gas leaking under one carb

[speedlimit85]

I just went 1300 mi on a road trip. Bike had no problems. I am back home and I see a drip forming under the middle right carb. I changed the copper washer on the drain plug- no change. I replaced the o-ring on the float bowl assembly- no change.

What is best to try next?

Thank you

[skids]

I just went 1300 mi on a road trip. Bike had no problems. I am back home and I see a drip forming under the middle right carb. I changed the copper washer on the drain plug- no change. I replaced the o-ring on the float bowl assembly- no change.

What is best to try next?

Thank you

Needle and seat in the fuel valve are leaking gas through it, or the float is sticking open, or the float has a hole and not floating (unlikely with 80 carbs as they are plastic, not brass). The float valve needle should be coated with a rubber material (vitron?) You can gently clean it. Also the needle seat can have corrosion or crud preventing a good seal. It can be cleaned with a qtip using eagle 1 polish or the like. The needle pins can sometimes get sticky.

[speedlimit85]

Needle and seat in the fuel valve are leaking gas through it, or the float is sticking open, or the float has a hole and not floating (unlikely with 80 carbs as they are plastic, not brass). The float valve needle should be coated with a rubber material (vitron?) You can gently clean it. Also the needle seat can have corrosion or crud preventing a good seal. It can be cleaned with a qtip using eagle 1 polish or the like. The needle pins can sometimes get sticky.

Yea. I just had that apart. And those parts are less than a year old. But I could clean better.

That bowl had less gas in it, could the bowl be cracked?

[lowprofile2000]

I had those symptoms, leaking from that carb, turned out to be my fuel "T" was shot and leaking.

[speedlimit85]

Where is the fuel "T" ?

[lowprofile2000]

Its goes between the two carbs where the fuel line enters. It is what converts the 1 fuel line into both carbs for one side.


Looks like this. https://m.ebay.com/itm/NOS-New-Yamah...anner=1&_rdt=1

[speedlimit85]

My bike has fuel lines from the petcocks crossing to opposite carbs. I don't see T's or leaks from the lines.

[lowprofile2000]

I assume you have 2 fuel lines and 4 carbs? There is a t joint between the carbs, tough to see. When mine leaked it trickled down the side of the carb, I couldn't tell it was the t.

Not saying that's your problem, just sounded familiar.

[Schming]

Yea. I just had that apart. And those parts are less than a year old. But I could clean better.

That bowl had less gas in it, could the bowl be cracked?

Maybe but not likely.

Fuel level should be lower than top of bowl so if it's the float needles that are the culprit then it'll leak from the air box.

My "G" had the same problem and it was the aluminium sealing washer on the brass drain bolt on the bowl.

Switched it out to one from a spare carb but still needed to crank it tighter than normal but no more leak.

[speedlimit85]

Maybe but not likely.

Fuel level should be lower than top of bowl so if it's the float needles that are the culprit then it'll leak from the air box.

My "G" had the same problem and it was the aluminium sealing washer on the brass drain bolt on the bowl.

Switched it out to one from a spare carb but still needed to crank it tighter than normal but no more leak.

I replaced the washer with a copper one. Maybe that's the problem.

[skids]

I replaced the washer with a copper one. Maybe that's the problem.

You should be bale to see if it is leaking from the bowl plug. If it is actually overflowing the bowl, you can sometimes flush the fuel valve by draining the bowl, dropping the float, and refill by switching to prime. I would do that before taking the carb apart.

[speedlimit85]

You should be bale to see if it is leaking from the bowl plug. If it is actually overflowing the bowl, you can sometimes flush the fuel valve by draining the bowl, dropping the float, and refill by switching to prime. I would do that before taking the carb apart.

Okay. Thanks for the quik replies. I appreciate all the help.

[speedlimit85]

No more leaking!

I replaced a shot washer with a too thick one.

Partzilla part now.

[motoman]

My bike has fuel lines from the petcocks crossing to opposite carbs. I don't see T's or leaks from the lines.

True, your Standard doesn't have all those ratnest lines. Both petcocks have internal vacuum diaphrams that shut fuel off with engine shut off.

[skids]

No more leaking!

I replaced a shot washer with a too thick one.

Partzilla part now.

Eezy Peezy!