Sticky float 50's Cub w/ replacement carb...Zenith?

Tue May 14, 2013 2:15 pm

Short of replacing float pin & seat any quick fix for sticky float? How to ID replacement carb for new carb parts? Think carb same as used on fork lifts...

Re: Sticky float 50's Cub w/ replacement carb...Zenith?

Tue May 14, 2013 4:19 pm

Troubleshoot the problem before throwing money at it.

Look for the "Zenith Bendix" or "IH" logo on the carburetor. Posting a picture of the carburetor will help identify it.

Determine why the "float is sticking" before replacing parts. For instance, are the pontoons hitting the carburetor casting or is the float hinge binding or are moving parts gummy due to decades of gasoline residue? Is it sticking open or closed? The root of problem may have nothing at all to do with the float or the needle/cage, the carburetor may just need a good cleaning.

Re: Sticky float 50's Cub w/ replacement carb...Zenith?

Wed May 15, 2013 9:32 am

I agree with Carl. Diagnose the problem first. Replacing good parts with a new item makes little sense, especially if the carb is simply dirty from contaminated fuel. As Carl said, please post a pic of the carb so it can be identified.

Btw, G'day to you and your Cub :D We have lots of resources available to our members so I suggest that you follow the links below and spend a little time familiarizing yourself with those resources. You might want to find out what year your Cub is - Cub FAQ's #1 on ATIS - #13 or you may want to read up on Carl's excellent articles on the Cub IH 3/4" Updraft Carburetor - Lurker Carl's Cub Carb Fixes. You may also wish to inspect the complete fuel circuit - although this is an upgrade to the circuit - it does indicate the things to look for and repair - How To Upgrade A Cub Fuel System

Image to Farmallcub.com :big smile: Forum Family. And you have come to the right place for all things Cub related. If you click on the Site Rules, Regulations, & Important Information, it will point you to :arrow: the Welcome Wagon wherein you will find links to many useful sites and topics. One of which is the Cub Manual Server. Enjoy!.

Re: Sticky float 50's Cub w/ replacement carb...Zenith?

Wed May 15, 2013 4:49 pm

I will be watching this, my IH carb is the same way. won't seat good and leaks fuel on the floor and sometimes tractor dies because float is stuck and letting no fuel in.

Re: Sticky float 50's Cub w/ replacement carb...Zenith?

Thu May 16, 2013 11:39 am

Take the carb off. Roll it over gently, while listening carefully. You should hear a "tink" as the float moves from one extreme to the other. That means the float is moving.

In all likelihood, it's not the float that is stuck. Most likely you have the float height setting off, or you have a needle that isn't seating.

If you used the Tractor Supply (A&I) rebuild kit for the IH carb, the needle/seat included is completely *WRONG*. It doesn't fit without bending the living daylights out of the float, and once you start messing around with the float that much you can get yourself into trouble real quick.

Carburetors can be frustrating, but you have to stick with it and keep taking them off and fiddling with them until they work right.

Re: Sticky float 50's Cub w/ replacement carb...Zenith?

Thu May 16, 2013 12:53 pm

Also, just to throw a little more complexity in this. If the needle tip is Viton, they have been known to get gummy at times because of the Ethanol in the fuel. That could be causing the needle valve to stick. This is for IH carb...don't know if there is a viton tipped needle for Zenith carbs.

Re: Sticky float 50's Cub w/ replacement carb...Zenith?

Thu May 16, 2013 8:50 pm

I fought with my carburetor for a long time. It would leak when I shut the engine off. I cleaned the carb out several times, and replace the needle and seat with new parts from TM. Finally, it started blowing black smoke even at full throttle, so I took the carb off again to check the needle and seat, and found the float half fulll of gas. I replaced the float with one from a spare carb, and it hasn't leaked a drop since. It runs like a whole new machine. Just something to check.
glenn