Since there doesn’t seem to be any knowledge regarding rebuilds on Power Valve skis I figured I’d dump what I have found to work on rebuilding them.
To get started I would recommend the following tools:
Needle nose pliers - this is to remove the old rubber circular gaskets stuffed into each side of the PV cylinder.
Alan keys - there are a total of 2 different size Alan key screws that hold the lever links and the Power Valve in place.
Rubber Mallet - helpful to get stuck PV rods out.
Dremel (likely not needed) - used to resize PV slot in cylinder if your PV doesn’t clear.
Loctite red (optional it’s how Yamaha put them together) - used on alan key screw holding PV against cylinder. (This is not the Alan key screw going through the PV rod)
2 stroke engine oil - use this to lubricate the PVs and PV slot before completing the rebuild.
Snap ring pliers - used to remove the 2 cir clips on each PV rod (there’s only 1 cir clip on the main cylinder where the PV cables connect)
Wave eater clips - if you aren’t using aftermarket lever links (if you’re not sure what this means refer to the picture below… the black clip on OEM is the wave eater clip)
So let’s get started
The easiest way I have found to preform the install and cleaning of the Power Valve is to remove the cylinders themselves.
The power valves are located here:
Can you do it without removing the cylinders?
Yes but, if you have a busted Power Valve you will have to take off the cylinder to get it out.
Once you get down to the cylinder you need to remove the PV cover (It should be a total of 4 bolts per cylinder)
You should have something like this after removing the covers.
The easiest way to proceed from here is to remove the rear cylinder about 1/2 way and spin it to the left so that the tension on the spring is loosened. This way you can separate the middle piece holding the 2 PV rods together.
After you remove the center piece you need to take your cir clip pliers and remove the cir clips on either side of the rod.
The PV is assembled as follows.
(Starting with rear cylinder)
Cir clip >> washer >> lever link << washer << cir clip << connecting bit >> cir clip >> washer << lever link << main PV disk thing
After you remove the cir clips and washers your next step is to remove the PV rods. (You must remove the Alan key screw attached to the lever link prior to removing the rods)
Note: if your rods aren’t coming out easy use a rubber mallet to hit it out, if it gets stuck in between your lever link, use a longer bit (Phillips, flat head, etc) and use the flat part of your bit to hit the rod through.
After you remove the rod your lever link should just pull out and you should now have a power valve held in place by a single Alan key screw.
NOTE: EXTREMELY IMPORTANT!!!!!
If you have the original OEM lever links it is strongly recommended to install wave eater clips.
This will prevent the pin on your power valve from dropping into your cylinder if it breaks.
Refer to the picture below if unsure.
(OEM lever link has a wave eater clip pictured)
Remove said Alan key screw and remove the Power valve.
Note: if your power valve is broken you will likely have to remove the cylinder and be extremely careful to hit out the broken power valve using a flat head and rubber mallet to hit it out. (flip the cylinder upside down and hit the bottom of the PV until it comes out)
You should now have something that looks like this:
After removing the Power Valve, remove the rubber circular gaskets using needle nose pliers. (There are 2 of them per cylinder) It may take a bit of fighting to finally get them out…
After removing the old rubber inserts.
You can start cleaning up the slots until there’s no more gunk. (Use wd40 or go wash the cylinder, Power valve, lever link and PV rod with hot water, soap and a toothbrush)
After you get your cylinder cleaned up install your new rubber inserts. (Take a rubber mallet and make sure they are fully in by hitting them till they are flat)
Use 2 stroke oil and oil up the entire PV slot also make sure to oil up the Power Valve prior to installing.
Install your Power Valve into place.
Note: if your power valve doesn’t clear the slot you may need to dremel the slot the PV slides into to open it up a bit. (This is the circular bit the larger bit of the PV slots into NOT the larger hotdog shape)
However, before you do this make sure your power valve fits in the other cylinder.
(This scenario typically happens when there’s one broken PV and the other side is working… overtime the cylinder will overheat and morph the PV slot)
Picture below showing this issue:
After you install the Power Valve and screw the alan key back in make sure the power valve freely moves up and down if it does you can add loctite red on the threads of the Alan screw holding it in place. (You don’t have to do this but, this is how Yamaha did it from factory)
If it doesn’t freely move up and down clean any residual residue that may be in the PV slot and add more 2 stroke oil. You should be able to move it freely up and down with your hand.
If it’s too tight and it’s repeatedly binding keep working the PV up and down for 2-3 mins, adding 2 stroke oil, this should free it up. (If it fails remove the PV and bench grind it to remove any buildup and try again.
After you install the PV and the Alan screw holding it into place insert your lever links on top of the PV and start sliding the rod into place.
Use 2 stroke oil on the rod to help ease it through.
Note: If you are using OEM lever links the wave eater clip, you should be installing, sits on top of the lever link.
If you’re rod isn’t going through easily use a rubber mallet to tap it in, use a longer bit if needed, to help push it through.
Before adding the washer and cir clip on the end of the PV rod. Align and add the Alan screw through the lever link. (You can use a flat head to help turn the rod if needed)
Again the assembly of the PV is as follows:
(Starting with rear cylinder)
Cir clip >> washer >> lever link << washer << cir clip << connecting bit >> cir clip >> washer << lever link << main PV disk thing
After you hook everything up make sure your power valves move when you turn the disk on the front cylinder (do this by hand).
If they aren’t make sure your center attachments joining each PV rod are properly connected.
After that put the PV covers back on and reattach everything.
Congrats that’s everything!
How to tell if you have Dropped/broken power valves:
wave eater clips don’t stop your power valves from breaking rather they hold the pin going through the power valve in place; this prevents the pin from dropping and destroying your cylinder(s).
Symptoms: ski idles and accelerates fine on the trailer but, limits rpm in the water.
