checking used engine

Hi, guys i am about buy a used kz900 motor, the compression is good,it spin over freely when hooking a battery to starter,is there any other checks that i can perform to verify the motro is good ( the motor is out of the bike so we can not crank it.) thanks in advance for your help.......

how do you know if compression is good if you cant crank it?if its got oil in it push down on the rear of motor while you crank it to keep it from bouncing and listen for clunking

I would check compression with a compression gauge. The 903 engine has a kicker which can be used, even with the engine out of the bike. You can also turn the engine over if it has a starter... just hook a bike battery to it. If you are looking for an engine that doesn't need to be rebuilt, the compression check is about as good as your are going to get... I would just assume the engine will be rebuilt (I rebuild all the engines I use as a matter of course).

thanks,alots guys,i was thinking about having the head rebuilt and replacing the pistons rings,i'm kinda afraid to venture pass that point,the transmission gears looks a little intimidating,again thanks for the help

Post edited by: trab, at: 2008/03/08 08:29

I'd ask to pull the valve cover and wiggle the cam chain idler sprocket as well as what the others say. A sloppy idler sproket will be an indicator for the other sprokets/rollers associated with the cam drive.Keep in mind the engine can't be warmed outside a frame so your compression values could be low. This check is usually performed on a hot engine.

definately,im thinking more along the lines of a fairly even number across the board to get an idea how solid the motor is;)