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Thread: Lean on #2

  1. #1
    JKR1300's Avatar
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    Lean on #2

    In the last month or so ever since it's been really hot, my #2 piston is running lean. I turned the fuel controller progressively richer both yellow & red dials over the last couple of weeks, and I can tell 1 & 3 are running richer, but 2 is still running lean when I read the plugs. My compression is good, 150 / 150 / 145. Never had this problem before. All 3 plugs have always looked the same. The engine seems to run really hot in this 95+ degree weather with 90 degree water temps. You can barely touch the head. This is not the case when it's 75 out. It still runs good with no readily noticable drop in performance or top speed. The other day with temp's over 100 I ran 76.7 @7200. Any chance the injector is partially glogged? I'm not sure what else could cause this. I'm running pre-mix


  2. #2
    Chine Walker
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    JKR:
    Have you considered running Yamaha's Ring Free fuel additive to see if the possible clogged injector will clear itself out?
    Just a thought...

    jp

  3. #3
    JKR1300's Avatar
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    I always use ring free - 1 oz / 10 gallons for continuous treatment. I've also tried the shock treatment.

  4. #4
    JKR1300's Avatar
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    Anybody else with helpful ideas??

  5. #5
    You can physically remove all 3 injectors and look at the fine screen on the inlet side. Helps to use a magnifying glass. I have seen buildup on them before.. That is where i would start, if all looks good, spend the money to have the injectors flow tested, and ohm tested.. Ross

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