesn't leak when it's running
UncleBob
04-15-2006, 11:25 PM
I have a 1980 Yamaha Midnight Special XS 850. It is leaking gas from the air intake on the leftmost carb. i just rebuilt all three. anyone know why this is leaking?
*edit*
I forgot to mention that it only leaks when turned off. it doesn't leak when it's running
there are two problems here. One, the petcock is leaking (I'm assuming its a vacuum operated petcock...if I'm wrong, disregard) the other problem is you have a leaking float valve.
Unfortunately, that means your carb "rebuild" didn't take. If you paid a shop to do the rebuild, I'd definitely take it back. There is a couple things that can cause this. Sometimes its simply a sticking float/valve that a light tap with a screwdriver handle will solve, sometimes its sediment from the tank contaminating the seal of the float valve (tank rust for example), and sometimes its the sealing surface itself is sub-optimal....but whichever it is, it needs to be torn down again, inspected and fixed.
BTW, even though you might not notice a problem while the bike is running, its leaking then too.....that cylinder is probably running richer than it should at idle.
*edit*
I forgot to mention that it only leaks when turned off. it doesn't leak when it's running
there are two problems here. One, the petcock is leaking (I'm assuming its a vacuum operated petcock...if I'm wrong, disregard) the other problem is you have a leaking float valve.
Unfortunately, that means your carb "rebuild" didn't take. If you paid a shop to do the rebuild, I'd definitely take it back. There is a couple things that can cause this. Sometimes its simply a sticking float/valve that a light tap with a screwdriver handle will solve, sometimes its sediment from the tank contaminating the seal of the float valve (tank rust for example), and sometimes its the sealing surface itself is sub-optimal....but whichever it is, it needs to be torn down again, inspected and fixed.
BTW, even though you might not notice a problem while the bike is running, its leaking then too.....that cylinder is probably running richer than it should at idle.
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