Motorcycle Repair: Lost compression, intents and purposes, timing chains

Question
QUESTION: I am considering buying motorcycle and have performed compression test which showed that bike has present compression value of 7.4 after cranking etc of starter motor and I know that in the Statistics sheet as stated on Bikez.com it shows that the new condition of this motor should show 8.9 so how far gone is this motor? does this info relate to a %10plus reduction in fuel economy power etc or is their more to it? the motor is only 30,000 km old and my educated guess is that it is nothing more than slightly worn rings which i will be happy to replace or is it possibly far worse as some bikes are known for throwing timing chains etc due to their design.
So i'm looking for a Compression Test value that would allow me to know when I should change rings etc like is a 7.4 rating good or perhaps good to poor for fuel efficiency .......I just need some simple way of knowing when i should really get those rings etc changed for new.

ANSWER: What type of bike is this.. what make model and year... what is the actual compression as tested, how does it run ?
Thanks.
P

---------- FOLLOW-UP ----------

QUESTION: The Make and model of the motorbike in previous question is a Kawasaki KZ250LTD 1981 model(shown on the bikez.com site) assembled in America apparently under license from kawasaki Japan.I have only heard the bike running in a garage but saw very little smoke it started up first go as owner said it would and I couldn't hear much noise if any from the gear box either as i asked about that so the owner put the bike up on the stand(to my horror) and kicked the bike over and started revving it a bit but it sounded okay and no smoke.
So mate I just want an idea as to where you think the condition of the bike is at and I'm told that by listening to the gearbox when running I can get a fair idea of how the state of the bike is.
I'm interested in a reasonably simple way to interpret what a reduction in compression means from a motorcycle that for all intents and purposes appears to be running reasonably well.

Answer
From what you are telling me there should be no issue with this bike with regard to compression. These bikes are bulletproof and fairly seldom do the top ends wear out unless they are totally beat. It could need a valve adjustment and the presence of a slightly tight valve could cause a slight reduction in compression but from your info this shouldn't be an issue. If the compression was way down or zero, then I would be concerned.
Good luck.P.