Does this look infected?

[bmmeadors]

Need some help here guys. I have a 96 SPX that has zero power in the water, but runs fine on the trailer. I have done all the recomended stuff i.e. fuel lines, rebuilt carbs.....etc, with no success. I did a compression check, and got 147 and 148 wit a good compression checker. I thought I would take a look at the intake and exhaust ports in the cylinder. When I pulled the head off it was chewed up pretty bad. Is this something that normally happens on doo's? The gaskets looked good, which would explain the good compression check. Could this be the cause of problem? Do I need new piston heads?

 

[Bills86e]

All those pits are from wrist pin bearing failure. I would advise pulling the jugs, get all the fragments out of lower case, or they will take out the crank seals if not already. Bill

 

[bmmeadors]

Hey Bill. I'm trying to figure out how this happened. So the wrist pin bearing failing is allowing the piston head to come up crooked, which is striking the head, thus causing the pits? Or am I way off? Is there anyway the pitting could be blended out, or do I have to get a new head? Do you think this was a reason for the power loss?

 

[Bills86e]

Failure of the retaining cage or the roller pins allow the piston to go higher in the cylinder, Not good. I suggest a total rebuild before the cases get ruined. The small bits by now have destroyed the rings, cylinder damage, rod damage is present. Bill

 

[bruester420]

I have had many engines look like that. There can be mutiple causes for the pitting on the head and piston.Pray that it is just a wrist pin bearing, Worn connecting rod bearings are the most common cause from my experience. As for re-using the head, I would suggest buying a used head on e-bay. When you get the engine torn down check the clearences on you rod bearings. Make sure everything is well within spec. If it's not then replace it.

 

[bmmeadors]

Thanks for the info guys. Looks like I have a winter project.