Float

[Luke470]

After much searching and angst and frustration and tons of good advice from all of you I tried lightly tapping on the fuel bowl to see if my starting problem was a stuck float. Sure enough! I pulled the starter and she fired up and ran like the champ she is-this was Friday. Went out yesterday and she started right up again!

Today not so much same issues as before. It tries to start it wants to but just won't go and fuel starts dripping out the drain. I tried tapping the bowl again with no luck.

Any suggestions other than a carb rebuild? There is the metering jet that comes out the side of the fuel bowl which is the metering jet but then there is a bolt at the bottom of the bowl. What is that?

Thanks!!

[Don McCombs]

Pipe plug at the bottom of the bowl is the bowl drain. I would advise that you stop tapping on the carburetor and adjust the float properly. Be careful of the idle tube when you separate the two halves of the carb. Clean everything up good, while you're in there.

[Barnyard]

I would advise that you stop tapping on the carburetor and adjust the float properly.

I totally agree with Don. These carbs are made of soft metal and after a few too many taps that bowl will be out of shape and will jam your float. Fix it right while you can. It is much harder to repair after you have deformed the bowl.

[John *.?-!.* cub owner]

The float itself sticking may not be your problem, but the float valve above it sticking.

[FarmallCubby1949]

Thanks Don for posting that diagram on here. That should be very helpful to me when me and my dad rebuild the carb. I'm having the same issue as Luke with mine. I get the same result when I try to satart mine. I did't tap the float bowl for the same reasons that Don and Barnyard mentioned.

[bythepond88]

Before you start pulling the carb off, put a small bowl under the carb, pull that plug at the bottom of the bowl, and turn on the gas at the tank to see if you are getting fuel into the carb.

fuel starts dripping out the drain

. This tells me that the float is not sticking, because if it were, there would be no fuel to leak.

[LeoM]

I just bought my first cub last weekend. My post is the 1 just previous to yours. I don't know how long it sat without running but the gas had turned to a brown varnish like goop. After installing a new battery and starter solenoid I tried to fire it up. The engine spun easily but did not start. I gave it a shot of starting fluid and it came to life. I ran it a few seconds on starting fluid just to hear it and it purrs like a kitten. I pulled the carbuerator and found the bowl dry. I cleaned it and when I reassembled it the floats did not move freely. After a more careful inspection I found the rubber cone tip on the bowl inlet needle valve was partially pulled out of the metal bar about 1/16". This effectively closed the passage and did not allow any travel of the needle valve. Normally I would expect the tip of the needle to be a smooth cone from metal rod all the way to the rubber tip I am waiting for a rebuild kit now.
Leo

[Don McCombs]

Leo,

This may seem obvious, but did you thoroughly clean the brown goop out of the ENTIRE fuel system? Tank, sediment bowl, fuel line, carburetor? Second question is, did you prime the engine oil pump before attempting to start? If not, prime it before attempting another start.

[LeoM]

Yes. Flushed the tank thoroughly and put in about 4 gal. of Non-Ethanol gas. Also installed a new in-line filter. I let about a quart of the new gas flow throught the new filter and verified gas flow to the carbuerator inlet connection.

[Bob McCarty]

The OEM needle is all steel with a brass seat. They are still available but expensive. ALL the aftermarket ones that I have seen have the rubber/Viton tip. They usually are okay, but sometimes stick.

Bob

[Bus Driver]

It would be nice to be able to use a petcock in the bowl drain plug position. But the petcock would protrude inside and push the float up. Not good. When the bowl drain plug is removed and reinstalled too much, the threads in the bowl may fail.

[challenger]

As others have noted, the problem most often occurs with the viton or neoprene tipped needle that gets stuck in the closed position when the tractor has not been run for a period of time, like overnight. Ethonal may contribute to this sticking problem. If the needle does not have a head designed into it with a fine wire linking it to the float arm, it can stick in the closed position and not follow the float arm down as the float lowers in the carburetor bowl. One thing you can do to prevent this from happening is when you shut the tractor down shut the gas off first and run the engine until it runs out of gas. This will insure that the needle rests in the open position. I do not know if there are after market kits for the IH carb that come with a needle that has a head designed into it with wire linkage. I have a Cub with a Zenith carb that had this problem. It had a needle with a head but no linkage. I designed linkage (you can find examples of the fine wire linkage on the internet by searching carburetor needle valves) using fine steel wire taken from a broken guitar E string, but you will first need a needle with a head on it.

[Barnyard]

Yes. Flushed the tank thoroughly and put in about 4 gal. of Non-Ethanol gas. Also installed a new in-line filter. I let about a quart of the new gas flow throught the new filter and verified gas flow to the carbuerator inlet connection.

But did you prime the engine oil pump as Don mentioned?

[LeoM]

I missed his recommendation. How do you prime the oil pump?

[staninlowerAL]

Try a search for "prime oil pump", there are several posts on the subject and multiple ways to do it. I prefer to remove the oil filter cover and fill the hole on the side with engine oil. Might take several times, then turn the engine with a hand crank
or starter until oil bleeds from this fill hole while turning, then replace the cover and start up, watch for oil pressure on the gage. Stan