Thanks for your offer of help Stu.
I’ve pm’d you my mobile number
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Cannot get float heights correct
Moderators: chrisu, paul doran, Taffus, KeithZ1R
Re: Cannot get float heights correct
So today I called Zpower to ask for advice on the problem and non original float valves.
They said they have sold loads of pattern ones and never heard of problems.
I was gonna order one original valve as a test for £31. They said they were about £50 each so their site was wrong. Later today the price on their site changes to £52.95 each for original float valves
I’ll just have to try again with what I’ve got.
One question I cannot find a consistent answer for.
With the clear tube float height method, the rough picture in the Clymer Manuel makes it look like it should be 1/8 inch below the bottom of the carb body. When the bowl screws onto the carb body it goes up inside a flange. So is the 1/8 measurement from the bottom of the carb body, from the top of the bowl or from the carb body surface above the bowl gasket.
They said they have sold loads of pattern ones and never heard of problems.
I was gonna order one original valve as a test for £31. They said they were about £50 each so their site was wrong. Later today the price on their site changes to £52.95 each for original float valves

I’ll just have to try again with what I’ve got.
One question I cannot find a consistent answer for.
With the clear tube float height method, the rough picture in the Clymer Manuel makes it look like it should be 1/8 inch below the bottom of the carb body. When the bowl screws onto the carb body it goes up inside a flange. So is the 1/8 measurement from the bottom of the carb body, from the top of the bowl or from the carb body surface above the bowl gasket.
- warren3200gt
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Re: Cannot get float heights correct
http://www.allensperformance.co.uk/shop/
I think z power are taking the piss.
I always set mine 3mm from the mating surface.
I think z power are taking the piss.
I always set mine 3mm from the mating surface.
PUM 488 June 2023
76 Z900A4, 77 Z650B1, 77 KZ650B1, 77 Z1000A1, 82 Z1000J2, ZRX1100R.
76 Z900A4, 77 Z650B1, 77 KZ650B1, 77 Z1000A1, 82 Z1000J2, ZRX1100R.
Re: Cannot get float heights correct
warren3200gt wrote:I always set mine 3mm from the mating surface.
+1 for that.
http://www.airevalleyclassics.co.uk
10% discount code Z1OCTEN
Keyster rebuild kits & carburettor spares - airscrews, jets, needles, starter plungers & gaskets.
Also petrol/ethanol proof float bowl gaskets. IMD pistons preferred seller.
10% discount code Z1OCTEN
Keyster rebuild kits & carburettor spares - airscrews, jets, needles, starter plungers & gaskets.
Also petrol/ethanol proof float bowl gaskets. IMD pistons preferred seller.
Re: Cannot get float heights correct
I'm happy to say I finally got the float heights sorted
The main problem was that what I was trying was not possible.
The Clymer manual showed 3mm down from the bottom of the carb body.
The bowls go up into a recess in the carb body so this means it would actually be about 5mm from the top of the bowl.
Warren3200GT and Ultim8pc said it was from the mating surface.
This must be right and I managed to get all 3 carbs consistently 3mm from the bottom of the bowl gasket.
I also noticed worn recesses in the tangs from years of wear by the float pins. I had also made a few marks using pliers doh. These must have been making the sprung loaded pins on the float valves catch so I polished the tangs dead smooth.
Also, it might not have made a difference but I doubled up on the silver float valve washers/gaskets.
After this I got all 4 carbs consistently the same … Whoop
A friend also suggested that maybe having a bike running with vibrations also makes a difference.
I did an experiment to simulate engine vibrations but it made no difference at all.
There are some pics below showing the fuel height I achieved, the carbs on a jig then the carbs back on the bike
Thanks very much for all comments and suggestions on this post






The main problem was that what I was trying was not possible.
The Clymer manual showed 3mm down from the bottom of the carb body.
The bowls go up into a recess in the carb body so this means it would actually be about 5mm from the top of the bowl.
Warren3200GT and Ultim8pc said it was from the mating surface.
This must be right and I managed to get all 3 carbs consistently 3mm from the bottom of the bowl gasket.
I also noticed worn recesses in the tangs from years of wear by the float pins. I had also made a few marks using pliers doh. These must have been making the sprung loaded pins on the float valves catch so I polished the tangs dead smooth.
Also, it might not have made a difference but I doubled up on the silver float valve washers/gaskets.
After this I got all 4 carbs consistently the same … Whoop
A friend also suggested that maybe having a bike running with vibrations also makes a difference.
I did an experiment to simulate engine vibrations but it made no difference at all.
There are some pics below showing the fuel height I achieved, the carbs on a jig then the carbs back on the bike
Thanks very much for all comments and suggestions on this post






Last edited by JimBoUK on Sun Jun 02, 2019 6:47 pm, edited 5 times in total.
Re: Cannot get float heights correct
JimBo
Glad you got sorted!
Glad you got sorted!
http://www.airevalleyclassics.co.uk
10% discount code Z1OCTEN
Keyster rebuild kits & carburettor spares - airscrews, jets, needles, starter plungers & gaskets.
Also petrol/ethanol proof float bowl gaskets. IMD pistons preferred seller.
10% discount code Z1OCTEN
Keyster rebuild kits & carburettor spares - airscrews, jets, needles, starter plungers & gaskets.
Also petrol/ethanol proof float bowl gaskets. IMD pistons preferred seller.
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