Motorcycle Repair: 2000 honda xr100r, honda xr100r, punch mark

Question
Hey, Bill
Need alittle more advise regarding my Honda xr100r. Have attempted to crank bike, but no luck. If you recall I told you I had to replace cam chain, cam sprocket, piston rings on bike. I have attempted to kick start, but won't. I have spark at sparkplug (new). Tried ether spray in spark plug hole and still no starting. Any ideas? Clymer trouble shoot section said might be low compression, but I replaced gasket with new. bled gas line, just in case, but like I said, tried ether spray in cylinder and no start with it. HELP!
thanks, rick

Answer
Rick, did you time the camshaft correctly? I think there is a punch mark on the sprocket that goes at 12 o'clock position when the piston is at the TDC (T mark on flywheel). It HAS to be in that position or you will bend a valve. From what you said before, you need to check for a bent valve in the cylinder head. Any time the valves and piston get out of time, the valves will get crunched. You can check the valve sealing by making sure that the valves are closed (TDC compression stroke) and spray some WD40 into the intake port and exhaust port. Easier to do with the head off, obviously.

Turn the KILL switch OFF and remove the plug. Put your finger in the end of the plug hole and kick the motor over. If you don't feel much compression... 150psi is minimum, then you probably have bent valves.

In order to run you have to have COMPRESSION, Fuel, Air and ignition. Sounds like you are lacking compression at this point.

Bill Silver