Yep, buddy of mine took his kxf250 out for a spin down a gravel road. Cruisin around 40 mph when all of a sudden. BOOOOM!!! Rod came out the front of the motor. His bro connection yielded $1659 for parts alone. Another $800 or so in labor. So he's given up on the koolaid and is putting a 250 two stroke motor in that chassis. It's an 09 I believe... The best thing is he just had a new top end put in it before this ride.
Someone really screwed that rebuilld up then. Engines can always blow but they do blow for a reason!
Bad part is it's considered a race engine so you don't have to count on any warranty after u put your month's earnings in it.
4 strokes are actually fine and reliable IF u pull the engine apart regulary, but that's damn expensive! So people just keep riding and blow it up -> even more expensive.
I often check(ed) my 2 stroke engines for wear and stuff and by doing so i keep maintenance cost to the minimum. I could make it cheaper and be lucky to have an engine that does not seize, or i could be unlucky and blow my top and bottom end to pieces. Rather spend that little extra to save a big bill, ppl should be doing the same with a 4t but it's to damn expensive for most.
I'm swearing in church now but i loved my 450 KTM to death, it was fun and easy to ride as a beginner and i found the loud roar sexy.
Downpart was that i did not learn a single thing on that 'stick it in gear and cruise around' thumper and that i dumped loads of money into it to keep it running.