why not get a 450? I have a 350sx and on the track sure it feels a little lighter than a 450 but really it's the same bike and the 450 has significantly more power. The light vs heavy feel is 80% due to the type of motor and other moving parts/geometry. 450's and your 350 have a short stroke high reving engine that produces a lot of wheel speed. Ktm and other off road big bores like their 500 are a long stroke lower reving engine that produces tons of torque but they tend to "feel" heavy. Any mass that is moving (rotational mass) makes it feel a lot heavier than it's actual weight. Ktm still makes the 450xcf I think which is a short stroke, same engine as their 450sx, if you want an off road bike for the dirt that rocks. Yet if you buy their 450 exc it will be a heavier feeling longstroke engine (I know, ktm has way too mant models to keep straight). My track kit is on a kx 450 and it rips. I have a ktm 350 and a 2 stroke 300 but I don't plan on putting a track kit on either because even though they would work I wouldn't want any less power than I have now. If I went to a 500 it would be a 2 stroke probably.
