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  1. #1

    '98 GP800 - How can I be sure everything is ok?

    Last summer, my '98 GP800 siezed. The front cylinder threw a rod, cracked the case, etc.

    After discussion on here, the case being cracked, my plan to run it completely stock (g/f's ski), etc, I opted to go with a SBT rebuild (yeah yeah yeah, not the point of this thread).

    I put it in 3 months ago or so, went to premix because I thought that could have contributed to the issue originally. Was running a tiny bit sluggish but I thought it was just because of the extra oil due to break-in, and because the carbs weren't tuned yet. Well the front cylinder seized again.

    I took apart the carbs (they were rebuilt just last year), and the front carb was a mess. There was no pop off pressure essentially. Rebuilt the carbs, pop offs all good now. I just got the SBT engine back, and put it in last night with carbs set to factory. Fired it up and it's running smooth again (smoother than it was the last time). I think I'm all good and fixed the troublesome carb, but how can I be absolutely sure all is well?

    Anyway I can test during this break in period if all is well? I can't do a plug chop or tach test since I'm still in the break in period. Help my newbie a** out.


  2. #2
    I keep a close eye on my piston wash!

  3. #3
    Quote Originally Posted by ZMANN View Post
    I keep a close eye on my piston wash!
    Thanks for your response ZMann, since it's an SBT engine, I obviously can't pull the head so I'll have to look at the piston wash through the spark plug holes.

    Sorry for the ignorant question, but since i'm in the break-in phase, and I am running 32:1 oil, should I expect to see regular piston wash? Or should I see a more lean condition (more oil, means less burnable fuel, which means leaner condition)? How long does it take for piston wash to develop? I've only idled the engine so far, and the pistons look "clean" still. Something to be worried about or will it take some running to notice the wash?

  4. #4
    jdog800's Avatar
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    A good way to see if the motor is being broke in correctly is to see what the compression is before its broke in.. then again after about 3 tanks of gas. you should gain a few pounds. If you lose compression then something is wrong.
    You can also monitor plug readings. (do a search to find a plug chart to diagnose different readings) This is not an exact science and it is subject to false readings...but it does give some indictation to whats going on.

  5. #5
    Quote Originally Posted by jdog800 View Post
    A good way to see if the motor is being broke in correctly is to see what the compression is before its broke in.. then again after about 3 tanks of gas. you should gain a few pounds. If you lose compression then something is wrong.
    You can also monitor plug readings. (do a search to find a plug chart to diagnose different readings) This is not an exact science and it is subject to false readings...but it does give some indictation to whats going on.
    Thanks JDog, I guess my fear since I've already siezed 2 engines is that I do damage during the break-in period. We'll see what happens this weekend when I go break it in.

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