Question about 2003 Suzuki RM 125

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Detonation damage to cylinder head

2008 RM85, I'm experiencing detonation damage to the head, I've check ed the ignition system: All tests were in spec and all though I don't have a peak voltage adapter I am getting a spark, The only issue is with the CDI unit. Refering to the manual page 13-4 has a table of the readings that should be found from wire to wire. All are in spec except cable four which is the Blk/rd wire of the three pronged plug. I read O.L. with the neg #4 to on any other wires from the CDI unit. Can this Cause detonation?

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Detonation is normally caused by compression being too high for the particular fuel you are using.
Try using a higher octane fuel, and see if it still detonates. I am not sure what octane fuel you are running, but use the highest available, or else try a mix of racing fuel and highest octane pump gas available. I seriously doubt your problem is electrical.

Posted on Mar 01, 2011


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