carb adjustment question

Fri Dec 28, 2007 6:46 pm

To start my cub lo-boy I must pull the choke and while pulling on the starter push the choke back in. If I leave the choke out while running the starter or in while running the starter it won't fire. Question is do you think the carburator settings are too rich, and which screw do I turn and how much? Otherwise once the engine warms it seems to run good. No trouble mowing in 2nd with my woods 59.

Fri Dec 28, 2007 7:08 pm

Sounds ok to me. The idea of the choke is to give it a little extra gas to get it running.

Fri Dec 28, 2007 7:09 pm

Every one of my cubs has it's own preferred method of starting. Some you can choke, some you can't. As long as it runs right after starting just get used to how it wants to be started.

Fri Dec 28, 2007 7:13 pm

Tough one to answer. Your starting procedure is just about 100% like mine. Throttle lever about 2/3rds open. Full choke during first engine revolution or two, feather choke in a bit, engine starts. Then choke about 3/4 open for a minute or so as the engine warms up - then choke full off.

The IH carburator only has an idle adjusting screw. Adjustment. Start and warm engine. Engine at idle. Slowly turn the idle adjusting screw in about 1/8 turn, wait a moment to see how the engine runs. If engine conditions improves another 1/8 turn in. Engine condition worse back out a bit. You are seeking the idle screw position where the engine operates smoothly - at it's best at low engine RPMs.

It takes longer to explain than to do the adjustment.

If the Zenith carb with two adjustment screws. Adjust the idle screw first then the main jet.

Fri Dec 28, 2007 10:28 pm

Funny-on the new backhoe Cub, I had to start it with the choke in, then pull it out top keep it running-I was thinking, "Needs a total carb rebuild", but then I toticed that the choke lever on the carb was uposide down, and so pulling the rod out opened the choke, and pushing it in choked it.

Not really anything to do with your question, but it made me think of it-and it taught me(again) to not take ANYTHING for granted on these old beasts.

Sat Dec 29, 2007 3:50 am

Bigdog wrote:Every one of my cubs has it's own preferred method of starting. Some you can choke, some you can't. As long as it runs right after starting just get used to how it wants to be started.


Boy, ain't that the truth Bigdog. Of our 6 running tractors(only one cub), they all start different. Heck, that's part of the fun of getting a new tractor, learning its starting habbit. Sometimes it can take awhile.