Hi guys,need your help please.bike runs fine,recently been making a small tick tick sound came from engine.not good,thought piston slap,bearings,no.touched power valve at bottom with my finger,could feel it was coming from there,as piston moves up and dowm.you can feel it makes contact with power valve,,not good.so,my power valves has never been set(factory paint still on bolts and nuts)so I set the valves of bottom cylinder and it didn't touch anymore,BUT now,my bottom cylinder makes more power than the top one,do I nEed to set top cylinder power valve aswell?you can feel the one exhaust pushes out more compression and smoke than other,I urgently need your help.I want to know:if top and bottom cylinders powervalves are set differently,will the one cylinder put out more power than other one?can powervalve touch piston,and what can happen if it touches.I will apreciate all replies,please need your help

The piston/ring should not be able to touch the power valve under any condition regardless of how it is adjusted.

If it is touching then either it has a large amount of carbon build up on the front, the cylinder exhaust bridge has been relived to much, the cylinder has been plated with the bore off centre (I've seen that before!) or there is wear in the power valve shaft.
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If I have to take the carbs off once more...

To add to Stephen's comments and to answer one of the original questions, a ring touching the valve, could possible catch the ring and cause damage.

My first thought was the valve shaft/valves being worn and having slope, letting the valves shift closer to the piston. Or possible (even worse) the cylinder could be worn where the valve shaft goes and allowing the entire valve assemble shift closer to the piston.

Yes, you need to set both powervalves the same.
Perhaps read this post.
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[color=#808080][size=9]Yes,.. I too know how to waste Time and Money,...

2stroke maniac wrote:....................now,my bottom cylinder makes more power than the top one,do I need to set top cylinder power valve as well? you can feel the one exhaust pushes out more compression and smoke than other

IF, and I doubt that, you can FEEL a difference in power between the two cylinders, you have a bigger problem, than RC valve adjustment.
You can't judge from the smoke. I never found out why, but the NSRs have a tendency to smoke more from the lower cylinder at start up and some minutes after.

PS: There is a bushing in the cylinder for the RC valve and this can wear. I had a cylinder where the bushing was missing. I didn't check if the piston could touch the valve though.
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Poul
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