Leaky carb

[prue1]

One of my mikuni BS38's is leaking fuel from the float bowl drain. The aluminum washer seems to be the culprit. I have been unable to locate one of these and even thought that a copper one might work, but I can't find any of these either.

Any suggestions? Thanks.

 

[5twins]

The originals were copper and honestly, I think they work better. It seems Yamaha no longer sells it so a used one may be your only option. They last darn near forever and can be sanded smooth again if they get all grooved up. You might try P.M.'ing DogBunny, he seems to have a pretty good collection of used carb parts.

 

[DogBunny]

Thanks for the plug, and yes, I can sell you a copper gasket.
However, you should be able to get the aluminum to work by annealing it. Hold the washer in a torch flame until it just starts to get red, should take seconds, then let cool naturally. This makes the aluminum soft, and it should seal. (To anneal copper, you heat to bright orange.) There is a really good article on annealing motorcycle washers on the net, try a search.

 

[DogBunny]

BTW, I have never had a leaking drain plug that I couldn't fix by just tightening the plug. Be sure the leak isn't coming from somewhere else.

 

[5twins]

I can't believe Yamaha no longer sells this because if you look it up, you'll see it was used on some of their carbs all the way up into the late 2000's. How can you not carry a part for such late models, and a perishable sealing washer to boot.

 

[prue1]

Thanks for the plug, and yes, I can sell you a copper gasket.
However, you should be able to get the aluminum to work by annealing it. Hold the washer in a torch flame until it just starts to get red, should take seconds, then let cool naturally. This makes the aluminum soft, and it should seal. (To anneal copper, you heat to bright orange.) There is a really good article on annealing motorcycle washers on the net, try a search.

Hey that's good info, I will try it and let you know!

Thanks 5twins and Dogbunny.

 

[prue1]

I heated up the aluminum washer. My washer began to melt before it tuned color (this happened real fast). I pretty much ruined the washer. Maybe I held it to the torch flame too long.

 

[DogBunny]

There is a really good article on annealing motorcycle washers on the net, try a search.

I Googled
"annealing motorcycle washers"
and the very first result was this:
http://www.motorcycle.co.uk/reference/annealling-copper-aluminium-washers

If you need a washer I'll mail you one.

 

[prue1]

I Googled
"annealing motorcycle washers"
and the very first result was this:
http://www.motorcycle.co.uk/reference/annealling-copper-aluminium-washers

If you need a washer I'll mail you one.

Heated mine too long. I have two new washers coming from Yamaha speed and sport.

Thanks.