1997 challenger 1800

[R001norris]

Had my boat at the lake last Sat., and when I got home I looked at engines, and one of the rave valves melted.Bad impeller? This was the first time I’ve had it out since I bought it last year.So I’m new to these motors.

 

[IDoSeaDoo]

Oh boy. That dreaded issue. Idk how many of those rave pistons I melted. A dozen at least between my challenger and SPX. I think my main issue was clogged cooling passages. My challenger had a tiny shell in the muffler fitting where the drain off the back of the cylinders attached. My SPX had that drain line completely clogged with sand. The engine will run with it clogged, but it won't circulate properly and run hot. If you're not running a water strainer, you SHOULD. Once you make sure your lines and fittings are clear and that wasn't the issue, you may have worn out rave valves and housings. This allows excess exhaust gasses to enter the bellows and melt stuff. The reason I mentioned cooling lines first is I replaced those housings and raves and they still melted stuff that same season. I only used OEM parts too. These 787s were so troublesome to me, that I only have one, and for it, I bought aluminum rave pistons on ebay. I also run a strainer on all my boats and pwcs

 

[R001norris]

Good to know! I’ll check the cooling passages. The boat has not been ran in over a year, because the rave valves were shot. I put it in a shop and they replaced the 4 on the engines. But only 1 melted, so that should narrow it down a little. I’m gonna check into the alum rave valves though!

 

[mikidymac]

They melt because the o-rings get hard and don’t seal the exhaust gasses out. Next would be worn out housings but it’s typically the o-rings.