In over my head again *Updates*

[sano888]

*Update* Everything went together fine. Started mowing and checking belt for wear. About 45 minutes into it I noticed some wear. Idler pulley seemed to be bouncing around quite a bit from the get-go but the whole deck seemed to be shaking after 45 minutes. Could it be the idler arm spring? Noticeable drop in power when PTO is turned on and also when mowing uphill. Think I might check to make sure both cylinders are firing,

 

[Auto Doc's]

This favors blades out of balance or very worn spindle bearings. The tensioner idler will jump back and forth, that is normal.

As for a cylinder dropping out, that would usually reduce the power so much it would not be able to cut and drive at the same time.

Verify your plugs are correct and the gap is set.