My 03 Honda Rancher 350 has always ran good. One day I stopped for lunch then it wouldnt start. Checked fuel,spark,etc. all ok, then checked compression, NONE, i'm thinking my comp.release is stuck open. Where is it, how do i check it?

 

as far as i know, the 350 does not have a compression release.

If you have low compression, add a little oil to the cylinder through the spark plug hole and check again. If the compression comes up significantly, you have worn rings.

if not, check your valve adjustment and adjust as needed.

You could also have a blown head gasket or a cracked head.

you could use a compression tester fitting and put shop compressed air into the cylinder and see if it leaks out the intake, exhaust or the crankcase breather. Spin the engine so it's coming up the cylinder on the compression stroke (not the overlap stroke) and put shop air in. The air will push the piston back down to the bottom of the compression stroke and any leaks you will be able to hear. Intake and Exhaust would be those valves respectably, and out of the crankcase breather would also mean worn rings.

 

The owners manual mentions the compression release is activated when starting.