Wisconsin vh4d skipping/missing

[MAK]

The engine in the Bobcat 610 I just got is running rough. The #2 cylinder seems to be the source. When I remove the plug wire to that cylinder it seems to run smoothly... That plug was wet but otherwise looked new. That cylinder and two others have a compression of 90lbs. The #4 was about 85lbs. Distributor cap looks new. Plug wires are old but but I swapped wires and the problem remained with the cylinder and did not follow the wire. I swapped the plugs and problem remained and did not follow the plug. Ideas? What am I missing? Thanks

 

[6brnorma]

I had to check with Continental this morning on some other unrelated issues so I asked them to verify compression ratings. They told me exactly what I had noted in my manual. A good running engine should be up around 120……they don't like them to fall below 100 and 80 is definitely low. Most importantly is balance of compression between cylinders……I've had a couple that had all 85s and ran for quite a while longer. You have low/very low compression but I'd still look or electrical issues before I gave up on the engine entirely.

 

[MAK]

I had to check with Continental this morning on some other unrelated issues so I asked them to verify compression ratings. They told me exactly what I had noted in my manual. A good running engine should be up around 120……they don't like them to fall below 100 and 80 is definitely low. Most importantly is balance of compression between cylinders……I've had a couple that had all 85s and ran for quite a while longer. You have low/very low compression but I'd still look or electrical issues before I gave up on the engine entirely.

Ouch. I was thinking my compression was good. Didn't realize it was supposed to be around 120. Not what I wanted to hear but I appreciate you checking on that and responding. Thanks