CRF450X valve eating monster

[CRF450XSM]

i converted my crf450x to a supermoto a bit over a month ago and i absolutely loved it, well i did for about two weeks until the valves went:cry: . the majority of my ridding was on winding mountain roads with no highway ridding. my gearing is 13/40

I've herd that the valves on a CRF are not designed for consistent RPM's that are experienced on the streets. and that CRF's are desined for dynamic RPM's that are seen in motocross. and they tighten up pretty quick with consistent high rpms.

anyway i'm looking for solutions to increase the life span of my engine i've herd that by installing Stainless steel valves or the valves out of TRX i can reduce valve ware.

or can get the same result with keeping my revs down, especially at higher speeds...

has any one installed Stainless steel or TRX valves, or got any other ideas.

[weskc35k]

How old or how much work has the bike done?

[CRF450XSM]

thanks for the reply. the bike is an 05 model and up until i converted it to supermoto it only did the occasional weekend trail ride. i disconnected the odometer so i don't know how many miles it's done

[bjr_ew]

Hi Mate,

Put the stainless inlets in from a TRX, they use the same springs, retainers, collets etc. If you've done a few KM's check your valve spring height.

You should'nt be having any problems with the exhaust valves.

I've had the TRX inlet valves in my bike ( CRF450R ) that I use for trail riding and motarding for over 3,000 km now and have only reshimmed it once.

Hope this helps,

Cheers.

[CRF450XSM]

G'day mate.

what gearing were you using for motarding