Please Help with Carb!!!

Mon Aug 03, 2009 5:41 pm

I have a 1963(I think) cub 154 lowboy that I was having carb trouble with. It was very hard to crank and would run only with the choke about half out. I took the carb off, took apart, soaked overnite and blew out and reassembled with new gaskets. The dang thing will not crank at all. If you choke it, it pours gas out and seeps out around the choke shaft. Any help would be GREATLY appreciated. Thanks

Re: Please Help with Carb!!!

Mon Aug 03, 2009 5:53 pm

Welcome to the Forum. If the carb is completely clean, check the screen in the inlet line and the screen at the fuel bowl. If all is good and still having issues, check for leaks on the carb letting it suck air. Make sure the breather tubes are installed and tight and spray aerosol ether or unlit propane bottle around the carb, if a leak is present, the engine will suck up some of the ether or propane and cause the RPM's to increase. Could be the top to bottom gasket, the manifold gasket or the shaft seals.
Good luck and let us know the results. Also, your tractor is not a '63. IH didn't start building the 154s until '68. Let us know the SN and we'll tell you the year.

Re: Please Help with Carb!!!

Mon Aug 03, 2009 6:48 pm

Curious. What do you mean "engine will not crank"? Starter/generator will not turn the engine over?

If you mean it won't start - have you investigate an ignition problem? When was the last 100% engine tune up?

Re: Please Help with Carb!!!

Mon Aug 03, 2009 7:01 pm

Thanks, when I say it won't crank I mean it won't run, thats southGeorgia slang. Its getting fire at the plugs. It was seeping fuel at the carb to intake gasket but I got that stopped. I'll have to take it off and check the top to bottom mating without the gasket. How tight does the throttle shaft supposed to be? This one has a good bit of play. Also, the serial number is almost impossible to read, is there any other way to determine year Model? Thanks Again

Re: Please Help with Carb!!!

Mon Aug 03, 2009 7:04 pm

dk47 there any other way to determine year Model?

Posting a photo may help.

Re: Please Help with Carb!!!

Mon Aug 03, 2009 7:08 pm

The throttle shaft should not flop around when the carb is moved. It should be relatively stiff, but not binding. The seals hold the shaft pretty tight.

If you let us know the engine SN, or a sampling of the cast codes, we can give you the year of manufacture. Engine SN location:
Here are the cast code locations:
Of course yours won't have all the parts in the photos, but the engine, transmission and finals are the same.

Re: Please Help with Carb!!!

Thu Aug 06, 2009 10:27 am

Sounds light the float in your carb is sticking. If you are getting fuel , you can rule out that something plugged up. I had the same problem with my carb. It would always leak when it was parked. It would run very rich and was tricky to start. After taking it apart about a dozen times, I finally found the problem with help of a friend.
When you have the carb off, and still assembled, gently shake the carb straight up and down. You should be able to hear the float go up and down. If you can hear it, now gently turn the carb upside down and back again. Can you hear the float? When I did this on mine, if you listened very carefully, you could hear the needle hit its seat but not the float. I took it apart again and found the two post that hold the float were too tight. I gound a very small amount off of the brass float at the piot point and put it back together and it has been working great ever since. This is my two cents worth. Ted