KX Riders

Maintenance & Technical => KX450F / KX250F => Topic started by: tonysoup on March 28, 2015, 05:54:19 PM

Title: 250f blown top end, damage assesment. Valve guides/head
Post by: tonysoup on March 28, 2015, 05:54:19 PM

Hey guys, got me a kx250f she goes great downhill but uphill is a bit of a problem.

I pulled the head off, prognosis: bad tensioner and slipped timing, piston hit valves, killed piston, bore and head and valves.

my question is is it possible the head may be  salvaged?
you can see 1 valve is bent (looks to be from the valve guide) so im guessing where the valve guide seats it will be damaged.

Is this repairable ? or once the valve guide seat is no longer true its game over for the head?

cheers

Tony (forum noob!)

Title: Re: 250f blown top end, damage assesment. Valve guides/head
Post by: KXDINO on March 28, 2015, 08:25:10 PM

yes it should be repairable , by a head specialist.

Title: Re: 250f blown top end, damage assesment. Valve guides/head
Post by: LukeG on March 28, 2015, 09:30:40 PM

Guides and seat can be replaced or repaired. Cam cap damage is something to look out for depending on how bad the timing slipped.

Title: Re: 250f blown top end, damage assesment. Valve guides/head
Post by: tonysoup on March 29, 2015, 10:25:27 AM

that would be awesome. sweet ill find a head guy.

cams look alright but ill get them tested