Shaft lengths?

[tbird175]

I bought my 1978 175 HP Blackmaxx new for my boat in 1978. It is a 20" shaft or long shaft. I am now looking for another boat for the engine. I looked at 3 different ones this week. They all have a taller transoms than my boat. They are 23" to 25". Mine is 20" top of transom to bottom. I have a copy of an OEM Merc. manual for my engine that only shows 15" and 20" shafts. Are there other length shafts available? Would my engine work on a taller transom?

 

[usskydvr]

Re: Shaft lengths?

15" = short shaft
20" = long shaft
25" = extra long shaft ( I think 86 was the first year for these)

 

[Blevins]

Re: Shaft lengths?

MOST never boats use a 25" shaft. I know as soon as i post this someone is going to jump down my throat but keep in mind i said MOST. That being said you can find boats mainly before the late 80 or early 90's that are designed for 20'' shafts. The motor would "work" persay but if the boat is designed for a 25" shaft you will see little acceleration and awful fuel economy. Find boats that you like and contact the manufacturer to find out what the boat was designed for.

 

[tbird175]

Re: Shaft lengths?

Thanks for the help