Did a valve adjustment

[svrider23]

So I did a valve adjustment on my 07 400XC-W and found both intakes and one exhaust valve to be really tight. The other exhaust valve was in spec. This was the first valve adjustment I've done on a bike, I've done them on cars before and never known them to tighten with wear. Is this common? Why would they be like that? Oh, the bike has 30 hours on it. I also noticed one of my header springs was missing and when I put my kick stand down after I finished everything that spring broke, ***!

[L-vie]

On over head cams it is common for the valves to tighten up because the valve seats deeper into the head as they wear in. The intake valves are pretty soft.

Valves should be checked every 15 hrs.

On new motors this is real important.

[WR250F Captain]

the seat and valve both wear and that is what makes the valve sit higher in the seat, which closes the lash between the bucket and the lobe.

this is normal, especially on Honda's, and imho least likely is yamaha/XR(honda exception to the 4 stroke valve), but haven't had much experience with KTM so...

[Dave Hopkins]

The 07 400, one of the last of that RFS engine has soft stainless intake valves and need to be adjusted every 15 hours. At the top of this page is some "pinned" "FAQ" articles, mine on valve adjustment should saveyou some time. If it where mine I would set the exhaust side at .oo5" (spec) but intake side I would set at .006". This will allow you to adjust much less often, maybe 30 hours as the exhuast moves very little and the intake is known to be closing

[svrider23]

I know I should've already done the valve adjustment but I was having so much fun riding and honestly I was a little intimidated of doing the adjustment. I talked to a friend and he said his valves usually loosen but they have tightened a couple times. So could the valves being loose or tight tell me anything? Like I need to clean my air filter more often? I clean it every ride, maybe I need to switch it during a break in the day. Or is it just normal wear and I shouldn't worry much. Also the feeler gauges I used were really difficult to work with. There is a video on Youtube and the one he used looked much better... It was bent on both ends. Where could I get that one?

[WR250F Captain]

your valves shouldn't be getting looser, unless you bent the stem, and it doesn't seat right. or the manufacturer put too small of a shim and it came lose.

the valve spring will always push the valve up, so it shows the wearing of the valve and seat by getting closer to the lobe.

some companies also put soft springs in, like honda, which makes the valve bounce on the seat and getting 2-3, heck who knows, times the wear

this is why Yamaha valves last so long, they are coated very well to resist wearing, they have strong springs for a very high reving motor, and have been doing the same motor for 9 years. Honda just now is getting it right, which is sad

if your airfilter allows dirt to go through your engine, your valve will beat the dirt into the seat, and as well all know, valves turn, and the seat will start to sand down your valves.

motion pro makes some really nice feeler's and I got a set of them. the have a handle and are bend to fit in tight spots, not expensive at all either

I know I should've already done the valve adjustment but I was having so much fun riding and honestly I was a little intimidated of doing the adjustment. I talked to a friend and he said his valves usually loosen but they have tightened a couple times. So could the valves being loose or tight tell me anything? Like I need to clean my air filter more often? I clean it every ride, maybe I need to switch it during a break in the day. Or is it just normal wear and I shouldn't worry much. Also the feeler gauges I used were really difficult to work with. There is a video on Youtube and the one he used looked much better... It was bent on both ends. Where could I get that one?

[L-vie]

Also the feeler gauges I used were really difficult to work with. There is a video on Youtube and the one he used looked much better... It was bent on both ends. Where could I get that one?

I perfer to use the 1/6 method for setting the valves. It easier and I think its more consistant. I'm sure some will disagree.

I believe there is a video that explains the 1/6 method when adjusting the valves. Look in the "Sticky" section.

[Cycle_Path]

dont feel bad. I did my valves on my 525 recently. They where all compltely closed up. No wonder it was getting harder to start.

[slideways11]

I perfer to use the 1/6 method for setting the valves. It easier and I think its more consistant. I'm sure some will disagree.

I believe there is a video that explains the 1/6 method when adjusting the valves. Look in the "Sticky" section.

Plus 1 on the 1/6 method. Easy and accurate.

[Swike520]

Since everyone on this thread is talking about valves i am in the process of rebuilding my engine off a KTM 520 MXC. It was having a VERY VERY hard time starting for the first time in the beginning of day. After that it started every time. i Noticed it seemed tired. So i was going to check the valve clearance they were tight even with the set screws all the way out.

So i then realized WOW this is not good. So i pulled the head thank god i did. If i were to ride another year on these valves they would of been pulled apart.

So my predicament is that i need to know what the valve angles on the head should be to regrind the seats on the head. They are still good. I would greatly appreciate it. I would also like to know how to align "time" the crank and cam when i put it back together. Thanks

-Poot

02 KTM 520 MXC

1981 Kawasaki 440 LTD

[WR250F Captain]

just get new valves and seats and have them done.

once valves start to wear, the wear faster and faster. well, at least thats what Ti valves do because of there coating

[Dave Hopkins]

Swike

I do lots of valve work on these and they are all at 45 degrees, always use new valves and recut the seats to match

Since everyone on this thread is talking about valves i am in the process of rebuilding my engine off a KTM 520 MXC. It was having a VERY VERY hard time starting for the first time in the beginning of day. After that it started every time. i Noticed it seemed tired. So i was going to check the valve clearance they were tight even with the set screws all the way out.

So i then realized WOW this is not good. So i pulled the head thank god i did. If i were to ride another year on these valves they would of been pulled apart.

So my predicament is that i need to know what the valve angles on the head should be to regrind the seats on the head. They are still good. I would greatly appreciate it. I would also like to know how to align "time" the crank and cam when i put it back together. Thanks

-Poot

02 KTM 520 MXC

1981 Kawasaki 440 LTD

[Dave Hopkins]

2007 EXC is not Ti, as I stated in a prior post they are stainless steel, 08 a somewhat soft stainless on the intake side

For 2008 the EXC has Ti

just get new valves and seats and have them done.

once valves start to wear, the wear faster and faster. well, at least thats what Ti valves do because of there coating

[WR250F Captain]

2007 EXC is not Ti, as I stated in a prior post they are stainless steel, 08 a somewhat soft stainless on the intake side

For 2008 the EXC has Ti

I didn't mean to sound Like I was saying they were Ti valves.

I was saying coated valves wear much faster once the coating wore off.

sorry, if I wasn't clear :thumbsup;