when adjusting the valves how important is it to be at TDC on the compression stroke? i was under the beliefe that the piston was at the same position weather you are on the compression or exhaust stroke? they seem to adjust fine last time i did them. maybe i just got lucky? thanks.

 

When the piston is at the top of it's travel, it can be at it's compression or exhaust stoke. Only the cam determines whether which one it is. You want to adjust the valve when both of them are closed (compression stroke).