Fitted new needle jets and needles, problem sorted runs like new. thanks to jphaynes669 and njwmct for your spot on advice.

Checked the chokes are shutting off they are ok, I removed one of the needle jets and it is badly pitted so i have orderd genuine Mikuni needles & needle jets from Allens Performance, I will let you know the results.
Thanks for all your help.

I have stripped the carbs down (again) and the needle emulsion tubes are pitted, the keyster kit at NRP includes emulsion tubes are they not good quality ?

Thanks for your help I think my next step is Keyster carb kits from NRP and a colortune kit.

That was my thoughts that it could be the pilot system, I have tried the standard mikuni 17.5 jets ultrasonic cleaned, the pilot airways and drillings are clear and new 17.5 pilot jets from Z1 Enterprises with no change.

I have a bad flat spot off idle on my Z1B starts ok, runs ok, ticks over ok, as soon as you touch the throttle off idle the motor almost cuts out and then picks up, spark plugs are sooty I am at my wits end tried everything New Dyna coils and ignition New leads and caps Denso plugs New carb inlet ru...

Just been out for a run on the Z1b with a rebuilt engine, noticed oil weeping from the head gasket joint at the front LH side, I tried Re torquing the head but no luck, should I have had the head skimmed before re build or maybe used gasket sealer on the head gasket. Thanks for any advice

Just replacing the wiring loom on my Z1B and i notice the handlebar switchgear wiring is very brittle, i am thinking of new switches from Z power or E bay, i know these are reproductions but are they any good ? can i swop the new internals into my old switches ( just to keep the date codes) Regards ...

Adrian Flux insure modified bikes and cars

I think there are o rings that size under where the choke mechanism screws into the carb body

Just done the relay mod on my z1b with dyna ignition and coils, the difference in the strength of the spark is amazing.

I know a lot of people don’t agree with powder coat on this forum but I have had many of my bike frames powder coated in the past Guzzi le mans, Norton Commando, Triumph and my z1b all at Triple S at Bingley and the results have been superb they only do motorcycle parts not garden furniture like s...

I m just jealous. there’s something about being in your nice warm shed the radio playing, tinkering with your bikes. Best place in the world

Compared to my shed that’s an alpine lodge

Just done the same with my 4 into 4s Blackfriar paints do half litre tins of heat resistant black paint for BBQ's and stoves for £10. The rotted Z1 exhausts ive seen are usually rusted through at the very ends where the baffle bolts in, this part is double skinned and its important to get some pain...