I don't know, pretty much everyone I have talked to and myself included on 2 bikes found the 160 main to be too big.I think if you are only 3/4 of a turn out your pilot may be too big.

Jack I wish I had my dyno print out still, I tuned my bike with the looking at the plugs method and my main setting was dead on right around 13, my pilot needed to be increased and thus my main decreased and now I'm right where I should be. I agree the dyno is the best way but it isn't the only way. I also agree that you can only get so close reading plugs then need a dyno to dial it in perfect or an A/F gauge you can read while riding but I think that would be difficult to get a good idea that way since it isn't as controlled and you need to watch the road.

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