D&H 65 posted:John: Just my opinion, but the boiler shell needs to come off and check the gearbox cover to be sure it is tight and not letting the worm and driven gear get out of mesh.
I don't have this engine; maybe you get lucky and can access the geartrain from below, but I doubt it.
I agree although it’s hard to see why being on a shelf would create a gearbox issue of this kind even if the gear lubrication has gone solid or otherwise needs to be replaced. The gears are not engaging properly going forward but will mesh going back and that suggests to me they are not properly tightened in place.
I’m not sure but I think maybe the chuff on these engines is not generated by a magnet but electronically keyed to motor voltage/RPMs, which would account for why you are still hearing that effect.
