New owner of a Cub 1450 - rough idle
 

Hello,

I cut the lawn for the 2nd time yesterday, and the Kohler is now idling rough. It was fine, perfect in fact the first mow.

It runs fine at higher throttle.

The gas is only 87 octane. I plan to use new, better gas next time.

Should the carb be re-built?

What octane should I use? Octane booster?

It seems to be running pretty hot as well. Not sure if this is normal.

Thanks a lot for any help,

Mike Angelini
PA

If it is running hot, make sure the cooling fins are clean...take off all of the engine tin and see. Make sure the timing is set correctly and the carb isn't set too lean. Any or all of those things can cause it to run hot.

There is no reason to use anything higher than 87 octane in these low-compression engines...anything higher and you're just throwing your money away.

First thing I would do is adjust low speed air/fuel mixture screw. Sometimes the vibration from the engine will move the air/fuel mixture screw. Next thing I would do(if you haven't already) is check the air filter and replace as needed. Same thing with the sparkplug. Autolite sparkplug works better than a champion plug.

In the tech section on thie site there is a Kohler engine manual you can download or just look at. The manual say 87 octane gas with 10% or less ethanol is ok to use. That is what I run in all but one of my Cub Cadets. That Cub Cadet must run 110 octane gas because the pulling class rules require it. I will run 89 octane in it when I'm not pulling with that group. It feels like it makes more horse power on 89 octane.

I would go to a 30 day gas schedule. I try to buy enough gas for my small engines to last 30 days. When the gas is 30 days old I add the fuel left in my small engine fuel container to my truck. I recomend you add a fuel stablizer to your storage fuel container before you fill the container with gas. Sta-Bil and one from Briggs and Straton are 2 good ones to use. Shake you fuel container before you add fuel to your small engine. The additives in the gas will seperate and could cause some problems. Store your gas in a sealed container.