787 Rave Valves

[Lothsahn]

Just went to clean the rave valves on my new (to me) 1996 GTX. Paint on the allen bolts holding on each rave valve looked like they have never been removed, ever.

Think they're a little dirty? I find it amazing this thing ran properly at all.

The front rave valve has fractured at the rod (see the picture). I'm going to replace it. Any recommendations on what part I should buy to replace it? Are they like carb parts where I should only buy OEM, or are aftermarket usually OK?

Is the fracture caused by a bad forging or something else? Should I replace just one or both? Is the other likely to fail?

 

[POPPS]

I find after market rav valves,,,to be inferior,,,get original if you can.
Wow,,,broken...do look thru the rav holes to look for scoring on the Pistons,,,Remove the pto cover,,,remove your plugs,,up ,,,have a really good flashlight of course.,,,and then just move the Pistons up and down as you need.

 

[Lothsahn]

I find after market rav valves,,,to be inferior,,,get original if you can.
Wow,,,broken...do look thru the rav holes to look for scoring on the Pistons,,,Remove the pto cover,,,remove your plugs,,up ,,,have a really good flashlight of course.,,,and then just move the Pistons up and down as you need.

Oh Crud. That... sounds way beyond my capabilities. I'll go check the piston right now, but thankfully the piece that broke off was sitting right on top of the engine and didn't get inside the cylinder. I'm pretty sure the engine is fine as it was running great when I shut down at the end of the day last.

 

[Lothsahn]

Just checked and I can't even see in the cylinder because the exhaust manifold is in the way. Like I said, I'm pretty sure there's no engine damage based on how the seadoo was running.

 

[POPPS]

Apologies,,,meant for you to inspect the rear valve,,,on seadoos that is the piston that has the most failures.,,checking the front is a lot of work,,,

 

[Lothsahn]

Thankfully the rear valve didn't fail, piston there looks good, although I can't really rotate it easily. So I think we're good.

I'm going to order a set of 2 OEM rave vales from OSD. Not cheap, but hopefully they'll last another 24 years.

 

[AKnarrowback]

Read this and order the updated parts.

 

[Lothsahn]

@AKnarrowback I've ordered two replacement Rave valves, gaskets, bellows, and o-rings. It appears I already have the updated housings.

I cleaned the rave valve I didn't have, but since it doesn't have the grooves, I'll just replace both so they match.

Thanks for the help!

 

[POPPS]

Thankfully the rear valve didn't fail, piston there looks good, although I can't really rotate it easily. So I think we're good.

I'm going to order a set of 2 OEM rave vales from OSD. Not cheap, but hopefully they'll last another 24 years.

It concerns me that you can't rotate the crank/piston easily...it should be fairly easy,,,unless you have a top end (piston scored/ring/),,,issue,,,have a bottom end problem,,,or.,,you have problems in the pump area.

 

[Lothsahn]

I meant I don't have the tools or knowledge on how to rotate the crank, not that it's seized.

How would you rotate the crank?

 

[POPPS]

It's easy,,,remove the gray pto cover at the rear of the motor,,,usually it is held on with 2 white plastic wing nuts,,,there may be a washer,,,some times,,,you just loosen the nuts and you slide the cover up and off,,,depends on the model and year,,,.this will give you access to the pto fly wheel,
Now remove your plugs,,,and with the rear rav valve out (the front one is harder),,,you can use your left hand to rotate the piston through the window of the rav valve,,,to look for scoring,,,since this is on the exhaust /hottest side,,a strong narrow flashlight is your best friend here.