Rod Bearing Damage - '89 Johnson GT 150

[WavyD]

Rod bearings (Retainer Set) on this motor failed...(only one)
Damage:1 scored cylinder, 1 damaged piston, 1 rod, dings in cylinder head,,and slight ding in cylinder crank case(do not believe an issue)

My questions
1) the section on the crankshaft where the bearing failed....can it be turned/machined or is the crankshaft damaged and not repairable ?

2) The cylinder head has a few slight dings,but as I see it, I do not think this will effect the integrity or performance of the head ...correct ?

3) being that the crank case cylinders would need to be bored, is it worth it ?


Thanks and I'll try to post some pics soon.

*edit: i mention "rod" being damaged above...the rod is not damaged,only the bearings,but i feel the rod may have suffered high or extreme heat....so thoughts on heat damage to rod would be appreciated.

 

[wilde1j]

Re: Rod Bearing Damage - '89 Johnson GT 150

While technically possible, it's not economically feasible to rework a damaged crankshaft. You could probably find a good used crank (and a cylinder head) for a small fraction of new ones from a salvage yard. You should be able to tell if the rod was heat damaged from inspection. If you can't, find someone with the knowledge who can.

 

[dazk14]

Re: Rod Bearing Damage - '89 Johnson GT 150

post some pictures. Boring a cylinder is ~$50. Cranks can sometimes be polished back into service. Small pits are usually fine. Rods can also be polished and made useable, how blue is it?
A few slight dings in head may be OK after a bit of hand finishing.

As I said, post pics.

 

[emdsapmgr]

Re: Rod Bearing Damage - '89 Johnson GT 150

I'm with wilde on the crank. You can find great deals on salvages cranks for crossflow V6 engines. I ran one for years. You can get a salvaged rod from the same outfit. It is acceptable to overbore just one cyl, leaving the others at standard size. Pits in the head can cause hot spots and preignition. The factory does not recommend reusing pitted heads-it's your call on what risk you are willing to take on a rebuilt powerhead. That GT model does have higher compression heads than a standard 150-puts out close to 165 hp.