Correct motor shaft length

[mnwnvc]

I have a 69 20 ft. SeaCraft CC Transom measures 21 inches from motor support to keel. Would a 20 inch shaft motor be correct for this boat?

[GroveGuy]

Welcome to the site!

I would Guess that you would be OK with a 20" shaft engine with that transom. Hopefully more knowledgable opinions than I will chime in.

What would be a factor in your decision is the condition of your existing transom.

Is it original or rebuilt? What condition?

When I was engine shopping to hang on my original 20" transom, I knew that rebuilding and raising it to 25" was a futrure possibility. With this in mind, I acquired a 25" shaft engine and used a jack plate to properly mount it on a 20" transom. This setup worked great, but. . .sure enough, a 35 year old transom is living on borrowed time and the rebuild day could not be put off any longer. I rebuilt my transom to 25'" and happily the same power fit back on like a glove.
Hope this helps.

Good luck with your decision

[BigLew]

If I am incorrect about this someone will undoubtedly chime in, but, I believe that the measurement you want is the distance between the top of the cavitation plate and the highest point INSIDE of the engine mount bracket where the top of the transom fits up into the mounting bracket on the engine.

Fom what you describe, I would guess that a 20 inch shaft would be correct. There are INDUSTRY standards regarding shaft length, it's just that we need to know the two points on the engine to measure from to determine what the shaft length of a particular engine is.

Good Luck and be well.

[BigLew]

PS to post above.

Welcome aboard to what is undoubtedly one of the best "user forums" on the net. Learn and share is the rule!

[hermco]

20" shaft length is correct.

[mnwnvc]

Thanks to everyone for their advice. The transom is already rebuilt so I will be sticking with the 20 inch shaft. I am planning on using a Optimax 115 on this 20 foot boat. Does anyone have a prop recommendation for this combo?