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  1. #1
    Superman! fivespeedsteed's Avatar
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    useful knowledge about powervalves and wave eaters

    so after catching a ring due to an unknown cause ive been doing research on the powervalve system. after finding that mine looked like this




    i was debating if i had a piston ring rubbing a power valve issue. i guess what i dont understand is that some say that a power valve cant fall down, or be adjusted down in its channel far enough to contact the piston and the ring. yet its a known fact that when a power valve pin comes out, the valve will drop and contact the piston/ring. those two theories contradict one another. if the channel didnt let the valve down far enough, wed all be riding around with power valves bouncing around in the cylinders, causing no problems.

    i started to dig deeper. i called the guy at wave eater, and talked to him. i thought i should post it since i have never read about it before anywhere. he said that when you put the wave eater clip over the power valve, it limits the amount that the valve can travel down since it wraps all the way around. like the clip comes between the jug and the power valve retainer. no one has ever mentioned that as a plus for the clips. sure it holds the pin in, and wont let it out, but what if your cables have been adjusted so the valve can bottom out in the channel in the jug and either the jug channel or pv is worn so it will let it come down further? wave eater clips help that.

    the failure i had was with wave eater clips. and it looks to me like the valve was rubbing the piston ring, but with all these different views on the pv system, who knows.

    philip gpr sells the spacers that hold the valves down a little bit so the exhaust port is more smooth, but if i did those and wave eaters, how does the servo compensate for all that limit on the travel?

    ill confirm the wave eater limiting thing tomorrow, im going to put a straight edge over the pv cover surface and measure to the top of the valve with and without the clip installed.

    ive done a fine job at confusing myself this time.


  2. #2
    If you read my thread, I came into the same issue. One of my pv's was far worse than yours. I am not having any serious issues with the engine, and she runs great around the water other than some cold start stuff. I am reluctant to throw in the new PV's if they are going to be eaten up like these for an unknown to me reason.

    http://www.greenhulk.net/forums/showthread.php?t=176061

    None of my PV pins were missing and none of the PV's had fallen into the cylinder. This damage had to be from something.

  3. #3
    Good stuff this is going to become usefull for me. I am going to be tearing apart an engine and putting in new parts as needed. PV and waveeaters will be on the list.

  4. #4

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    If you look at the top of the valve where the round shaft attaches to the flat valve blade in the above pic, you will see a shiny shoulder. This fits into a machined shoulder in the cylinder valve recess. Look down in there and you will see where the round machined area stops. This is like a travel limit for valve movement. I believe if there is enough "misajustment or wear", this shoulder should stop the valve from dropping far enough to hit the piston. Since both the cyl and valve are made of aluminum, when they consistantly touch, they wear and will let the valve drop further. I have noticed many valves come out with no evidence of contact on this shoulder, but many do, and I think if the "misadjustment or wear" problem is not fixed, then the valve will wear the shoulder down and touch.

  5. #5
    Quote Originally Posted by LT1GMC View Post
    If you look at the top of the valve where the round shaft attaches to the flat valve blade in the above pic, you will see a shiny shoulder. This fits into a machined shoulder in the cylinder valve recess. Look down in there and you will see where the round machined area stops. This is like a travel limit for valve movement. I believe if there is enough "misajustment or wear", this shoulder should stop the valve from dropping far enough to hit the piston. Since both the cyl and valve are made of aluminum, when they consistantly touch, they wear and will let the valve drop further. I have noticed many valves come out with no evidence of contact on this shoulder, but many do, and I think if the "misadjustment or wear" problem is not fixed, then the valve will wear the shoulder down and touch.
    Good thinking. The shoulder on the worn valves were completely worn down. this allowed them to fall down and contact the piston.

    When I am adjusting the PV's, the hole will not line up perfect when the PV's are bottomed out. The directions say to line up the hole, but even at it's bottomed out position, the hole is off center.

  6. #6
    Superman! fivespeedsteed's Avatar
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    If I set the pvs up to be up a little, then put in philip gprs spacers so they don't open as far, how will the servo handle that limited range of motion? Does the servo just stop when the cables reach resistance? Is there any thing out there that keeps them from falling down so far?

  7. #7
    Moderator OsideBill's Avatar
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    Quote Originally Posted by fivespeedsteed View Post
    If I set the pvs up to be up a little, then put in philip gprs spacers so they don't open as far, how will the servo handle that limited range of motion? Does the servo just stop when the cables reach resistance? Is there any thing out there that keeps them from falling down so far?
    Yeah adjusting the cables properly

  8. #8
    lukejaeger1's Avatar
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    That's a great piont LT1GMC. I had a powervalve break and rub against the piston. This was on a reman motor. I don't know if the shoulder was wore down on the cylinder or what. The motor only had 4 hours on it so I don't think the adjustment would have much to do with it. If I get an engine that will stay running I can see where the cable adjustment would play a big factor over time.

  9. #9
    Moderator OsideBill's Avatar
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    There is a pin hole in the #3 pulley and one in the cylinder this is supposed to be adjusted using a 4mm pin so that they line up. Check your service manual for this adjustment.

  10. #10
    Quote Originally Posted by OsideBill View Post
    There is a pin hole in the #3 pulley and one in the cylinder this is supposed to be adjusted using a 4mm pin so that they line up. Check your service manual for this adjustment.
    If you take the cables off of the pulley and actuate it by hand, the hole is almost lined up when the PV's are bottomed out. How am I supposed to line it up if I cannot turn the pulley enough to line it up completely even by hand? The PV's physically hit their bottom out point before the hole can even line up. The pulley only installs one way so what am I doing wrong here? The Ski runs and the valves actuate as normal. I just do not understand the hole in correlation to adjustment. Is the hole the reference to make sure the actuator has a true physical resting point and not a resting point that leaves the valves open in any way?

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