Re: Can these model Mercury motors be converted to electric start?
Laddies is right on. The Mark 30 powerhead is essentially a sleeved down Mark 55 (eventually evolved into the 44-cube 50hp Mercs built for a generation). As such, it shares much with the Mark 55 powerheads and you can use the electric start parts off of one (1956 and later models). You can get parts lists, etc. from Grubb's at
www.oldmercs.com.
The Mark 25 had an electric start version (Mark 25E) but they are rare and the electric starters were unique to the model, so there isn't much of an outside source for them. Plus there's the whole cowling issue - another part unique to the Mark 25E.
I'm not sure if the Mark 28 was ever offered as an electric start model. I've never seen one and I don't see it listed on the oldmercs.com site. However, I did see a white Super Hurricane (Mark 28, Merc 200, Merc 250) powerhead once with a ring gear flywheel, so it stands to reason that one may have been offered as an accessory.
- Scott