been there with a Honda already . Been in this game 40 yrs now the. KTM 450 is far ahead of the game, it is cheaper to maintain than the 2 stroke. Dosent matter if you agree or not, just the way it is.
Been on KTM's for 17 years now. I will say they make a pretty bullet proof 4 stroke but not like they used to. I have an 01 520 that has had the valves adjusted maybe 4 times, other than that, a water pump seal (what a b*tch that was). All my buddies with newer 250sxf's and 450sxf's have had to rebuild.
I run smokers on the track, and any way you slice it, a rebuild on my 250sx is cheaper....hands down. Especially when you can source the pistons straight from KTM's manufacturer.
I will give you this tho, if you aren't riding the 4 stroke hard...it's pretty bullet proof. It's when you are racing and wringing the snot out of them, it can get expensive!