98GTX dry cylinder

[slesto]

I've got a 98 GTX and looking for some guidance. I have had no problems until recently. 62 hours on ski. suddenly power just didn't seem the same like it was running on one cylinder. pulled the plug wire while running and confirmed rear cylinder wasn't firing properly... changed the plug just in case no luck so I assumed compression issues. I pulled the rave valve and noticed it was clean, DRY(no oil), and had a chip in it. the piston looks scored and has a piece missing (almost looks like rave valve came in contact???) The other cylinder looks fine. At this point I'm looking at a minimum top end rebuild/replacement. My questions are: What caused one cylinder to operate dry (no oil from pump?). What kind of damage could have been done to the bottom end from a piece of the piston banging around (will I have to replace the whole engine?). If there is no lube to one cylinder does that mean I may not have enough lube to bottom end?

[Speedfreak]

Re: 98GTX dry cylinder

Your problem could be a number of things. Mechanical failure, if a foreign object got in there some how. The carb could have leaned out and caused it. The oil pump could have stopped or a line came off. Without seeing the damage there is no way of narrowing it down.

If that was caused from a lean condtion (the carb) then the bottom end should be fine but will need to be rebuilt to get all the debris out of it. And with that piston skirt in there a new motor is a good piece of mind and then there is that warranty to fall back on.

[slesto]

Re: 98GTX dry cylinder

Thanks for your feedback... I'm going to try and post some photos of the damage after I get home tonight... I just got the head off last night and trying to get the cylinder loose has proven to be difficult. The interesting thing I noticed was that the head for the rear cylinder looks almost new like it had never been firing... either that or the running cylinder was way too rich... hopefully someone with a bit more experience with these engines will be able to provide some info based on the photos...