Combining motors?

mamm7215

Petty Officer 2nd Class
Joined
Apr 28, 2010
Messages
184
I just bought a 17.5' runabout a couple of months ago not knowing much about boats/motors. I floated and ran so I thought "great"...you see where this is going... We had it out a couple of times ran fine but with a bit of an idle issue so I had it in to the Johnson/Ev. specialists near me to have a general tune-up and go-over. Turns out it's a 140hp power head put on a 90hp lower unit/leg with the starboard lower piston rings broken needing a rebuild. The quote to repair was way more than I can afford but I found a guy locally selling a boat with an early 80's 90hp that runs but has the water jacket bolt stripped but running and decent compression all 4 cyls. Would it be worth getting if the price was low to try and put a decent power head on? The current 140 has already been rebored to 0.030 as well so reboring to .040 would not be worth it to me as the sleeve would be too thin. Anyone have any experience with this sort of thing?
tia.
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: Combining motors?

Many V4 crossflow powerhead components can be interchanged, no problem. Boring a V4 crossflow to .044 is fine, no problem. They can be bored to .064 over.
 

mamm7215

Petty Officer 2nd Class
Joined
Apr 28, 2010
Messages
184
Re: Combining motors?

Thanks, the mechanic said that they don't like to bore to more than .040 because the cylinder sleeve gets too thin...I would assume the 90hp power head would just bolt on the existing leg...
 
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