Carburetor Rebuild

[Tractor Rod]

Help please…..I followed all of your directions and ordered carb kits from Morgan and after a complete rebuild plus new floats in both of my IH carbs they both leak out of the air intake. I corrected a sight warp in both and per everyone’s suggestion I didn’t replace the main jet and left the original ones in.

I’m lost as to what I have done wrong for both carbs to leak a pretty steady stream of gas out of the air intake……any thoughts will be much appreciated!

Thanks…..

[tst]

either the float height is off or bad float, or the needle/seat is bypassing, start by making sure float is set correctly

[Bill V in Md]

Does the tractor fire and start right up?

[Tractor Rod]

Thanks and I’ll check both those items and also it doesn’t start right up.

[Bill V in Md]

It the tractor does not start right away, the excess fuel drains back down and out of the carburetor through the drip hole. That is normal.

[Tractor Rod]

The gas is running out in a steady stream and the cub won’t start. I’ll double check the float since I put both new ones in.
Thanks.

[Don McCombs]

[52DAVE]

When I had a similar problem I found out that the seat for the needle valve wasn't sealing quite enough. I don't know if the fiber seal was a little to thin or not but I had to tighten it very tight to get it to stop leaking.

[Jim Becker]

You may have a problem with the float not freely pivoting. Drag may keep it from completely closing the needle valve. It could have a problem rubbing on the side of the bowl and/or too snug of a fit between the two little posts that hold the float pivot pin. Check for this by taking the fully assembled carburetor and slowly turning it back and forth between upright and bottom side up. You should be able to hear the float move between open and closed.

[Gary Dotson]

A few years back, there were some aftermarket floats that were just a tick too long. They would rub the end of the float chamber and not close. Also, look at the float chamber, on the outside, in case someone, in the past, used a hammer on it. If it’s dented in, it may also interfere with float movement.

[tractorjunky]

Take a look at the mating surfaces where the needle and fuel jet gasket goes. Mine where pitted and the only way I could get it to stop leaking was to use a thread sealant.

Pitted gasket surface

After a bench test for a week, no leaks.

I used this same set-up to test the carb and the sediment bowl.

Fuel leak test set-up