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  1. #1
    SMLaker's Avatar
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    Sep 2008

    GP1200R Lean Cylinder - What to do next?

    My current setup: Y2K GP1200R, brand new SBT PV engine (no I didn't do a leakdown), New Reeds & Plugs, carbs rebuilt 3 years ago. Riva-D & Chip. My previous engine burnt the rear cylinder. Thought it may have been related to fuel delivery so I modd'd the fuel delivery to a dual parallel feed. Capped of the regular fuel intake and now feed fuel into the two hoses between carbs 1&2, 2&3. The ski starts and idles fine around 1200rpm. Accelerates kind of choppy off of idle, starts off slow (no bogg) then jumps in power. Power curve is ok after that and top speed is ok ~55 (on the speedo) for a stock GP w/D-plate. Now, front cylinder is running lean, other two look ok. I'm thinking I can back out the low speed jet 1/8 turn to allow more fuel and check condition again. Or, back out high speed jet 1/8 turn.

    I think everyone is going to respond with "do a leakdown test" but I prefer to trust that SBT didn't give me a POS that leaks. Their QC
    is pretty good IMHO. So, the question is.....will backing off the needles be a good first step? I may also go back to the stock fuel
    delivery setup (first) to see if that makes a difference. My previous engine had a rich front cylinder, perfect middle and lean rear.
    Now I've got a lean front and perfect middle and rear.


  2. #2
    Always start rich, go rich and sloooowly work down, start 1/2 turn over recommended factory setting, forgot, your in the Kawasaki section yamalog is over younder !

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