low compression

well finally got a chance to look at the bike an c what's going on with the motor??? well low compression in all cylinders going like this 90,100,100,110,105. guess its time to tear bike back down after finally getting it together an finished this past June!!!!

before u tare it apart . try to determine whether it is valves, rings or both. do a leak down test.
unless u just have a lot of miles on it and its time for a complete job , then carry on.

Ok, ill be the smartass. Do you have 5 cylinders?

etbike3135 wrote: Ok, ill be the smartass. Do you have 5 cylinders?

just rebuild the best ones. lol

ops sorry bout that. im not actually sure how many miles the speedo says 20,000, but it suppose to have been redone an built sum.so i will do a leak down to c???

Valve guides are the culprit on a lot of the early 900's. I just worked on a guys who had 90% leak down in one cylinder, right past the exhaust valve. He was still driving it too! You wouldn’t believe how blown out the guide was, could have almost stuck 2 valve stems down that hole.

that's pretty bad that would have to b the worst I've seen lol. i know im getting sum smoke out the pipe when i get on it. lost the big pull on the gas.

How are your valve clearances?

79kz1000* wrote: well finally got a chance to look at the bike an c what's going on with the motor??? well low compression in all cylinders going like this 90,100,100,110,105. guess its time to tear bike back down after finally getting it together an finished this past June!!!!

Which bike are you referring to, the KZ900? Iff so the service limit on the compression is 85 according to the Z1-manual that I got off this site. With no more than a 14 lbs/sq in. from the highest to lowest reading. But my Clymer generalizes and says between 130 psi and 160 psi. And most people here quote the higher numbers. So I am unsure with this specific bike what the correct compression is. If you believe the manual below, then you are within service compression and don't need to rebuild. Hope someone here can clarify what is correct for your bike.

it's the kz1000 ltd b3

Also depends on your compression gauge. Has been posted lately that the Harbor Freight compression gauges read low.

Have you hade the cam chain off anytime? timing coud be off if it has. Make sure and I'd also check clearences too like Roy said while in there.