20" shaft to 25" ???

C

cyote

Cadet
Joined
Nov 12, 2007
Messages
15
I have a 175 black max that I slug a rod in while getting itvsummer ready. I have it on a 20 prostar mastercraft. I know someone who is selling a 225 with a 25" shaft and mine has. A 20" shaft . My question is how would this effect the performance of my boat with the shaft being 5" longer?
 
Frank Acampora

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: 20" shaft to 25" ???

It will negatively affect performance with the prop and exhaust being buried 5 inches deeper in the water and the extra drag of 5 inches more of the midleg in the water. Not to mention that the spray off the leg will most likely climb it and dump into the splashwell.

Buy the engine and either build up the transom 5 inches or better yet, buy a jackplate and raise the engine 5 inches or so---whatever gives the best performance.
 
C

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,158
Re: 20" shaft to 25" ???

Some of the 25" Mercs have a 5" spacer. If your gearcase is good, and compatable with the 225, and it has the spacer, you should be able to convert it to a 20" length.

You might ask the questions on the merc forum
 
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