hi, i recently bought a boat that came with a 90hp inline 6 that the lower unit locked up and stripped the driveshaft and crankshaft splines. is there any way to fix the crankshaft spline other than pulling the powerhead apart and replacing crankshaft? thanks
If it's a 99-c.i. engine, any 99-cube (non-racing) crankshaft will work. Just change the reed stops or swap reed blocks to the donor crank.
If it's a 90 c.i. there are a few different styles, '64-older and '65-'70. The big distinction there is whether the upper and lower crankshaft ball bearings are pressed into the bearing caps and a slip-fit on the crank (older), or pressed onto the crank and a slip-fit into the bearing blocks (later-models).