kz440

hello i just bought a 80' kz440 and wanted to kinda restore it i checked the compression and it was 110 and 100 and i was wondering if that was good or bad compression and if it is bad could i do anything to raise it without rebuilding the engine? thank you!

Did you set your valves? Sometimes the rings get stuck. Put a couple drops of oil in the cylinder, turn it over a couple times, and check it again.

no i have not set the valves yet i had planned on doing that very soon are those pretty poor numbers?

For a 440, i'd think those are pretty poor. I think they should be 160+ but that is a hot number.

If its an air cooled/old engine, it has very large engine clearances. only hot compression numbers should be fairly considered.

Make sure to have the bike hot, twist throttle wide open, then crank engine until compression no longer rises.

Should only take about 4-5 revolutions normally.

Good luck - remember WideOpenThrottle is critical.

Cheers.

PS. If those are in fact accurate numbers, then you will be tearing into that engine. Get the manual, it pays for itself first time you use it!