1996 Sea Doo Challenger

[extreme202]

Recently purchased a 96 sea doo challenger, Single 787 Motor. Took it out on the lake and it had no power, it would hit the rev limiter very fast and I wouldn't go any faster than 10mph. So I did some research and ended up finding out the splines on the drive shaft where worn so I bought a new drive shaft, carbon ring, seals and did a whole pump rebuild with a new impellor.

Took it back on the lake and it still felt like there isn't much power, it takes forever to get it up to speed/on plane, Its like its trying to gain speed over a long period of time. But didn't hit the rev limiter as fast. Very frustrating.

As I was winterizing the boat for storage I was curious and I took the rave valves off to check them out they were very gummed up and one of the rave vales was cracked into two pieces.

Could the broken rave valve and them being gummed up cause me to not have the power?

Also should I look into the cylinder head to make sure there isn't any damage done?

Thanks!

 

[jforest]

Correct me if I'm wrong but if they were gummed up, they could have been stuck in the up position, limiting your low end. As far as the one being cracked, does it look like it was hit or is missing any pieces? It might be a good idea to pull the head off regardless and look. It only takes a few minutes.

 

[extreme202]

Correct me if I'm wrong but if they were gummed up, they could have been stuck in the up position, limiting your low end. As far as the one being cracked, does it look like it was hit or is missing any pieces? It might be a good idea to pull the head off regardless and look. It only takes a few minutes.

Yea the rave valve and top defiantly needed to be cleaned. As it being broke it was cracked at the stem (middle) of the rave valve.
I will just order a gasket and take off the head and check it out for damage.

Can the broken rave valve cause me to not have the power?

 

[jforest]

The cracked stem shouldn't affect your power. My question is what caused it to crack. All the rave valve does is ride up and down in that slot, it shouldn't experience any force that would cause it to crack on the stem. I would think the only that could possibly happen is over-torquing where the diaphragm bolts to the stem or the rave valve hitting a piston.

Have you checked the compression of the cylinders? That would be a good place to start.

 

[extreme202]

The cracked stem shouldn't affect your power. My question is what caused it to crack. All the rave valve does is ride up and down in that slot, it shouldn't experience any force that would cause it to crack on the stem. I would think the only that could possibly happen is over-torquing where the diaphragm bolts to the stem or the rave valve hitting a piston.

Have you checked the compression of the cylinders? That would be a good place to start.

No I have not checked the compression yet. I hope its good...

I will also replace and clean the rave valves.

 

[jhjesse]

Gummed up rave valves will cause a power loss. They are designed to open around 5000rpms.
No head gasket just O rings. Be careful taking the head off as it not uncommon for head bolts to be stuck.
I would do a compression test first. Hold the throttle wide open while doing the test. 150psi is perfect anything 120 or less is rebuild time.
Does your rave valves have two grooves in each one? If not, that could explain why one was cracked. Early rave valves had no grooves and causes problems with thermal expansion. Sea Doo changed these to the grooved style.
If compression is good, I would just rebuild the rave valves and call it good. SBT sells valves and rebuild kits. You can also get parts from Minnetonka. He is a member here and sells parts cheap. Super honest guy and great to work with.

 

[extreme202]

I finally got the boat out of storage from the winter. Ended up compression testing it and one of the cylinders are 150 and the other is 140.
I still have to buy a new rave valve i will post pictures later when i take it apart.

 

[extreme202]

So i took apart the rave vales. They are really gummed up. Defiantly need to rebuild and clean them up. I will probably order all the parts from SBT, Rave Vale, Rave Cap, and Rave Rebuild kit.

Here are some pictures of the rave valves. Let me know if you think i should just buy two brand new rave valves or would i be fine just replacing the one but rebuilding everything else on the two.







This is the inside of the cap on the broken rave vale.


This was the good rave valve. Defiantly needs to be cleaned its gummed up.

 

[Dr Honda]

Replace the one... clean everything else. Should be fine.