Tight KTM intake valves?

[pete.ktm]

hey

adjusted my '06 ktm 450exc valves and unless i totally screwed up the cam positioning the intake valves had no 'wiggle'. hard to start before the valve adjustment, easy as after so i'm sure i got the adjustment right.

was desperate for a ride so rode that weekend, bike ran fine maybe a fraction hot.

since then i've read up a bit more on the ktm intake valves and would prefer not to destroy my engine.

anyone had the same and recommend the best course of action i.e cheap/good place in wellington to get it looked at? kibblewhite valves? etc

bikes just coming up to 300 hours so maybe a good time to get a few things checked out?

cheers

[CrazyFrog]

The KTM EXC RFS motors from 04-07 are pretty reliable and should last a fair while so long as you do regular oil changes, every 10-15 hrs, and valve clearance checks every 25-30 hours, as per the owners manual maintenance recommendations.

Valve clearances must be done when motor is totally cold, otherwise clearances can be altered by engine temp. Make sure the intakes have at least 0.10mm clearance, but they can be opened up to a max of 0.20mm. Factory setting is 0.12mm.
Exhaust valves generally don’t move much and give you issues, it’s the intakes you’ve gotta watch, they have a tendency to close up. Being hard to start is a good indication intakes are closing up.

If you’ve had 300 trouble free hours then that’s a good thing, and it’s possible that the intake valves have reached the useable end of their adjustment, in which case, yes replacement is the only option. Any shop mechanic worth his salt should be able to verify this in 10-15 min, the time it takes him to check clearances.
If you are replacing them, Kibblewhite valve sets are the most trusted option, go for stainless valves, not titanium as these cannot be re-ground. replace the valve guides, and springs at the same time, and while you’re in there, replace the camshaft bearings too.
The KTM manual recommends at 100hrs do piston change, crank main bearings, conrod bearing, balancer shaft bearing etc, pretty much full rebuild territory.

Most EXC owners know they will do well in excess of 200hrs before these NEED to be changed, depending on what sort of life you give the bike. The harder you ride it, the more likely it’s gonna need more work. If you’re easier on it, trail riding as compared with enduro racing, then 300+ hours is not uncommon before needing any sort of motor work.
I’ve got a '06 525 EXC, and have had no issues apart from intakes closing up a tiny bit. I’ll be doing cam bearings at 200 hrs, the rest will be done at 300 hrs.
My advice is, do the valves and cam bearings. The rest? How deep are yer pockets??

[pete.ktm]

My advice is, do the valves and cam bearings. The rest? How deep are yer pockets??

took the easy/safe way and it's going into TSS this thursday.

will def do the intake valves and cam bearings and will get TSS to take a look at the piston etc while it's apart.

cheers crazyfrog.

[pete.ktm]

just on the off chance that anyone else is in the same situation...

Bike went into TSS and the verdict was that the intake valves were completely rooted, another ride and it probably would have detonated. good timing.

Since it was being opened up they took the barrel off to check the piston, looked good for 300 hours but just to be safe i replaced it. also replaced cam chain, cam bearings, water pump seals.

A piston was going to be 3 weeks from Austria so supplied one myself from e-bay along with a Kibblewhite intake valve kit also from e-bay.

Cost was just under $2k with a couple of other things done.

Sounds a lot but it was the only major work done on it in 4.5 years and 220 hours.

Went to Halcombe last Sunday and it was sweet, cheers to Paul from TSS.

Now I just have to fix my mates '08 450exc i borrowed while mine was in the shop after it started to piss out blue smoke.