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Z1 carbs help

Posted: Tue Apr 17, 2018 8:20 pm
Author: pht9
I've recently stripped my carbs to clean them, and noted that the needle jets (5J9) are set at position 4, where the manual says position 3 (for a 73 bike)

What will be the difference with the two positions (richer or lean) and at what part of the rev range/throttle opening ?

I also note the new main jets that came in the carb kits are 113, the originals fitted are 112.5 - again, what can I expect from the difference ?

.....and if anyone has any recommended settings that deviate from factory - please advise

Bike is standard with standard airfilter and airbox/exhaust etc

Re: Z1 carbs help

Posted: Wed Apr 18, 2018 8:38 am
Author: chrisNI
Does it run ok?

Re: Z1 carbs help

Posted: Wed Apr 18, 2018 9:29 am
Author: warren3200gt
The higher the needle, ie the lower the clip, richens high revs. The lower the needle, ie the higher the clip, weakens/leans the high rev range.
Where it needs to be depends on exact exhaust you have and exact air filter, and fuel quality.
As Chris says, if it runs ok leave well alone.

Re: Z1 carbs help

Posted: Wed Apr 18, 2018 3:29 pm
Author: pht9
Not run it yet, as it had been standing sometime

Needed to rebuild front caliper as it was sticking and strip carbs as they were pretty crusty

My observations were during the strip

The information provided is certainly useful, but agreed will have a better idea when I give it a good run

I was hoping to get them ‘right’ first time but guess thats pretty rare !

Re: Z1 carbs help

Posted: Thu Apr 19, 2018 10:59 am
Author: warren3200gt
Question is then, was it running ok before it was left standing?

Re: Z1 carbs help

Posted: Thu Apr 19, 2018 6:42 pm
Author: pht9
warren3200gt wrote:Question is then, was it running ok before it was left standing?


Not really, as its not really been used for the past 3 years - so poor fuel would also factor in

I did speak to the previous owner that claimed it was a bit rough when cold, but then settled down when warm

If the opinion that the factory settings are as good as it gets, then I'll revert

Was hoping that someone had experience and could advise if my deviation of using 113 mains and the needle jet one position different is enough of a change to affect the running considerably