Rings to 1998 75 Force

I have the Powerhead off my 1998 75 Force and would like your thoughts on whether it is worth fitting a new set of rings whilst motor is off. The compression is 140 even with a weak starter and bent reeds. The motor has done 220 hours. The rest of the motor is in good condition. I don't have much experience with rebuilds. The guy who will hone the cylinders said he would look at the motor with the head removed and work out the condition of the bores. Am I likely to gain much from fitting new rings?

I'm tempted to do it for the experience.

Thanks

TwoFish

Re: Rings to 1998 75 Force

If you can access the rings and not at a ridiculous price, why not change them, especially when you're looking for the experience. Seems like there have been a few threads of recent of folks having issues that were ring-related on this model/year range, so if nothing else, you could consider it preventative.

I'm a fan of the "replace all you can afford" theory if the parts are available and cost doesn't exceed the value of the motor. "New" is always going to be better than "not new".

Re: Rings to 1998 75 Force

Not if the problem is something else.
To re-ring is a lot of work.
If the cylinders are in good shape,no scrapes or grooves,leave them alone.

The bad reeds shouldn't have anything to do with compression

Re: Rings to 1998 75 Force

Ever hear the saying...."If it's not broken, don't fix it" LOL! There's a reason for that saying. All joking aside, it's really up to you whether or not you want to replace the rings. I would tend to agree with Jerry. There is no benefit other than the experience, and there are a lot of possible negative consequences.

Re: Rings to 1998 75 Force

Thanks for the replies.

I know it is sound advice to leave the rings as they are but I’m having a “Wet Paint. DON’T TOUCH” moment. Hopefully sanity will prevail.

Just took the head off to get a good look at the bores. They look fine to me. The head gasket looked to be sealing ok. The parts of the gasket that weren’t compressed look a bit worse for wear. I take it that the pistons have some sideways play in the bore when they are cold. All pistons had the same play.

Is 140 psi a reasonable compression figure? The engine builder thought it should be closer to 180 psi.

I have left the head and gasket as they were so I can show the engine builder next week. He seems a really decent guy. I was referred to him by someone that I trust. Plus he has said exactly what you guys have said “You can put it back together and run it as it is. Or you could put new rings in. It is really up to me.”

I’ll let you know how I get on.

Thanks

TwoFish

Re: Rings to 1998 75 Force

Factory specs for your motor are for cylinders 1 and 4.... 135-145 PSI (931-1034 kPa). For cylinders 2 and 3... 145-160 PSI (1000-1103 kPa). I would say you are within normal factory tolerances. From what I've seen and I'm no expert in this area, but 140 PSI is a good reading. At least not bad enough to cause concern. When you see readings that are 100 PSI and lower, then that is a reason for some concern.