leaking carbs

I'm getting a gas drip on the bottom cover of the carbs, it looks like a leak between the middle carbs, so off they come (again). I was hoping that maybe it was just a loose screw on one of the float bowls, but no such luck. The connecting pipe is sliding back and forth, and I'm not sure that its supposed to do that, and it looks like thats where the gas was leaking from. I know there's an o-ring on each side, probably a very old,dried out, and shrunken o-ring. Breaking apart the carbs to replace an o-rings seems a bit daunting. Is there an easier way to plug this? Does anyone know of some miracle sealant that I can smear on it?

 

Looks like all you'll probably have to do is replace the carb float bowl gasket. Also make sure that your petcock (the thing on the bottom of the gas tank is not on Prime) made this mistake once and my carbs started leaking. I think Yamaha stop making the carb float bowl gaskets but K & L still makes them.

 

I already replaced the float bowl gasket, that's why I thought maybe I just hadn't tightened the float bowl screws. It didn't start leaking until it was running with the petcock in the "on" position. Its tough to tell where it was leaking with carbs off, but it looks like maybe it was coming out at the connecting pipe, running along the bowl and dripping onto the bottom cover. I guess the connecting pipe sliding back and forth (easily) between the middle carbs is what is making me think the o-rings are gone. Is this normal?

 

I've had my carbs off and on and off and know it's a pain... but it needs to be done.

I had a stuck float which caused the fuel to flow out the "filter" side of the carb. Fixed that problem and in trying to "sync" my carbs found I needed to remove them once more to check/replace the orings on my butterfly valve shafts.

While apart I checked the orings on the fuel supply line between carbs and they are cracked and need replacing also. I got those orings today and need to get back in the garage to reassemble the carbs.

From my experience if the connecting pipe your refering to is the brass fuel line from carb to carb you should replace the orings and while at it replace the shaft seals on the butterfly valve shafts.

You can check your outer two seals by removing the "e" clip and plastic washer to reveal the shaft seal. Take a close look and judge if yours are any good!

See my pic gallery for pics of my old seals.

 

The o-rings on the filler pipes are still available from Yamaha.
A good investment.
Another tip, when replacing them dab a little oil on the rings before you push them into the carbs, makes it a whole lot easier.
I know someone here has ordered a set of the shaft seals and should have them for sale soon.

Nachoman

 

I know this is hindsight - because I did the EXACT same thing!

After I took my carburetors off of the rail - I took them into my local shop. They told me that was a very bad idea, and they said they NEVER take the carbs off of the rail unless they have to.

This is because of the problem you just encountered - they said that the majority of the time, the orings in the fuel junctions begin to leak, and then you have to take them off of the rail AGAIN!

So - for future reference, for those of you searching - leave the carbs on the rails when you clean them, and you could probably avoid this situation. And you would have less synching to do when you put them back on the bike.