I was in the shop yesterday attempting to rebuild a pair of Cat 10 Ensign Carbs. I have a consistent problem with both that is puzzling me. The first carb came off a poorly running Ten but was not exhibiting the problem noted below and second was the rebuilding of a carb for an advanced swap. Both carbs seem to be getting too much gas and are leaking it out the butterfly and breathers on the bottom of the carbs. I am fairly certain it is not the float because when I remove the float and top of the carb the bowl is dry and gas has drained out. I have a gasket on the bottom and top of the venturi tube which I am fairly certain is making contain (but would not stake my life on it). Looking for advise from the BB members who may have encountered such a problem and how they resolved it.



Greg

Well, here is is my experience. The ensign carb on my PV-15 does the same thing. I'm told the float is sticking. I get gas running out the bottm of the carb and it makes a mess.. I tap the side of the carb and is usually frees it up and it starts.

The carb has been completley rebuilt and it still does it. I'm on my second flloat which has helped the situation.

I have another tractor with the same type carb and I never have any trouble with it.

Dunefanatic,

Your float can be just fine...but if the needle and seat are bad, it will always leak fuel out the bottom of the carburetor. Mine does, but not real bad. I could not find a needle and seat to match mine (non standard) so I had to try and hone the surfaces to true them up. I was close but not exact. I have just gotten use to cutting off the fuel and letting the engine burn off what is in the carburetor to shut down.

If those gaskets are not EXACT (top and bottom of venturi tube) fuel will leak by the bottom one too. But usually if fuel leaks by...the tractor will not start either. It needs to make a good seal for any air or fuel to atomize in that chamber. You know you have it right when you assemble the top and bottom halves of the carburetor, the top cover should have a tiny gap between it and the bowl gasket. When you put the screws in and tighten them up, it will pull everything tight! Over time those gaskets can dry out and shrink.

Pat,

I definately hear what you are saying about bowl lid and a gap which is exactly what I had so I knew I had compression on the venturi gaskets. The couple things that bother me are needle not shutting off so I will attempt a bit of buffing of the needle face to clean up but it is a rubber face.

What I am still perplexed by is when I remove the bowl lid there is no fuel at all in the bowl and there is a cast ring (moate) around the venturi tube that should retain some fuel. This is the thing that perplexes me, a bowl that is wet but with no standing fuel becasue it has all drained out. I am tempted to place a extremely small bead of RTV on the bottom gasket where the venturi seats to see if this slows or stops the lareg fuel leak.

I have many other Tens with Ensign carbs that do not leak so I know I am just doing something wrong and it's annoying as hell!

Greg

Greg,
If you figure it out, let me know as I have a High Ten doing the exact same thing.

Greg
I am watching this thread closley for future referance, I have found a product called seal all that comes in a yellow tube with red trim, its cheap and will stand up to gas, I think better than rtv in a gas application, usually available in autoparts and hardwares. Looks and acts like clear contact cement.

Is this the stuff that claims to work on leaky fuel tanks? I haven't used it in a long time but I remember it being impervious to gasoline.
drujinin

My Ten has the opposite problem. It runs fine under load and at higher rpms, but I have to leave the choke on 3/4 or so to keep it from surging at an idle. Any suggestions before I take it apart. The idle mixture screw doesn't seem to have much of an effect.
Thanks, Jim

Jim,
These carbs were not exactly top notch for their day. The screws on my carbs do not do a whole lot either. I sure have seen a lot of 10's and PV 15's with some other make of carb modified to work on them.

Greg,

It sounds like fuel is leaking past the lower gasket or maybe through a crack??

Try a sealing agent that is impervious to fuel as noted in these posts. If that doesn't work, there must be a crack some where in that venturi tube or near the base of it, in the bowl itself.

Mine holds fuel...it just can not completely stop it from entering the bowl past the needle and seat.

Jim D4&6,

The idle screw is nearly useless, but I do have mine turned in almost all the way. It might be backed out .75 to 1 turn at the most. This should make it extremely rich...but it runs just fine. The idle mixture screw is an air bleed so it works the opposite as the main mixture screw. Mine use to hunt at idle but when I found my magneto coupling had a lot of play in it, I fixed it, reset the timing and the hunting went away. I suspect at idle the timing was getting so late that the engine had a hard time trying to maintain a constant rpm.