sosomechanic
Member
- Jan 8, 2001
- 24
- 0
I'm tinkering with some cylinders on later 250 MX bikes with the aim being a torquier low end and far more linear power delivery. I know that for an engine somewhere near 200 cc's the two KDX engines (200 and 220) are said to be not too far on either side of that description. I've recently turned down the cylinder base 1.5mm on my '03 RM 250 and made a 19 ounce flywheel weight ( that's not a typo, the 10 ounce I made first wasn't enough) to tame it for eastern woods use. Results were very favorable but still not as controllable or torquey as I'd like and it still has overrev to spare. I'm really interested in comparing my current port timing to some of the enduro bikes to see how they differ before cutting chips on a couple of my friends bikes. Losing significant peak horsepower and overrev is rarely noticeable in our riding conditions and isn't much of a concern. If anyone has mapped or run across the port timing specs for these or perhaps some similar enduro machine between 200 and 300 cc's ( like the KTM EXC's or GasGas enduro bikes) I'd appreciate the 411. Thanks, Michael.
