250-500cc WR300 Engine Trouble

I was wondering if anyone out there has had or herd of any trouble with the WR300 Engine. When i first got my bike it ended up seizing at 80km due to a faulty bore, no worries bout that then, but i had a look at the bore today with a camera through the spark plug hole and there were lines and scrapes down the side of the barrel. Is this normal or should i know any news about this.

Cheers guys,
Nick

If the marks are vertical then it's from the piston seizure. If the lines are small angled marking that create an 'X' pattern then that's the crosshatch marks from cylinder prep and that's completely normal.

When the incident happened did the cylinder get replaced!?!?

Pull off the head and get some pics if you can.

You might need a closer look at the cylinder(check the piston as well).You may need to check other things as well...like if you have a leaking crank seal(flywheel side,which if it is,could lean engine and cause top end problems/clutch side leaky seal would consume trans oil and smoke badly).It is very rare for a new bike to have this but we are humans and human error does happen.Anyway,whoever did the repair previously should have done a leak down test after repairs.
Other things to help diagnose vertical lines in cylinder are:have you had the occasion to run in extremely dusted or wet conditions?...if so you could be sucking dirt into cylinder.Also check that the filter is seating properly.Have you allowed the motor time to warm up properly before going WFO?.....sometimes referred to as "cold seizing".2 stroke oil type and mixture ratio or low octane/old fuel can also figure into this .
Since I haven't seen the actual problem and don't know you or your procedures,these ideas are just that,ideas that could have led to your condition.It is best to check with a qualified tech to locate your source of the problem.Be sure to be up front in answering questions in this regard ,it will save you and the tech time/money in the long run .
Best of luck and have a good day,
:ride:Guscycle

300

That could be carbon tracking. Or a stuck or broken ring.

Yes.
The first guy in Georgia with a 300 had a seizure pretty early on. I don't know that he ever talked about the cause but maybe he will if I call him out. .....Daaaaave? Oh, Daaaaaaaave?

Thanks heaps guys,
Yes the cylinder did get replaced the first rebuild.
Its just about to get looked at, i will let you all know how it goes. i hope its all good, its just unusual what has happen. thanks so much again.

Nick