Logo

Attempting a rebuild for the first time getting setup to replace a crank is a used crank a bad idea

jon

Regular Contributor
" Hi,

The engine is an


" Hi,

The engine is an 86 merc 115 L6; it was up and running perfectly until the splines on the crank stripped. The compression is 124-130. I have located another engine of the same type, the year is 1985, it has a problem of some sort in one cylinder.

What I would like to do is mix and match parts to build the best engine I can out of the two. I'm planning on pulling the powerhead off bothe, taking the crank out of the 85 and then replacing the crank in the 86 w/ it. My plan is then to put the good powerhead (86) onto the 85.

My main concern at this point is whether or not I'll be able to get the good block apart without snapping bolts, and whether replacing the crank with a used one from a junk engine is a good idea. I'm looking for any advice that will make this go smoother, if there are any shortcuts I should take, or shortcuts I should not take etc. I am also wondering how often a bad crank is the cause of a destroyed cylinder, and what I should be looking for to decide if crank is usable. Thanks for any/all advice,

Jon "
 
" Hi Jon,
As long as the us


" Hi Jon,
As long as the used crankshaft is in good shape (no pitting, excessive wear, etc.) and the bearings are clean and in good shape, then go for it! Should be a relatively easy swap.
- Scott "
 
" Thanks for the input, first

" Thanks for the input, first positive thing that has gone through my head about it.. that's also good news because the part is no longer available new.. not that I would be willing to put up the $$ for it anyway.

It's going to be a few days before I'm even ready to pull this powerhead, so I haven't taken a look at the guts yet, but in the event that my only option is to take the pistons and crank out as an assembly, do you think I should go the extra mile and re-ring/hone with compression like it has now?

Jon "
 
Back
Top