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  1. #11
    txgp1300r's Avatar
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    When I had my gp1300r I had to replace at least one piston a year...you can use muriatic acid to remove melted aluminum from the cylinder walls, then use a flat stone hone, new piston and rings...very easy to do. " Myself" in the above post has good advice as well concerning the seals, good luck and have fun.

  2. #12
    So I got pretty bummed out about this whole ordeal, and decided to just spend some money and get something else. I ended up getting a 2018 VX Limited that only had 16 hours on it... included a trailer and all the accessories from Yamaha still in the packages! I deleted the ribbon on it, but other than that it's stock. The thing looks brand new! It's not quite as fast (55 mph on GPS vs 58 MPH on GPS with the GP1200R) but it's fantastic. I LOVE not having to mess with mixing oil and all that nonsense.

    So anyway... if I understand correctly, all I SHOULD have to do, if I want to skip honing the cylinder, is just replace it (and gaskets of course) along with the piston and rings, and it would be up and running again? Would this be a suitable to use for replacements parts: https://www.ebay.com/itm/173982048558 ?? I know that the seals should be checked and so forth, but if I wanted to get it up and running, quick and cheap, this should be all I'd need, correct?

  3. #13
    Adam's Avatar
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    The cause of this problem is twofold, one the powervalves don’t open symmetrically because the plastic joiners flex and fatigue over time . This means the rear cylinder is running at full power try to overcome the drag / lagging of the front two cylinders that are not opening their valves fully therefore sharing the load on the engine . The rear cylinder is severely loaded and can ping under the load and destroy the piston. The fuel pumps can be damaged in the check valves too and cause a lean condition which causes pinging / detonation which destroys pistons . I have made solid metal joiners with lock screws that ensures that all 3 valves open exactly the same amounts together. The plastic joiners are a ticking bomb on this engine format . I have worked very closely on this problem and have cured the problem on a few other skis as well as mine .

  4. #14
    Quote Originally Posted by Adam View Post
    The cause of this problem is twofold, one the powervalves don’t open symmetrically because the plastic joiners flex and fatigue over time . This means the rear cylinder is running at full power try to overcome the drag / lagging of the front two cylinders that are not opening their valves fully therefore sharing the load on the engine . The rear cylinder is severely loaded and can ping under the load and destroy the piston. The fuel pumps can be damaged in the check valves too and cause a lean condition which causes pinging / detonation which destroys pistons . I have made solid metal joiners with lock screws that ensures that all 3 valves open exactly the same amounts together. The plastic joiners are a ticking bomb on this engine format . I have worked very closely on this problem and have cured the problem on a few other skis as well as mine .
    I believe you were correct. When I took the cover off the powervalve area, that stupid little pin had come out, so the power valve obviously wasn't functioning when this happened. I've since ordered the waveater clips, a replacement cylinder and piston. I'm hoping to just pull the cylinder and piston and put the replacement in and call it a day. This thing is too old to put a ton of money in, and I don't feel like doing a complete rebuild on it. It's old news now that I got the VX.

    - Are there any tricks to getting the wrist pin out?
    - How much play is normal at the crank and connecting rod?



  5. #15
    Adam's Avatar
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    A pin that is slightly smaller in diameter to the piston pin and tap it gently while supporting the piston so no side load is transferred to the Conrod .

  6. #16
    butterbean_29512's Avatar
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    The GPR may be old....but when running well it is WAY WAY better than any VX can be! Fun costs money...how much fun do you want to have?

  7. #17
    Adam's Avatar
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    This fixes the power valve opening uniformity.
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