TOPIC:

I'm rebuilding the carbs on my '78 Z1-R and getting close to re-fitting them to the bike (after I repair the
buggered thread on one carb body - where the needle jet screws in)

Can anyone please confirm the best way to check the float height?
I 've read that there is a preliminary "dry" method which uses a measurement taken from the carb body
to the top of the float (with inverted carb) - have heard several takes on this with varying measurements.
.
I understand that the most accurate method is the clear tube test with the carb in its normal operating orientation,
can someone please describe this method too - with measurements?

Need a definitive answer for both these methods, with diagram & pics please - for reference. for all.
Ta, Bill.

See -

The procedure is clearly described in tha factory service manual.
If that is too challenging, try typing "clear tube method" into the search box on this site and see how many threads are pulled up. It has been discussed at length several times.

Or wait until 650Ed comes to rhe rescue again.

Thanks guys - didn't mean to seem lazy
(Will make up a fuel level gauge using an old drain screw and some tube. )

According to my data, a 78 Z1R setting is 4mm for the clear tube test and 26mm for the float height.

Hey weales - forget about that carb body measurement method - it is crap- maybe if everything is brand new it might work ok.Clear tube is the best.
You just need to firmly touch the adjustment tang on the float also and get the direction right.. Take it real easy with that bit or you will be doing it for a week So as your carbs sit off the bike ,upside down on bench to work on,as float sits upside down in bowl , a slight push on tang towards top of carb will lower the level - easier to do the floats off though so you can check out other parts. Careful pushing the pins through mate..Actually carefull all round playing with those small parts especially the tangs .

G'day Zephyrrider - I had one of those too - great bike!
Mine was a '91 750 model and I had it for 12 years or so -
only problem I had was that the fuel tank would get an airlock sometimes
and engine would just gradually starve of fuel and die. Tried blowing out the breather tube and
the tank cap labyrinth seal but the problem persisted. Just had to stop,
open the tank cap then reclose it and all would be good for several hundred km.
Thanks for the tips - will take note of them!
Was sorry to see the bike go but had to sell it to fund current Z1-R project.

There is no method better than this one here. No fuel level/float height measurement is as accurate as when you can visually see where the fuel level is. Simply put..."Gravity doesn't lie".

650ed wrote: See -

Attachment ClearTubeDiagram-6.jpg not found

There should be a float height measurement somewhere. I know Suzuki, which uses VM carbs on most of their early GS family bikes, has the height listed in the service manual. Tweaking the floats to register the correct height will make the trial and error process of fine tuning the fuel level easier.

With the carbs upside down, if the weight of the float cause the spring loaded tip of the float needle to compress you should consider changing the needles. They will still work but the fuel level will be higher and less reliable than if the spring tips are stronger.

weales - airbox on your Z1R mate ? Hopefully your floats are not too far out of spec.

Yeah, who knows what setup was used before it was pulled down? The engine was o'hauled before I bought it (1st oversize and top end rebuild with no changes) so I'll be going with pretty standard carb setup for airbox & silencer, with 4:1 exhaust. The Delkevic exhaust OEM state that standard carb settings can be maintained if the baffles are not played with. I''ll be doing some careful monitoring of plug colour and performance when it's back on the road.