Melted RAVE valves...thread closed???

[scooper77515]

http://www.seadooforum.com/showthread.php?t=6366

Why did this thread get closed and locked down?

I would have liked to see some responses to it and see if anyone else had the same problems.

This engine lasted about 2 more trips before throwing a rod, and it would have been good info if someone chimed in and informed others of the problem when they search for it later.

Anyways, revisited it to see if anyone had responded and found it locked instead.

Any ideas why those were melting?

 

[scooper77515]

Actually, EVERY thread I look at after searching RAVE and melt are closed.

Do we close threads after a certain time, or is there a melting RAVE conspiracy???:rofl:

 

[kustomkarl]

Scott the date of the thread was 7/19/08...if you didn't get any responses by now you probably won't...start a new thread. After several months the thread gets buried and nobody will see it. Seadoosnipe closed it... If we kept every post open after months of inactivity there would be no room for new posts...

Start a new thread.

Karl

 

[scooper77515]

That is why I started this thread, hoping that someone had similar issues and may chime in.

 

[scooper77515]

I read that a couple people had issues with them melting...can some of you guys chime in about how you solved it?

 

[cjb]

Melted rave is a sing of high temperatures due to a lean condition. :hat:

 

[Chester]

What happens is, the valve stem and the housing hole wear out and allow the hot exhaust gasses past. It's not from a lean condition. Replacing both valves and both valve housings will solve the problem.

Chester

 

[scooper77515]

Oh, that was easy. :cheers:

When I was having the problem, I couldn't get any help on why it was doing it, and was swapping out all the plastic and rubber parts.

Got all new stuff on the new motor, so I guess it shouldn't be an issue for a long while...

 

[cjb]

What happens is, the valve stem and the housing hole wear out and allow the hot exhaust gasses past. It's not from a lean condition. Replacing both valves and both valve housings will solve the problem.

Chester

Well that could be too. However, if a lean condition exists the egts can get high and bye bye caps. Of course, engine failure is not too far behind and I believe his engine was failed around the same time. I don’t believe exhaust gases escaping thru a worn rave will cause engine failure. But what do I know. I am just the gorilla in the room. ;-)

 

[scooper77515]

Yes, the engine DID fail while, or soon after I thought I got the RAVEs to stop melting. It was only a couple trips between the last RAVE fix and the engine failure, so the RAVEs may have still been in the process of getting ready to melt.

That is kinda why I was doing research into this issue. I never really figured out why the engine failed.

It is always a good learning experience when I blow something up (blew up a 302 Ford last year, and learned MUCH from that and building up the new 5.0 replacement).

So I was trying to see if the RAVEs caused the failure, were caused by the same thing that caused the failure, or if the melting was a warning of the impending failure. Or if it was just coincidence.

So, Gorilla or not, any feedback helps me put all of this together and see if I can solve the dilemma.

BTW-the 302 cratered because over the years I swapped heads, cam, etc and I erroneously left the valvesprings on when they were too stiff for a flat tappet, and I was pushing right up to the limit of spring movement. Started to eat lifters and cam. Went with a full roller motor next time and matched springs to it all.

 

[seadoosnipe]

Compression?....

What happens is, the valve stem and the housing hole wear out and allow the hot exhaust gasses past. It's not from a lean condition. Replacing both valves and both valve housings will solve the problem.

Chester

I have to agree with Chester. Also, I do believe that this kind of leak, if bad enough, will allow some of your fuel and lubricating of the piston to escape. This may cause seaizure if left un-checked.

I did close this thread due to age. I did not close it in reference to thread replies or username. Before the high traffic season started this year, I went through and closed and organized the forum's topic threads because of members coming in, reading them, then, replying to them.

This became a problem for most threads because a remedy may have already been found from a different thread or it would be confusing because of outdated material being "bumped" back up from a year or so past with responses from members who are not currently posting. Personally, it confused me to come in, try and help and see I made a previous response that I didn't remember. Then, I'd notice the date and recollect it.

Yes, some of them may still be relevant but I'd rather see someone open a new thread after 2 months or so, if it's not a current thread. For instance, the thread Karl created, "the last post wins", is still current because users are still posting to it. So, it was left open. It's over a year old.

Any member can request a mod to open a "closed" thread. We will evaluate that request and determine if it's better to open or make a new thread on an individual basis.

 

[scooper77515]

OK snipe. You have conviced me that it isn't a conspiracy (but I am still wondering....:reddevil

It would sure have been nice to nail down the source of the problem to prevent later failures, and help others catch issues before it happens to them.

I guess we cannot solve ALL problems...

 

[Chester]

Well that could be too. However, if a lean condition exists the egts can get high and bye bye caps. Of course, engine failure is not too far behind and I believe his engine was failed around the same time. I don’t believe exhaust gases escaping thru a worn rave will cause engine failure. But what do I know. I am just the gorilla in the room. ;-)

A lean mixture will seize the engine long before it does any damage to the RAVE caps. I have fixed several melted RAVE caps by replacing the valves and housings, end of problem. I even had one customer that ran his Challenger 1800 for hours with a melted cap. The engine never seized.

Chester

 

[IDoSeaDoo]

I have recently put in a new engine into my 97SPX (with the 787/Carbs) and it keeps melting the MAG plastic rave plunger. The plugs both look like the motor's been running lean, and I have a nasty mid-range bogging that i can't track down. The plugs look pretty white, like I'm running too lean. Is there a way to measure if my rave/housing is out of spec? Does anyone have rave stem diameters I can verify? Should I replace the plunger and turn out my high-speed idle screw and just see what happens? I don't feel like spending $250 on new rave valves/housing...

 

[scooper77515]

IDo, i have a bunch of RAVE stuff for sale. Leftovers from a couple engines I have had. I have one complete set from blade to red-tipped cap. And a bunch of other stuff to go along with it.

I sold all my Seadoos (gone Volvo-Penta) and have parts leftover. here is link to for sale post. Some of the parts have sold already, but described in detail in the thread. Pic of original batch of parts, including the stuff that was already sold.

http://www.seadooforum.com/showthread.php?39348-For-Sale...bag-full-of-787-RAVE-parts.-See-picture