89 85 hp lost middle cylinder

[Tim Wagner]

Not sure what to do here.<br />Motor started acting abnormal and I managed to get it back to the launch a pull it out of the water. (I screwed around with it for a while and finally got it started.)<br />Checked compression and bad news! <br />Top cylinder is about 108 psi middle is 0, nada, none and the bottom is 65 psi.<br />I yanked the head to see what I can see but not sure what Im looking at.<br />The top piston is totally carbon corroded and pitted all over. the cylinder walls look like the middle cylinder which has no compression. (there are score marks about 5/8 inch wide here at the bottom)<br />They are not deep.<br />The middle one has these score marks on the cylinder walls and the top of the piston is like the top piston but not nearly as bad.<br />The bottom piston looks even better than the middle one and the cylinder walls look good. Nice cross hatch hone marks. Nothing scored.<br />Is there a way I can get the pistons out of there without taking the whole motor apart????<br />What would be the best case scenario for this repair?? I know the worst case.<br />Anything special to look for.<br />Im hoping for 3 new pistons, get the cylinders re-honed real nice. Replace all the gaskets I disturbed ripping it apart. Slap it back together and be off and running.<br />-Or is this just wishfull thinking?

 

[dave in toledo]

Re: 89 85 hp lost middle cylinder

have to remove powerhed from boat, hve parts machined and rebuilt

 

[seldont]

Re: 89 85 hp lost middle cylinder

Actually I think you can remove the carbs and the intake from the front and the cylinder head at the rear, unbolt the rod caps and push the piston and rod assembly out. At least you can on a 120. But if you have much scoring at all you may need to have they cylinder bored which would mean removing the powerhead.

 

[dave in toledo]

Re: 89 85 hp lost middle cylinder

I was realy surprised when i did mine, that the little scratches in my cylinders were deeper then i would have thought