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  1. #1

    Join Date
    Aug 2010
    Virginia Beach

    New to GH - 94 - Question about rings.

    Hey guys,

    Wow. What a ton of information on this site. I have been reading for hours. I could use a little guidance.

    I bought a 94 SPI and a 00 GTX about a month ago. My wife and I have been loving them.

    The 94 bogged under WOT a couple of weekends ago. Looks like I lost compression on cylinder one (is that the one closest to the front of the ski?). It would not start at all (sounded like it wanted to but just wouldn't fire). 45/145PSI.

    I'm not skilled in engine verbiage so I apologize if I make a fool of myself. Today I took off the head plate. I then took off the head cover underneath (wow those bolts were on tight). At that point, I could see the two pistons. I bumped the ignition and could see both pistons moving. The cylinder walls do not looked scarred or messed up. The piston ring closest to the front of the ski looks like it has some wear on it (gap). I'm guessing that is cylinder one.

    My instinct is to research changing the rings on that one piston. However, since I've got the top off, should I be looking at doing both?

    Is changing the rings a major job? Today is the first time I've ever seen a piston. I have a couple of friends coming over tomorrow to doublecheck my findings.

    Where's the best place to order a top end rebuild kit or piston rings?

    I have the 85HP engine.

    Thanks for any help in advance. I'm hoping to learn how to do this so I can work on either ski as the need arises.

    Both have gray tempo lines (yuck). I'll replace the lines in the 94 first, after I get compression back (hopefully).


  2. #2
    mibunkerking's Avatar
    Join Date
    Aug 2008
    replace your fuel lines on BOTH ski's ASAP. this will kill your motors faster than anything else. take a picture of the head and of the pistons and post them up here. normally when this happens you end up needing a top end (new pistons, rings, wrist pin bearings, and a bore job).

  3. #3
    flyin' the friendly skies airbornexp's Avatar
    Join Date
    Aug 2007
    Mahomet, Il. USA
    Welcome to GH! there is a TON of info on the older skis here. Make sure to read the stickies at the top of the 2 stroke section as it will help you in your quest. Its good to see that your not afraid to tear into the motor so that will help in putting it back together. Doing a top end for my first time took me no longer than 3 hours...that is once I got the cylinders honed and new piston kits back in the mail. You can order all your parts here at GH. check the OEM parts tab at the top in the banner. use the coupon code GREENHULK to get a discount. Your verbage isnt half bad. we call the front piston the MAG piston for being on the magneto side (charging system) anf the rear piston the PTO (power take off) as in where the drive shaft is.

    when you change your fuel lines make sure to clean out the fuel selector switch too.

  4. #4
    steach's Avatar
    Join Date
    Dec 2005
    Rock Tavern, NY
    you should be able to rotate the PTO by hand now that the head is off. Inspect the holes completely for damage. I've never seen 45# compresion with no damage.(unless your battery was low and you got a bogus reading on the 2nd cyl)

  5. #5

    Join Date
    Aug 2010
    Virginia Beach
    Took a picture of the top of the pistons. What would cause the color difference? Walls seemed pretty smooth. I'm working on getting the top end off. Any tricks? Remove the exhaust/top end at the same time?

    I worked on it until I lost sunlight.

    More tomorrow.

    Virginia Beach
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  6. #6

    Join Date
    Aug 2010
    Virginia Beach
    Couple pics of the block. To my untrained eyes, the cylinder walls look good. I noticed on both pistons, the bottom rings were not "spongy". The top ones sprung out a bit but the bottom ones seemed more stuck. I couldn't get them off the rods. That's a job for tomorrow.

    I'll take more pics then.

    On the pics below, those "streaks" wipe away. I thought they were grooves but they wipe clean. It's very smooth inside.

    Any tricks for removing the wrist pin bearings?

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