L 553 skid steer

[Ivan]

Last year I bought at auction a L 553 skid steer. I used it aroound here and theis winter I am rebuilding the engine in it. When I took the exhaust manifold off it had one cylinder almost plugged with carbon. What would cause this? I am having the valves ground and injectors checked before I put it back together Thanks

 

[Tazza]

I assume it is diesel, it could be a few things, bad injector, not enough load (prolonged idling) incorect vavle clearance.
There should be some carbon, but not enough to plug the exhaust ports