Cannot get float heights correct

[JimBoUK]

Hi,

I have a Z1000A1 that for a while has been leaking petrol from the carbs where the fuel level is going over the top of the bowls.
The carbs have just had a full rebuild cleaning everything in an ultrasonic cleaner.
Before putting them back on the bike I am trying to set the fuel heights with the bank of carbs monuted on a wooden jig and using the clear tube method.
After spending many hours fiddling I cannot get it right.
I have tried searching the forum but cannot find anything to help.

I am trying to set the height 1/8" or 3.2mm below the flange at the bottom of the carb body.
Whilst doing this the float bowl gaskets are fitted.
Is this the correct approach ?

To start with I am making sure the main brass piece connected to the plastic floats is as straight as possible with the tang level to the main brass piece.
At this point the fuel level is too high, reaching or going over the bottom of the carb body.
When I adjust the tang it makes little difference.
It gets to a point where the angle of the tang bend is too much so I have also tried bending the floats down a bit but when doing this the float bottoms are lifted by the bowl when it is screwed on and can then easily close the valve letting no fuel in at all.
The results I am seeing are also inconsistent. One minute I seem to get the level right then I try again and it is too high.
I've tried so much I have lost track but maybe when this happened the tang angles were too great.

I also posted on the Kzrider forum whilst waiting for an issue to be fixed with my logon to the Z1 owners site.
One suggestion there is it could be down to non original float valves.
The valves I have fitted and came from ZPower about 10 years ago. The bike has not been used much and the float valves are in good condition with no signs of wear.
I cannot remember for sure if they are original parts but I suspect not. At ZPower genuine float valves are over £30 where non genuine are £10 each so I suspect I went with the cheaper option. Somoeone also said the genuine ones have 2.0 stamped on them and mine do not.

Sorry about the big essay describing the problem but I wanted to get it all across.
I'm out of ideas, have lost many hours and am loosing my sanity
Please help

Thanks in advance

Jim

[warren3200gt]

Hi Jim, glad you found your way here. Genuine float valves are about 30 quid if you get them from zpower, allens performance or where ever so if if you think you paid less then chances are yours are not genuine and therein lies your problem I suspect.
Bite the bullit and get some genuine ones it'll save you loads of frustration and get you on the road.

[DavidZ1R]

I must admit, I had similar issues when I tried to set the float heights, in the end I replaced the new valves with the old original ones, I found the new ones were smaller and made setting the height impossible, when I did get the right height the needle valve would drop out.

[Al]

I have bought supposedly good float needles from a reputable company and found eventually that they were too short which meant the tang on the float was hitting the outer rim of the brass seat before the valves would close.
AL

[z1bman]

only fit genuine the pattern ones almost impossible to get rite

[Garry.L]

A1 is a Gravity fuel tap and they are VERY prone to passing, more so if they've been allowed to dry out at any point. Only real cure is a new tap as seal kits wont repair this fault.

[needaz1100r]

A1 is a Gravity fuel tap and they are VERY prone to passing, more so if they've been allowed to dry out at any point. Only real cure is a new tap as seal kits wont repair this fault.

The tap should not cause or allow the carbs to overflow, whether passing whilst off or left on.

[Pauldonjuan]

I've just been setting the float levels on my a4, guess they are the same.
Mine have the original floats still installed. The problem was the same, levels so high they were dribbling out of the overflow.
I started by checking the float height by measuring the float height with the carbs up side down, they were all the same at 26 mm, I increased this to 28 mm then mounted the carbs on a jig to check the actual level. They all turned out to be on the maximum tolerance at 1 mm below the carb body.
Obviously something has worn over the bikes 43 year life or is it the actual floats that are less buoyant that they were when new?

[warren3200gt]

Two things generally wear on the needles. The internal spring weakens and the needle seat wears. Both reduce the working length of the needle and hence increases the fuel level if left un adjusted.

[JimBoUK]

Thanks for all the reply's.

So it sounds like the most probable cause of the issue is the fact I have non-genuine float valves.

PaulDonJuan. I guess that's a possible good theory about the floats loosing buoyancy with age.
Maybe the fact the fuel properties have also changed since the bikes were designed over 40 years ago also comes into play.
How did you get around this ?
New floats from ZPower are £75 each

I think my plan is to buy 1 genuine float valve (Don't want to spend £120 on 4 if I don't have to)
If the new float valve makes setting up a carb easy I'll get 3 more.
I will also ask the guys at ZPower for their thoughts when I order it

[Garry.L]

A1 is a Gravity fuel tap and they are VERY prone to passing, more so if they've been allowed to dry out at any point. Only real cure is a new tap as seal kits wont repair this fault.

The tap should not cause or allow the carbs to overflow, whether passing whilst off or left on.

Of course, but on old or pattern float valves and worn seats combined with the pressure of a full tank of fuel through a Tap that's not shutting off correctly and 3 days after you've parked your bike it' suddenly becomes incontinent.

[Ultim8pc]

There are some rubbish carb parts out there. Using genuine is best, but most folks can't run to the cost. I use Keyster in my rebuilds, I have found them to work well.
Setting the float heights can be a bit of a chore and requires patience.
replacing the float valves and seat should't change the float height much and thus shouldn't need much adjustment.

[Pauldonjuan]

Just a thought and maybe a daft one, you say your floats are fouling the bottom of the float chamber, is it possible the floats were installed up side down? I don't know if this is possible but just a thought...

[JimBoUK]

The floats only foul the bottom of the float chamber if I bend them down a bit to try and compensate and keep the tang as level as possible.
They are definitely the right way up.

[HighlandStu]

Did you get it sorted in the end ? I did my A1 float heights recently, took a few attempts but was okay - hard to get it perfect on an old bike.
I'm no expert but I'm just down the road in Old Warden - I'll take a quick look if you want ?