Z1OwnersClub GB

Did a compression test on the Zeb last night after a short ride round the block so it was warm. Not hot but hot enough for me to burn my fingers on the plugs Took the carbs off for the test and got:

cyl 1: 115 PSI
cyl 2: 110 PSI
cyl 3: 115 PSI
cyl 4: 115 PSI

Has been burning off oil when starting and showing signs of oil on the plug in cyl 1, hence I tried the test. Looks to me like it's worth lifing the head and checking the valves seals and head gasket. Also adjusting the clearances at the same time.

Bike has done 45K miles but supposed to have had a set of barrels last year after a cam chain tensioner went. Barrels were off a 25K bike but I couldn't see any evidence of rings being replace in the paper work.

115 psi seems a bit borderline to me; wondered what every one else thought? I seem to remeber being able to get stepped rings if reusing old barrles and pistons; does this sound right ?

Don't want to have to go the whole hog of new pistons etc if it's not necessary; since I'd rather spend the money on better brakes and getting the wheels rebuilt at the moment.

I would always do valve clearances first after the improvement in running I got.

Try putting some light oil down plug hoels and re-test see if figures increase much, if do suspect rings, would check valve shims and if ok look at valve seats etc,115 is ok seem to recollect service limit is 100 psi,,,cheers Pauljac

Bit on the low side...... Nice & even though

If the bike ain't smoking too much... and running OK, I'd leave it, could get another 10k miles out of her

That's what I was thinking. Maybe after doing the head it will be better and I can run it for an other year.

Runs OK, with no smoke after it's warm. Pulls OK if a little lumpy below 2000 revs but I think that might be clutch

my smokes like a chimmney but runs okay leave it to the winter then fix it