Thread: jetting help
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Old 07-26-2012, 11:45 PM
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Jakobi Jakobi is offline
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Keeping the piston top level with the bottom of the exhaust port (for me it was 1.3mm of gasket) made the 300 feel like a big bad 250. Same engine characteristics of softer bottom, hard hitting and would rev to 10,000rpm.

When I did the 250 I set the piston 0.5mm above the port (from memory), but I was also using a race ported cylinder which sacrificed bottom end for top end, so it all worked out about the same in the grand scheme of things.

I'd be having a look at how the piston sits with the current stack and how the engine delivery is now. If you bump the CR up a bit will you gain some bottom end, not to mention the bike will have more power from top to bottom once you close the squish gap.
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