Cub Cadet GT2550 Running on One Cylinder
 

My Cub Cadet GT2550 (with only 126 hours of running time on it) is now running only on one cylinder. My son changed the Spark Plugs -- no improvement. He thinks that one spark plug wire may be bad, and needs to be replaced. Could the problem be anything else?

(Needless to say, the mower lacks power but can still mow 6"-high grass if one goes slowly).

It could also be a bad ignition coil, or an intake leak. get a $10 spark tester at Horrible Freight, put it on and check the spark first. If that turns out good, while engine is cold, start it spray carb cleaner around carb base, listen for engine to change sound (rev up), if not there try spraying it between valve cover and fan shroud and listen there......this is where my Kohler v-twinn showed me it had an intake manifold leak.

Mark

It's highly doubtful that it's an intake leak. That would not cause one cylinder to misfire. It would affect BOTH. It could be the coil. The wires are not replaceable. They are made on the coil. You sure it's a misfire? Didn't break a rod did you? Or perhaps lose/bend a pushrod? I'd check for spark first. If you find it has spark, the do a compression check. Please, stop mowing with it. If you continue to run it you will only damage the motor worse.

are you sure it's only running on 1 cylinder? Those Kohler Commands are real picky about having a clean air filter and pre-cleaner. On mine if it is the least bit dirty it'll be way underpowered, run funny, and even die under load going uphill.

The reason that we know that it's running on one cylinder, is that when you unplug the right cylinder's spark plug wire (when the motor is running), nothing happens. When one unplugs the LEFT spark plug wire (when the motor is running), the entire engine dies.

Also, there is the smell of unburnt fuel coming out of the exhaust pipe.

We're going to get a new ignition coil from the local (Spokane) Cub Cadet dealer, and see what happens. Thanks for everyone's assistance!

Just because you pull the plug wire and it dies doesn't mean it's ignition. Just tells you which cylinder. You need to find out if you have SPARK on the dead cylinder before you replace the coil.