Worried about valve adjustment

[Steve Ruddy]

Ok I just bought a used XR250R about 6 weeks ago and am slowly going through various things making sure it's in good shape and lubricated well. One of the things was to check the valve adjustment. Upon initial inspection I thought the valves where not to specifications so I adjusted them according to the manual. After the adjustment I thought I heard valve noise that was not there before. After taking a couple short rides I definitely heard valve tapping noise so I decided to re check my adjustment. On this second attempt I could not get the flywheel to stay on the T spot it always wanted to roll back clock wise just a little like it was under tension from something. I definitely was at TDC on the compression stroke. I watch the valves all close and put a plastic straw in the piston just to be sure. I went ahead and left the socket wrench on the flywheel and wedge a rag against it to hold it on the T mark and re adjusted. Well that didn't work because it wouldn't star at all after that. So I tried again only this time I didn't look at the T mark at all I only watched all the valves and I just rotated the fly wheel until they all closed and then a little past that point. I made the adjustment again there and now all noise is gone and it runs fine. I am concerned about the fact I wasn't successful doing it as the manual says and am wondering why this is. Any thoughts?

 

[biglou]

It sounds like you're ok, but I know 89'r knows about these bikes and he can confirm. FWIW, I've done XR50 and SDG107 valves by hand, if you can believe that... Basically, ran them tighter than the manual called for, but with just a barely detectable amount of clear space when at TDC. When I set them to spec, they clattered like you described.

 

[Speedfreek]

Is it possible you weren't on the compression stroke and you were on the exhaust stroke while on the T mark,this would have exhaust valve spring pressure tring to rotate the motor which could be the reason you couldn't get it to stay on the T mark. I always found rachets a pain in the butt when tring to locate a mark on the flywheel,try using a wrench or t-handle next time and you'll find it much easier to locate the marks since it won't freewheel past them. :nod:

 

[bikepilot]

Dito to the above. Sounds like you may have been 180deg out. Its not necessarily a bad thing to have some valve noise, especially when cold. I'd recomend adjusting them to spec and going with it. If you get it tighter than spec it probably will not fully seat when hot and you'll burn out the valves and seats in short order.

good luck