2000 Sea-Doo XP 951 Rave Valves

[Andy Scarth]

Hi, new poster here. How do you trim the rave valves when installing new bored cylinder and new pistons? Any videos or threads about it would be much appreciated!
Thanks

 

[etemplet]

It is a little tedious when you haven't done it. A course half/round file is my weapon of choice and I like to use the 10" because of the length of the stroke. You need a .015" or "020" shim/feeler gauge, a piston and a really good flashlight. It is a pain at first getting everything into position. Basically you just need clearance so the rave doesn't contact the piston. Pay special attention to the extremities on the rave and rock them back and forth to make sure they won't touch. No need to be excessive in the amount of clearance. The aluminum comes off the valve easily. You'll figure out which point of the valve is the closest to the piston and just kinda match the taper. Make sure you have the valve installed the proper way and MARK the valve so you'll know which engine it is for.

While you have the cylinder on the bench make sure the ports are filed with no sharp edges. Wash the cylinder thoroughly after all the work is done. Hope this helps. Good Luck

 

[Andy Scarth]

It is a little tedious when you haven't done it. A course half/round file is my weapon of choice and I like to use the 10" because of the length of the stroke. You need a .015" or "020" shim/feeler gauge, a piston and a really good flashlight. It is a pain at first getting everything into position. Basically you just need clearance so the rave doesn't contact the piston. Pay special attention to the extremities on the rave and rock them back and forth to make sure they won't touch. No need to be excessive in the amount of clearance. The aluminum comes off the valve easily. You'll figure out which point of the valve is the closest to the piston and just kinda match the taper. Make sure you have the valve installed the proper way and MARK the valve so you'll know which engine it is for.

While you have the cylinder on the bench make sure the ports are filed with no sharp edges. Wash the cylinder thoroughly after all the work is done. Hope this helps. Good Luck

Yes that helps a ton, thank you so much. May need to reach out to you in the future.

 

[etemplet]

The thing to remember is... it just can't touch. I like the idea of a minimum of clearance but I don't want to risk contact with the piston. So if you bore the cylinders .5mil over you're looking at needing to take .010" off to maintain the recommended clearance. That amount comes off quickly but it usually takes me about 5 to 10 minutes per cylinder. If zombies were attacking I could do it a lot quicker.

 

[mikidymac]

I know some people wrap an old piston with sandpaper to get a nice round taper but it is a little difficult to hold the valve at the correct angle.

 

[Andy Scarth]

The thing to remember is... it just can't touch. I like the idea of a minimum of clearance but I don't want to risk contact with the piston. So if you bore the cylinders .5mil over you're looking at needing to take .010" off to maintain the recommended clearance. That amount comes off quickly but it usually takes me about 5 to 10 minutes per cylinder. If zombies were attacking I could do it a lot quicker.

Yea I seen a guy on youtube wrap a piston with 80 grit sandpaper and hold the rave valve flush and take off the material that way.

 

[Andy Scarth]

I know some people wrap an old piston with sandpaper to get a nice round taper but it is a little difficult to hold the valve at the correct angle.

Haha yea I just posted that then seen your comment!

 

[etemplet]

I have wondered if the engine shops have a distance measurement they use for different bore sizes and cut the radius in the milling machine spot on. We'll never know... will we? I'll bet some shops cut the valve for max size and don't care cuz they think it doesn't matter.

 

[mikidymac]

I have Group K do mine and I don't ask for their secrets, LOL.

 

[Poormanracing]

I take a caliper and measure .10 thou grind it close then finish with an old piston of the same size bore.(I never throw away pistons).the only problem with sanding with a piston inside the bore is the races swell faster than the piston and on the race stuff trying to get them close as possible have had them kiss a piston.so a little goes a long way

 

[etemplet]

I take a caliper and measure .10 thou grind it close then finish with an old piston of the same size bore.(I never throw away pistons).the only problem with sanding with a piston inside the bore is the races swell faster than the piston and on the race stuff trying to get them close as possible have had them kiss a piston.so a little goes a long way

That is a good idea not to throw away old pistons. I've had to do some digging on occasion and it is nice to have a pile of parts.