I took the bike for a spin past the local dirt bike mechanic and he had the opinion that the tensioner may be the issue, given that I had previously inspected the valve clearances AND that there are known issues with the tensioner on these motors. NO power loss noticed. It is a pretty heavy duty HYVO type cam chain on these bikes. I'm going to re do the valve clearances again, but there are plenty of videos on line about that.
The factory manual recommends the engine be on TDC COMPRESSION when the clearances are checked. Also, I saw someone on You Tube do it...The reason would be to keep from changing the cam timing, I suppose. If the valves are being pushed down by the cam, they would end to push on the cam and thus affect the position of the cam chain drive sprocket and the cam timing. Does that make sense?
How does the timing change? Both the primary gear and the camshaft stay in the same position, only the chain gets loose a little bit. Maybe the chain will be too loose and the camshaft will move a link? I don't think it's realistic.
@@ronenfe I think to keep the tension on the chain on the same (tensioner) side when changing the tensioner, as if the slack in the chain moves the other way (to the other side?) the chain run could be different? Once I zip tied the cam gears to the chain on my KTM 390 (had to remove the cams to do the shim clearance) and the fuckers still moved relative position on the chain...!
Hi! How did you diagnose the poor tension, just by the engine sound?
Are there other indicators like power loss or anything else?
I took the bike for a spin past the local dirt bike mechanic and he had the opinion that the tensioner may be the issue, given that I had previously inspected the valve clearances AND that there are known issues with the tensioner on these motors. NO power loss noticed. It is a pretty heavy duty HYVO type cam chain on these bikes. I'm going to re do the valve clearances again, but there are plenty of videos on line about that.
Why the need of top dead center for replacing the tensioner?
The factory manual recommends the engine be on TDC COMPRESSION when the clearances are checked. Also, I saw someone on You Tube do it...The reason would be to keep from changing the cam timing, I suppose. If the valves are being pushed down by the cam, they would end to push on the cam and thus affect the position of the cam chain drive sprocket and the cam timing. Does that make sense?
How does the timing change? Both the primary gear and the camshaft stay in the same position, only the chain gets loose a little bit. Maybe the chain will be too loose and the camshaft will move a link? I don't think it's realistic.
Yes maybe it's possible it will move if the chain is too loose.
@@ronenfe I think to keep the tension on the chain on the same (tensioner) side when changing the tensioner, as if the slack in the chain moves the other way (to the other side?) the chain run could be different? Once I zip tied the cam gears to the chain on my KTM 390 (had to remove the cams to do the shim clearance) and the fuckers still moved relative position on the chain...!
You don't need to do this at tdc