I have a 98 KLX300 with an 80mm piston, pumper carb and Pro Circuit exhaust. When I bought it, it smoked like crazy (white), but ran fine. I only rode it a few hours one time last summer and it developed a little bit of a clicking sound. I figured it needed new head gasket/rings and a valve adjust. So I opened it up over Christmas and replaced the rings the head gasket and also adjusted the valve clearance to within tolerance. Everything looked pretty good in the top end (cylinder was smooth and valves moved freely).
When I got it back together it didn't smoke at all, but it is still making racket at lower RPMs. I re-checked the valves and all but one are right in the middle of the range, with one exhaust being just a bit on the plus side (.010 in clearance). I don't think it is an exhaust leak, but haven't completely ruled out anything.
It kicks over easily and has plenty of power, starts after a kick or 2 (2 if choked when cold - 1 kick when warm), but I am concerned about the clicking sound.
Any ideas? Last night it occured to me that I could have the timing off by a tooth. Does anyone know if it would even start in this config?
FWIW - when I put it back together the IN line was perfectly parallel to the cylinder head, but the EX line was just slightly tilted upwards toward the front of the bike. If I try to move the exhaust cam a tooth over the EX disappears below the line and is slightly tilted downward so it wasn't completely clear cut as to what the correct position was.
Thanks in advance for any advice/pointers.