Ex: of noticeable difference upon removing PV covers.
To get started I would recommend the following tools:
Needle nose pliers - this is to remove the old rubber circular gaskets stuffed into each side of the PV cylinder.
Alan keys - there are a total of 2 different size Alan key screws that hold the lever links and the Power Valve in place.
Rubber Mallet - helpful to get stuck PV rods out.
Dremel (likely not needed) - used to resize PV slot in cylinder if your PV doesn’t clear.
Loctite red (optional it’s how Yamaha put them together) - used on alan key screw holding PV against cylinder. (This is not the Alan key screw going through the PV rod)
2 stroke engine oil - use this to lubricate the PVs and PV slot before completing the rebuild.
Snap ring pliers - used to remove the 2 cir clips on each PV rod (there’s only 1 cir clip on the main cylinder where the PV cables connect)
Wave eater clips - if you aren’t using aftermarket lever links (if you’re not sure what this means refer to the picture below… the black clip on OEM is the wave eater clip)
So let’s get started
The easiest way I have found to preform the install and cleaning of the Power Valve is to remove the cylinders themselves.
The power valves are located here:
Can you do it without removing the cylinders?
Yes but, if you have a busted Power Valve you will have to take off the cylinder to get it out.
Once you get down to the cylinder you need to remove the PV cover (It should be a total of 4 bolts per cylinder)
You should have something like this after removing the covers.
The easiest way to proceed from here is to remove the rear cylinder about 1/2 way and spin it to the left so that the tension on the spring is loosened. This way you can separate the middle piece holding the 2 PV rods together.
After you remove the center piece you need to take your cir clip pliers and remove the cir clips on either side of the rod.
The PV is assembled as follows.
(Starting with rear cylinder)
Cir clip >> washer >> lever link << washer << cir clip << connecting bit >> cir clip >> washer << lever link << main PV disk thing
After you remove the cir clips and washers your next step is to remove the PV rods. (You must remove the Alan key screw attached to the lever link prior to removing the rods)
Note: if your rods aren’t coming out easy use a rubber mallet to hit it out, if it gets stuck in between your lever link, use a longer bit (Phillips, flat head, etc) and use the flat part of your bit to hit the rod through.
After you remove the rod your lever link should just pull out and you should now have a power valve held in place by a single Alan key screw.
NOTE: EXTREMELY IMPORTANT!!!!!
If you have the original OEM lever links it is strongly recommended to install wave eater clips.
This will prevent the pin on your power valve from dropping into your cylinder if it breaks.
Refer to the picture below if unsure.
(OEM lever link has a wave eater clip pictured)
Remove said Alan key screw and remove the Power valve.
Note: if your power valve is broken you will likely have to remove the cylinder and be extremely careful to hit out the broken power valve using a flat head and rubber mallet to hit it out. (flip the cylinder upside down and hit the bottom of the PV until it comes out)
You should now have something that looks like this:
After removing the Power Valve, remove the rubber circular gaskets using needle nose pliers. (There are 2 of them per cylinder) It may take a bit of fighting to finally get them out…
After removing the old rubber inserts.
You can start cleaning up the slots until there’s no more gunk. (Use wd40 or go wash the cylinder, Power valve, lever link and PV rod with hot water, soap and a toothbrush)
After you get your cylinder cleaned up install your new rubber inserts. (Take a rubber mallet and make sure they are fully in by hitting them till they are flat)
Use 2 stroke oil and oil up the entire PV slot also make sure to oil up the Power Valve prior to installing.
Install your Power Valve into place.
Note: if your power valve doesn’t clear the slot you may need to dremel the slot the PV slides into to open it up a bit. (This is the circular bit the larger bit of the PV slots into NOT the larger hotdog shape)
However, before you do this make sure your power valve fits in the other cylinder.
(This scenario typically happens when there’s one broken PV and the other side is working… overtime the cylinder will overheat and morph the PV slot)
Picture below showing this issue:
After you install the Power Valve and screw the alan key back in make sure the power valve freely moves up and down if it does you can add loctite red on the threads of the Alan screw holding it in place. (You don’t have to do this but, this is how Yamaha did it from factory)
If it doesn’t freely move up and down clean any residual residue that may be in the PV slot and add more 2 stroke oil. You should be able to move it freely up and down with your hand.
If it’s too tight and it’s repeatedly binding keep working the PV up and down for 2-3 mins, adding 2 stroke oil, this should free it up. (If it fails remove the PV and bench grind it to remove any buildup and try again.
After you install the PV and the Alan screw holding it into place insert your lever links on top of the PV and start sliding the rod into place.
Use 2 stroke oil on the rod to help ease it through.
Note: If you are using OEM lever links the wave eater clip, you should be installing, sits on top of the lever link.
If you’re rod isn’t going through easily use a rubber mallet to tap it in, use a longer bit if needed, to help push it through.
Before adding the washer and cir clip on the end of the PV rod. Align and add the Alan screw through the lever link. (You can use a flat head to help turn the rod if needed)
Again the assembly of the PV is as follows:
(Starting with rear cylinder)
Cir clip >> washer >> lever link << washer << cir clip << connecting bit >> cir clip >> washer << lever link << main PV disk thing
After you hook everything up make sure your power valves move when you turn the disk on the front cylinder (do this by hand).
If they aren’t make sure your center attachments joining each PV rod are properly connected.
After that put the PV covers back on and reattach everything.
Congrats that’s everything!
How to tell if you have Dropped/broken power valves:
wave eater clips don’t stop your power valves from breaking rather they hold the pin going through the power valve in place; this prevents the pin from dropping and destroying your cylinder(s).
Symptoms: ski idles and accelerates fine on the trailer but, limits rpm in the water.
Ex: of noticeable difference upon removing PV covers.