valve adjustment on 10k onan

[bench]

We have a 10k diesel Onan generator with just over 800 hours, It runs well but deposits black soot on ground at exhaust after a couple of hours Does this call for a valve adjustment? If so can anyone tell me what to expect to pay or how much time is the job takes. Thanks in advance.

[Mike Canter]

If you have the one with a Isuzu motor then it is required at 1000 hrs if it has the Kuboto motor then at 800 hrs. If it is a small deposit or blackening of the area right at the exhaust exit then that is normal for a diesel. If you don't see visible smoke after you first start it when it is cold and no visible smoke when it has warmed up then it is most likely OK. I adjusted my valves at 1000 hrs on my Isuzu motor and found them all at .012" vice the required .008". Since they were all evenly open then it was probably due to the break in and seating of parts.