Thanks

[Old Rider]

The Z 900 had been leaking oil from the cam chain adjuster and a mobile mechanic had "fixed it", but then the bike sounded like a bag of hammers being thrown around when it was running and he'd given up trying to get it to run properly, after also messing up the ignition timing.

Great pictures  
Nice z900  that timing issue sounds familiar.My kz900 started running bad a few weeks ago it started to backfire like a shotgun and lost power .I took off the valvecover to check and found the camchain had jumped 1 tooth.The camchain tensioner on theese bikes is not automatic,and will have to be reset reguarly by losening the bolt on the side and then tighten it again.I first thaught the po owner / owners had overlooked that and i reset the tensioner and timing.Then i took a ride again and it happened again plus one of the coils melted there was 3 big bubbles underside of one of the coils and smelled electrical burnt wiring.Then after some fiddling with the timing i found that it is not possible to set the timing 100% right because the chain is probably stretched and timing chain sprockets sliders and rollers are worn plus the spring in the tensioner is weak.When turning engine over with a spanner on the crank nut the intake cam is making a slap so the chain jumps .Been lucky because no valves are bent .So now i have teared the engine down  for a total rebuild good to have something to fiddle with during winter  

[Millietant]

Yeah, I think the mechanic has just taken out the tensioner, put a load of silicon gasket sealer around it and put the tensioner back in - and the chain jumped on the sprocket.

When I checked it, the timing mark was 27 pins away from the exhaust sprocket set point, instead of 28 pins. The ignition timing was also completely out. An electronic ignition had been fitted and the set up instructions were a bit ambiguous. I would have thought any competent mechanic would have known how to set it even without the instructions (I did and I don't class myself as a competent mechanic) but that guy couldn't do it.

Anyway, all's well that ends well, and the owner was very happy after we handed it back and he'd put 100 miles on it 

[Old Rider]

That is the same as on my bike when timingchain jumped, it was 27 pins to the 28 mark on intakecam instead of 28pins.
There is also an electronic ignition fitted on my bike it is dyna-s .Since one of the coils melted i started  thinking maybe it has something to do with the dyna-s
ignition so i have bought a Boyer Bransden igniton set with microprocessor and coils included.I have not installed it yet and after some reachearch i found both good and bad things about it so not sure i will install it.Judging from the wiring terminals im not impressed .I may install the oem points to keep the bike 100% original.That mobile mechanic that "fixed" the z900 you worked on should a least carry some gasket material in his car and make a new gasket instead of using silicone.

[Millietant]

That's the same system as is on this Z900. It seems to work really well now, just had to read the instructions carefully and I think jump from Step 16 to the 5 separate steps at the end (can't remember exactly as I've slept and been drunk since I did it  ).