Sell the one you have and go out and buy a 90. It's cheaper that way and less of a headache. Not a smarta** answer, I looked into BEFORE I purchased my 90.
They Share the same block, but a lot of the other parts are different. I believe the head and valve train are different, just like the 40/50hp models. Like MajBach said, its better to sell your current and buy a 90. The sum of the parts and labor would cost a substantial amount more than the difference in trade-in and purchase price of a 90.<br /><br />Nav
