I'm sure this has been discussed before, but is there any special maintenance I need to be doing when dual sporting a power valved two stroke? Going to be rebuilding the top end of my WR250Z this year, and I've only ever dual sported another two stroke once. My buddy on his KTM 300 gets about 200 hours on his top end or so, but doesn't really flog it and that sounds like he's really stretching it. I don't particularly flog mine, and I'm at 14/48 gearing, where the PV just starts to open cruising at 50. 90% of my riding is moderate paced two track, with some occasional single, etc. Given a 250 revs faster than a 300, I'd imagine things wear out a bit quicker. Once I get this jug off (I stripped one of the nuts, and can't get anything but a wrench on it -- I stripped it with a 12 point, and just got a 6 point) I was going to do a preventative top end as well as check tolerance, replace crank seals, and put an hour meter on her. I don't know how much extra wear and tear on top ends dual sporting does, if any, than say strictly dirt riding, etc; and I'm wondering how many hours I can get on average before I decide to go back inside.
A 250cc doesn't significantly rev much different than a 300cc. Porting and pipe will have much more effect than 50cc. No difference with the top end with dual sport, more shock load on drive train from high traction on pavement. Don't try to compare Yamaha to KTM wear, worry only about how your particular bike is doing.
