I have taken the lever out when it was running and had same noise.
Pulled the lever out of rocker head.
I'll loosen it up tomorrow and get a video of the actual start.
thanks i really appreciate the help

Two videos
> shows a cold start. After 45 seconds you can hear the clicking getting stronger. Its seems to get louder with tightening of decomp cable. XT 600 Top end noise - YouTube

> decompression cable: I start i think mid adjustment then tighten. Then I loosen up. https://vimeo.com/77238617

If i do need to take the head back off I will be looking at thread problems with the bolts. Can some one please give me advice on what you have done with over torqued head bolts

Also I have 2 frames, good one to be painted (if i can sort motor out) and one I'm using now (in video). This frame has a weld to keep right foot peg assembly on. It will prevent me from taking off RH cover. Very crappy sloppy weld. Until I switch to other frame I am stuck on that side. Goal was to rebuilt suspension etc 1st

Well that was some great videos and showed the difference with the decomp. It doesn't look like that is whats going on as long as it's loose enough. In the first video when you start it, I thought that was normal sounding, at least how the 2 of mine sound, you can here some noise but is mostly drowned out by the exhaust, however I think it had more to do with how the sound was being recorded because it was louder later on.
For the threads in the heads, if they are not stripped now, they should be fine, just try to find some longer bolts to grab more threads if possible and as long as the bolts don't bottom out. If the threads are coming out, then there are helicoil kits where you drill out the holes then rethread and insert a helicoil(red loctited) to restore the correct size threads.

Yes it sounds very well for the 1st 30 seconds. Perhaps I can only drive in 30 seconds intervals.
What I'm trying to figure is what the heat is doing. There is thermal expansion and there is thinner oil. Perhaps I shoot some heavy 80 weight oil in.
Man I really don't want to pull the head again and be back to square 1. I'll take another stare at the lifters. :offtopic:

Do you have 20W-30 in it now? that what I run, for under 45F I'll switch to 10w or 15w but mostly run the 20w.
I'll be willing to bet there is one rocker that is either a little loose on its shaft or sub rocker that is out of spec,
. Did you try the oil squirt gun and heavy oil, when the bike is running, unscrew one front cap at a time and squirt a bunch of oil over each rocker to see if the noise suddenly quiets or changes when the oil hit one. you would then know where it is coming. If nothing chages, then it has to be something deeper. Try to hit all the rocker pivots and where they contact the valves. Cam lobes also, I will make a mess, but may end the wondering.

I am running 10-40w its a 50/50 half synth

I think you are right. The exhaust right side rocker had less resistance then the other 3. There wasn't much difference in movement side to side between any of them. The exhaust right side rocker perhaps has to much play in it. I didn't measure it and regret that now. It just didn't seem to be an obvious problem and i was feeling it was a problem with the decompression cable.
Example: If i was to lift the rockers and let them fall, 3 of them had slight resistance to the fall. The right side exhaust would just fall.

To me at the time it seemed that wouldn't indicate a problem as when the motor was running that would be a non matter. Was i wrong.
I just don't know if i could be damaging the motor if I run it.

What you describe about the rockers not falling on their own(normal and good) and the one is looser could be what is the issue. If it was mine, I would just run it (as long as it wasn't annoying badly). The possibility of it being rocker related and not something more "serious" is so high that it's worth it to run and see if anything breaks or if it gets louder yet. I'd just keep an eye on the noise and pay attention to any changes. If something is going to fail it will do it fairly quick, otherwise not for a long time. Along the way maybe keep an eye out for a new rocker and shaft, if somewhere along the way the cover needs to come off, replace it then.

Thanks!!

tried shooting some oil in but it was just too messy. So oil is being pumped.
Feels like the the rocker is hard to adjust. Like it is missing some damping somewhere if that makes sense. This is the right exhaust.
I think since the rocker is perhaps looser that's the issue. As I said earlier, mimicking the sound by self tapping the rocker seems to copy the sound very closely.
I am going to ride it and I'll look at the rockers when I switch frames.
Thanks for all the help
greg

If that is what's doing it I can send you a good shaft and rocker setup. I have about 6-7 topends to choose from.

Hey JJrider thanks for the offer, if you can spare just let me know what you would need.
I ran it for about 30-40 minutes today, noise very consistent. No increase. Besides some oil leaking from some over torqued bolts and a carb stumble well it ran better then i thought it would.
I am going to start a new thread on carb stumble :(.

I have a rocker cover with several rockers and shafts still in it but the cam journals are shot. I'll clean it up and take a look at clearances , should have enough extras in there in case you need to change more than one. I'd say a few bucks more than shipping and it's yours. Where you located at? That may be the deciding factor whether it's worth it or not.

Here's some pics of that cover and rockers. After washing it all down in parts cleaner the rockers all moved with resistance and tight. The pads cleaned up pretty good, not the absolute best, but easily usable. The one by the bad journal I wouldn't use but the shaft and wave washer is good. I'll know more tomorrow night as far as the carb parts.

Update
over 400 miles and no changes. hard to put many hours as winter has been rough here.
Same sound when warm, has not increased. Have run for over an hour at a time with no issues. Burns no oil.
Still don't know how confident i should be on longer trips away from home.
Greg