Compression #'s are down

Well I rode my 77' Kz1000A for a few more miles today. about 70 miles. Pulled the plugs to take a look at them. Still darker than what they need to be even though I turned in the fuel mixture screw a little ( now 3/4 turn out ). May have to c/o the Pilot Jets from 20 to the stock 17.5 ?

I thought I would do a compression check on the bike since now that it's being ridden. Pulled all the plugs and open the throttle al the way. With choke open, here's what I got.

#1 70+ lbs.
#2 65 lbs.
#3 70+ lbs.
#4 80 lbs.

Not too exciting #'s Surprising the bike runs as well as it does.

Now where to start ???

Pics of the plugs,
Steve

No Pictures, but Plugs look identical to Post # 676447 with Plug #1 in picture at the right .

I'd double check that 65 number.
consistency is what really matters. your gauge reads low, the hose is too long, battery is low, blah blah blah and when done who cares.
really doubtful all 4 cylinders are down - more likely the gauge is faulty.

a TRUE 80 psi won't start, as that is an effective compression ratio of like 5 to 1.

The compression tester I purchased is from Harbor Freight with quick connect couplings. It would nice to know if the gauge is inaccurate or the hose too long, I don't know ? The battery is fully charged.

The 65 lbs. of compression in the #2 cylinder if I remember right was a tight valve clearance of .002"

All the other valve clearances where with in FSM specs. .002-.004".

Are you sure the cam timing is right?
Steve

Not sure what you mean by that ? But the cams have never been removed nor has cam chain been replaced. Set static and dynamic timing both to FSM.

I can see possibly that #2 might be a little tight on valve clearance, but could check valves again now that bike is up and running ?

I bought a gauge from Farm and Fleet a few years back I think for 12 bucks .... might be worth that to double check with.