Z1OwnersClub GB

Have a 1975 Z1b which oils the plug on No 1 and refuses to run on that cylinder. Have done valve stem seals, lappped valves, replaced gaskets, skimmed head, honed barrells and replaced rings. There does not appear to be any cracks in head or barrel liners - any thoughts?

my thoughts are, if you can do all that to your bike, i think you should be able to manage to say hello and introduce yourself on the new here page. no offence tb.

Have you swapped plugs & leads to make sure

Valve clearances checked

2 Do a compression test or leak down test to rule out bent valve or tight valve shim clearance.
3 swap left coil for right coil and vice versa.
4 Open the pilot screw on number 1 by two turns and see if it fires there after that.
5 If it does; remove pilot screws and spray through with carb cleaner, hyper clean or blow through with air line. Filling eack drilling will show whether they are blocked by draining or not as the case may be.
6 Swap lead number 1 for lead number 4.
7 Swap cap number one for cap number 2,3,or 4
8 If after market filters; swap filters left to right and VV.
9 Measure voltage at coils.
10 Measure voltage at battery.
11 Remove carbs, strip and clean.



AL

What make plugs?

Had similar fault on my Z1B, ended up fitting new valves, stem seals and valve guides, my guides were loose in head and allowing oil around the outside as well as down the valve stems- worth a check mate.
You can get oversize guides from Debben Performance if you need em.

Seen this too. Turned out to be rings. Rings vary in thickness by as much as 20 though and thats more than enough to let oil past the compression rings. If your stripping down its worth checking this out.