Follow-up on 90 HP Force

[biederboat]

This motor just keeps pulling me in further than I ever hoped it would but there's a slight glimmer of hope here. Bought a boat knowing it had a frozen 1996 90 HP Force (aka "Farce", I know). I was basically relieved that it was frozen when I bought it, thinking there's a good excuse for replacing it with a 4-stroke. Being the tinkerer that I am, I start fiddling with the thing and got it to turn over, one cylinder has no compression due to a failed head gasket, leading to water in the cylinder = rust = frozen head. So, here's where I am now: The piston is pulled out via access by removing the manifolds. The piston looks "okay", needs new rings, and the cyl bore in the bottom stroke has some light rust, but looks like it would clean-up okay with a honing. Now, I don't want to disassemble the entire power head, way too much money or self labor in a Force. So, is it possible to do the honing without disassembling the rest of the powerhead? My main concern is that the honing process might generate debris which would end up in the crankcase and eventually destroy bearings. I've attached a photo so people can see exactly what I've tried to explain.

Anyone have experience in this area? I'm pretty confident (enough to spend money on new gaskets, etc. and spend time) that if I can fix this, the rest of the motor will be fine to use until I replace it with a 4-stroke. On the other hand, selling it as a basket case is what I had planned on when I bought the thing and I only have about 2 hours in disassembly so no big deal.

Thanks,
Biederboat

 

[WillyBWright]

Re: Follow-up on 90 HP Force

Use a green ScotchBrite saturated with oil. Scuff-up the top half of the other cylinders as long as you're in there. When you get it all together and go to start it, use double oil and choke the crap out of it at high idle once it starts, almost to the point of killing it. That should help flush things out.

 

[Frank Acampora]

Re: Follow-up on 90 HP Force

I did it on a Chrysler 140. You need to run the hone slow with the piston at bottom dead center and use a heavy oil in the cylinder while honing. This will keep any grit contained within the cylinder. Then use a lot of clean rags to wipe out the cylinder. Be sure to get into the ports to clean any accumulation there. Clean the top of the block so the head gasket seats properly. If the top of the cylinder liner is rusted too badly, you can go down about .010 with no problem. use emery on a true flat surface like plate glass. Buy a new Head gasket from WISECO They are half the price of the stock part. About $26.

 

[DJ]

Re: Follow-up on 90 HP Force

If you are going to re-ring one cylinder, it cost very little more to re-ring all of them.

Give all three cylinders the same treatment.