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  1. #1

    What should I do with this 1200r motor?

    Iím not sure how many hours she has on her but Iím guessing around 70 or so? Everything inside the hull is in excellent cosmetic condition. The catís blown out and the oil line on #3 was just about to come off. It was still injecting into the carb but itís also been leaking. The compression is 110 across all three so I didnít think it was too far gone to cause damage. I didnít do a pressure testÖ didnít read that thread until it after I had taken the top off.

    Domes all look the same. The piston wash looks like she was running a little lean. Probably from the cat being blown out? (#3 is on the left)

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    The #3 piston is scraped up but the cylinder was just barely affected. Thereís a ľĒ long, very shallow nick that you have to try real hard to find with your fingernail. Thatís the only flaw that can be felt in all those scrapes shown in the cylinder photos. And itís no bigger or worse than the nick in #2 caused by a burr someone missed. I don't have a set of miks accurate enough so should I take the jugs & pistons in to have measured and possibly honed? Cyl. #1 is in ex. condition and the compression is even on all three.

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    This is the nick & what remains of the burr in #2...

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    I have about all the new gaskets and seals needed for the top. Can I get by with just replacing the #3 piston and three sets of rings? Can I replace it with a low hour oem or go with a new pro-x? Or, given the hours, age, and lost compression, should I go with three new pro-x kits? If they still have plenty of life in them and if it's not going to improve compression/Hp, I'd rather re-use my two good pistons.

    Also, should I split the cases and replace the crank seals? Can they account for the lost 10 psi? Or, should I put the top back on and do a pressure test before tearing it down anymore? I have the crank seals already so maybe I should just work on the bottom also while its out?

  2. #2

    post a WTB thread in the classifieds to see if anyone can help you out with parts...

  3. #3
    I need new jugs and pistons + rings + bearings? Or, do I need a lightly used set of pistons and some new rings?

  4. #4
    Quote Originally Posted by Gannz View Post
    I need new jugs and pistons + rings + bearings? Or, do I need a lightly used set of pistons and some new rings?

    This can be a bit difficult diagnosing off the internet.
    First thing that needs to be done is what caused the failure or condition and correct that.
    To re-use anything of what you have needs to be checked. Condition, age/hours will help determine.

    You need to evaluate what you want to do and proceed from there. It`s hit or miss with used parts if you want a successful reliable ski. Determine if you want to keep it for a few seasons, or your putting a bandaid on it to sell.

    IMHO since you have the engine relatively apart and if your are mechanically inclined, you should pull it down and install new seals, check out the crank and start off with a good reciprocating assembly.
    Having Cylinders renik`d can be $$$.
    depending on your goal, you could find a good used cylinder(s) and matching piston(s).
    I don`t think I would install all new pistons in your used cylinders unless they were in perfect condition if you needed them.

    maybe start a build thread in the projects forum, if you do decide to go thru with this project and take a ton of pics and give a good description and detail to get the best accurate help. Suggesting you just change out a few parts would be futile. Starting off with a good base and doing what you can first, will produce better results.

    what`s the story on cylinder #2? that could be a spot in the Nikasil since new unless something happened that you are aware of?

  5. #5
    so what`s the skinny with this ski???

  6. #6
    Thanks for checking! Sadly it's on hold... wife's transmission died so all my 'spare' time is being spent under her chassis.

    I'm also waiting on a set of micrometers to arrive... always looking for an excuse to buy new tools.

  7. #7
    Jugs are all in great shape. Miked out at 3.15005 (estimated halfway between the 0 and 1) and 3.1501. Out of round and taper limit is no greater than .00005.

    Going to go ahead with one replacement piston for #3 and new rings all around. Should I go with a low hour, used OEM piston or a new Pro-X? OEM rings or Pro-X? My jugs are stamped 30809... which pistons do I have/need? Red, orange, green, or purple?

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