Engine mount bolt reply

 This is a reply to my question in the Beta engine forum about the engine mount bolt.


"Hello Chip,

It looks like you have created custom mounts. The three socket cap bolts in the photo are factory bolts. The factory bolts in the photo are 10mm bolts with 1.25mm threads, grade 12.9. This is a high tensile bolt, normally available in a socket head style only.

The tap size would be the same, 10mm with 1.25mm thread.

I cannot identify the hex head bolt as it is not factory supplied.

I would carefully chase the threads and replace with a 10mm bolt with 1.25mm threads, grade 12.9. Check your depth.

I suggest that you find a better place to ground for lightning protection. It does not make any sense to try and direct a lightning bolt through your valuable new engine. A lightning strike through your engine will most likely damage it.

Be aware that Beta Marine supplies a flex coupling with the Beta 38. This flex coupling electrically isolates the engine from the propeller shaft.
If you used this flex coupling you no longer have a path to ground via the propeller shaft. This applies to both lightning protection and shore power grounding.
A hull mounted ground plate or other such mass of metal would be better suited for a lightning ground."