Engine running rough and popping w/o pto engaged

[IslandStyle]

2011 DC Classic 3372HP with Generac 33hp OHV1 V-twin gas 200+ hours. Engine pops and stutters at idle and while running without pto engaged. Seems to run better with pto engaged at higher rpm's. Also backfires when you shut it down from idle. Have checked the obvious and performed complete tune-up but still not luck solving the issue. Any ideas/suggestions would be greatly appreciated. Thanks

 

[reynoldston]

Have you checked valve adjustment?

 

[IslandStyle]

Thank you for your fast response sir! No I have not checked valve adjestment yet as I wasn't expecting that to be necessary at this point given low hours nor did I see it listed in the maintenance schedule. Would you expect that this could be the issue with a fairly new mower? I have another one with the same hours but no problems with it so far. Thanks again for your help and valuable time!

 

[motoman]

2011 DC Classic 3372HP with Generac 33hp OHV1 V-twin gas 200+ hours. Engine pops and stutters at idle and while running without pto engaged. Seems to run better with pto engaged at higher rpm's. Also backfires when you shut it down from idle. Have checked the obvious and performed complete tune-up but still not luck solving the issue. Any ideas/suggestions would be greatly appreciated. Thanks

I don't know what that engine is, but my Intek 24 did that with about 200 hours and it was a pushed valve guide which interfered with normal valve actuation. When you check the valve clearance look inside the valve springs on both valves at the guides. They should protrude from the head the same amount.

 

[IslandStyle]

yes sir, I will certainly do that. Thanks for sharing your experience. I'll be checking the valves tomorrow and let you know what I find. Many thanks!