I am rebuilding the starting engine for my D 2 5J 3742. I sleeved the cylinders as the pistons appeared to be in great shape. I installed the crank and it turned free. I installed the pistons and new rings and now there is a real drag on engine rotation. (The starting engine is on my work bench, not on the machine). The engine turns, but it takes a real effort. (This engine is rope started.)
Does anyone know the correct spec for the "piston to cylinder wall clearance" for these starting engines?
For the "ring gap" clearance?
Thanks in advance,
Dogger
the piston skirt clearance of a new piston should be .004" to .006"
the ring gap for both ring .012"to .020"
itzik
As a general point, when doing what you've done, forgetting to clean the carbon from the bottom of the piston ring grooves often makes the thing stiffen up on re-assembly. (with a good ring end gap clearance & skirt to bore clearance)