Z1OwnersClub GB

Man, this project bike is doing my head in. It's fought me every inch of the way. Now that it's running (std airbox and carbs and motor, on 1st rebore) it's smoking a lot and all plugs are black and sooty. I rebuilt the carbs, and it has new float valve assys (from WeMoto, and one leaks ) and I'm pretty sure all settings are correct. I also had the choke plunger seals replaced by someone on here (can't remember his name) who offers that service.

Any ideas? I'm running out of patience (and money) after 6 years...

More info: it starts just fine, doesn't appear to be using oil as far as I can tell, revs OK but is super smoky. The smoke is whitish grey, maybe with a hint of blue.

Have you set your mixtures with a Colortune Plug ?

If not, its well worth buying or borrowing one as its the only way to get them spot on.

Fuel is usually black smoke .
Your greyish blue sounds like oil..

TiBolts wrote:More info: it starts just fine, doesn't appear to be using oil as far as I can tell, revs OK but is super smoky. The smoke is whitish grey, maybe with a hint of blue.

That colour sounds like oil being burnt.
most rebuild parts for sale are cheap Chinese crap, made with poor materials and tolerances. I have used and sold Japanese Keyster parts for may years now with sero issues.
As has been said you do need to peoperly set the airscrews usig colortune or the factory manual method.
Are you certain you have the correct carbs fitted to your bike with the correct jets, needles and slides etc? (At least half of the carbs I service have incorrect internals).
Also have you checked your actual float bowl fuel levels using the clear tube method? (As correct float height does not always mean correct fuel height)
Bad running is not always carbs, but a combination of issues. Feel free to use this article I wrote and go through the checklist:
https://airevalleyclassics.co.uk/badrunning.html

Thanks. Yes I'm sure the carbs are as they should be - I completely stripped them and checked the jets were all as spec and needle height etc. No I haven't been able to check the fuel level in the float bowls - I will have to rig something up with a tube and so on as I don't have the special attachment to screw in.
I rebuilt the motor with new pistons etc due to the rebore; new valve stem seals; checked wear on the valve guides, loads of other new bits in the motor such as camchain, tensioners and so on. It's a worry if it's burning oil - and as it seems to be on all cylinders, looking at the plugs. I will try to eliminate the carbs before taking the top end off again...

Also, having read your article - thanks - will do some more electrical checking with my electrical guru mate. I put a new, pattern wiring harness on and we modified it as it's running a Mosfet rect/reg and a Dyna S ignition. Timing was correct, checked with a strobe. Good shout about the spark plugs; they are NGK but I can't be sure they are pukka.
Cheers

If its just had a total engine rebuild having been rebore, new ring, honing etc the assembly lube burning off and rings bedding in until it clears completely.
Black Plugs. Which make/grade plugs? If they are BR#ES then they have a resistor in the plug. If you also have resistors in the caps you'll get a weak spark and poor combustion. Any plug with a R in the code has a resistor internally. Zpower supply resistor plugs as standard now regardless of what you order.