Jim,


Are you sure these will fit?

If the bolt is too short, it will not engage enough threads in the crankcase and this could prevent fully tightening the bolts (or could potentially destroy the threads...).
If they are too long (not in this case, at 10 mm length), they may run out of threads/depth, before the head is battened down tightly.

If DWR has one of the original bolts, he should measure them. If not, in liew of the originals, a technical supply house is better than paying $2.98 for eight bolts (he'll need two sets) and not being sure they will fit. He'll have more of a choice.

The MVVS .40 frame engines uses 3 mm x 14 mm thread length (17 mm total length).
The MVVS .21 frame engines uses 2.5 mm x 10 mm thread length (12.5 mm total length).

I think the OS.35 would need longer bolts, to take the head thickness + the distance between the head and the crankcase and still go 7.5 mm into the crankcase.

Bolts should engage to a depth of at lease 2.5 times the diameter of the thread - 7.5 mm in this case.