Lower units compatible?

Well my 135hp evinrude Model # 135383M is still at the shop for an eval. It froze up on me and I didn't know what else to do. I went to check on it (to no avail) however while up there I bought another boat motor and trailer for $100 (I figure I can't loose, worst case scenario I have an engine I can tear apart to learn from) The motor I got is a 115 Johnson Model # 115ESL73M. I pulled the drain plug on the lower unit and it looks like they may have had regular motor oil in it!! There was also shavings in there, so I figure it is prob shot. This LU looks to be the exact same as my 135Rude. If the cost of repairs are more than I am willing to pay I was wondering if I could put my old LU on this motor to get me through the season (then I will learn more this winter!! Both engines look almost identical with the exeption of the "Bubble" (cooling system) on the back of my 135. So my question is...are these Lower units interchangagle? Thanks in advance!!

Re: Lower units compatible?

The LU's are 100% compatible, as are 99% of the other parts (1973-77 V4s all same, except 1977 140hp). The driveshaft on the 135 may be full-thickness, instead of necked down in the midsection - don't worry, won't affect function at all.<br /><br />That bubble is a tuned exhaust. Not worth swapping over - won't make enough difference.

Re: Lower units compatible?

What is the difference in the 77 140hp?<br />Thanks

Re: Lower units compatible?

Evinrude V4 motors made before '77 used a shift assist with a pump in the lower end. This was changed to a more simple bell crank device along with a more streamlined leading edge on the lower unit for 78 and later. The water pumps also went from 2 tubes to 1 tube.