Need opinion on compression test

[GnR]

Well I just picked up an '03 SE on the weekend, it's in pretty good shape overall, just needs a little tlc. The only compression tester I had could only be threaded in half the length of the plug, but I figured what the hell and tried it anyway. It read a touch under 115 in both cylinders (sea level). Is this reading completely off? And if it is would the reading be higher or lower with the proper length attachment? By the way this is my first Banshee, and first time owning a two stroke machine. I'm stoked on it. :biggrin:

[deckheight]

Different compressions gages read different. A short threaded end will give a lower reading than a longer one, as will a gage with the schrader valve near the head rather than down near the engine. In general, it is often more important that both cylinders are "balanced" (read within 5-10psi of each other) than wether or not they blow a specific number. If the bike starts easy and runs good but your still worried about it I would probably check it with a known accurate gage before visually inspecting the bores.

[LiftdT4R]

The above poster is right, different gauges will give slightly different readings (but it shouldnt vary a lot). 115 is decent assuming your running a stock head. I think off of a fresh rebuild you should be 125, so even at 115 you have plenty of life left. When you get down around 100 you should be looking at rebuilding.

[GnR]

Thanks for the input guys. Ya it's running a stock head so comp is pretty good considering its never been rebuilt. Should get me through this riding season and then I plan to send it away for some port work.

[GrMeyer]

my compression gauge i put it up to my air compresser and set the reg to different PSI to see if they match...easy way to see if your gauge is close or not