Weeping Carb - on top

[GaryZ]

My 1985 VR is weeping gas out of a plug on the top of carb #1. The manual is not much help. The plug is about the size of a dime and has four very small slots around the perimeter (maybe used to remove?). You can see it in the picture below (its the shiny spot next to the #1 carb throat).

 

Can anyone help me with ideas on a fix?

[mbrood]

I believe that is the plug over the inlet screen (filter) and the fuel bowl, float needle seat. Item 40 in the micro fische. ( 41R-14118-01-00 $6.35 from Zanotti)

 

https://www.zanottimotor.com/shopping/pLookUp.php

[Snaggletooth]

Yep that is the plug for the hole that you use to change the needle seats. The net filter is just inside of it and the the needle seat is below that.

 

They are a bear to remove and replace. To get it out you need to drill part way into it and blind tap it to fit a small bolt. Then you can use a claw hammer to pry it up and out. If you chose to drill all the way through it plan on replacing the net fitler along with the plug.

 

They are a soft metal so you MAY be able to remove the carb rack and then supporting the bottoms of the carbs on a solid base be able to use a point punch and hit it hard enough to get it to expand a bit and reseat itself. No promises on that.

 

It would be my quess that the only reason it is leaking is the net filter is badly clogged or blocked. That is the only reason there would be any pressure (from the fuel pump) at that point.

 

If you open the carbs to the fuel bowl and spray carb cleaner through from the inside through the needle seat you should get a good flow from the fuel inlet pipe. If not, the net is clogged.

 

Go ahead, ask me how I know all this. LOL! I hate carbs!

 

Mike

[GaryZ]

Thanks Guys!

 

The local Yamaha shop has a mechanic that is very experienced with the Vmax. He says the plug is not available as a replacement and he suggested getting another carb. We discussed sealing the plug with epoxy and he seemed to think that would work. I have sealed Q-Jet carbs with epoxy and this seems to make sense to me. Any comments?

Edited August 12, 2009 by GaryZ

[mbrood]

Did you ask him about the part number supplied and the vendor pricing supplied?

 

I've heard several guys that have replaced the float seat... and you have to destroy this plug to get there...

[GaryZ]

mbrood: Did not ask about the part number that you found.

 

The function of the cap appears to be for plugging a hole left over from casting the body of the carb. It was much easier to simply epoxy the old cap. The epoxy is in place and seems to be sealing the gas leak. I will ride it around for a bit and re-check.

[mbrood]

"The function of the cap appears to be for plugging a hole left over from casting the body of the carb."

 

Um, no... as was said, it's the cap over the fuel screen and float needle seat...

It IS replaceable... but if epoxy works for you... so be it...

 

37 1FK-14190-15-00 NEEDLE VALVE ASSY 1

38 1J7-14994-00-00 NET, FILTER 1

39 1FK-14147-00-00 O-RING 1

40 41R-14118-01-00 CAP

 

http://www.bergall.org/temp/venture/floatplug.jpg

[Condor]

Dang that is one dirty looking engine. Time for three of four cans of carb cleaner....

[GaryZ]

Dang that is one dirty looking engine. Time for three of four cans of carb cleaner....

 

You noticed!

I was a bit surprised myself when I pulled off the air cleaner.

Although the grime made it easy to find the fuel leak!

I have had the bike for a year and thought I had cleaned it up pretty good.

It had 61,000+ miles on it when I got it, 63,000+ now.

[GaryZ]

"The function of the cap appears to be for plugging a hole left over from casting the body of the carb."

 

Um, no... as was said, it's the cap over the fuel screen and float needle seat...

It IS replaceable... but if epoxy works for you... so be it...

 

Thanks for the drawing and part numbers. I may need them.

[Venturous Randy]

I have found that to seal anything that is gasoline related, I use "Seals All". It works very good, is resistant to gas and seems to be readily available.

RandyA

[jfman]

I have the exact same problem on one of my carbs. It weeps fuel from this plug on the leaft rear carb.

 

I am considering tapping on it using a small socket as a "punch"

 

Maybe that will seat it correctly.

[Prairiehammer]

I have the exact same problem on one of my carbs. It weeps fuel from this plug on the leaft rear carb.

 

I am considering tapping on it using a small socket as a "punch"

 

Maybe that will seat it correctly.

 

That plug is the cap for the float valve seat with net filter. The cap has an O-ring.

Looking at the pic, it appears that the cap has been replaced (the original cap was staked into the carb body, but the new one has not been staked to secure it).

[jfman]

Thank you for this info.

 

I used a photo from another set of carbs I am working on because I was too lazy to go get an actual photo from the bike in the garage.

 

I guess there is no point tapping on it as the culprit is probably the little oring.

 

These carbs habe been off the bike for 4 years. I wonder if there is a chance the oring will swell and the leak fix itself.

 

I had that happen on another bike that had been sitting. It leaked fuel from a injector connector for a short while then it quit as the seal swelled up.

Edited December 1, 2019 by jfman

[jfman]

I was a bad boy. I tapped it and it sunk in about 1mm and it quit leaking. Gonna add JB weld on top just to be certain.

[campfire12]

I'll secound the seal all. Good product, got some at O'rilleys auto parts.

[saddlebum]

When I rebuilt my carbs I made up a tool that I could just pop it out from the inside. I made it in such a way that it allowed me to drive it out even though I had to drive at an angle without harming the crab body or needle seat. Than I just replaced the o-ring on it put it back in place and peened it with a center punch to lock it in. If I manage to find that tool in all my clutter I will post a pic.