78 650 wont start

Help! my 78 kz650 just recently will not start. It was running fine about a week ago then just suddenly stopped. i know i have a good spark and i know its getting fuel. i did some compression tests and it was averaging 90psi then i put oil in the spark plug holes and it started averaging around 130psi. Somebody told me that sounds like the pistons rings are shot. but before i spend a lot of money to get that fixed does anybody have any other thoughts on what this could be? or what i can do to get it started?

If not already done, would check valve clearances.

Good Luck!

By stopped running do you mean you were riding it and it just stopped or you rode it, parked it then it wouldn't start. How did you check the spark?
All an engine needs to run is, properly timed spark, compression and fuel. If you have all three it will run.

Will not start as in i drove it around then parked it then the very next day it wouldn't start. I checked the spark by placing the spark plug on the engine. Good news though, i did get it started by putting brand new spark plugs in it but it backfires a lot now. could be a carb problem?

What color are the plugs? When you say its getting spark is it a strong spark ? Was it runing real good before it quit?

Check the Ohms on the coils the input should be 4 ohms and the output 23K. Coils have a way of breaking down and creating more resistance on the output side and sometimes the reading is zero , open circuit. Weak coils will give you some spark, but the plugs will be black like its running rich.

well now i have brand new plugs on them and i'm getting a very clear strong spark. it starts now but i am getting little power to even take off. it takes a while to get up to speed. it was running strong before it quit on me then suddenly just stopped one day