H1 E Carb float heights

[Wolfie]

Float height or fuel level?

Float height is easy, invert the carb and measure from the gasket face (without gasket) to the top (bottom) of the float, set to around 25mm.

Fuel level is the one requiring the previously mentioned carb bowl and plastic tube and requires much more faffing around.

In most cases setting the float height is sufficient for good running.

[BIG H]

Put some long screws on carb body,then put in a bowl or jug,connect fuel.
fuel should stop flowing with a gap between top of fuel & under side of carb of 2 to 4mm.
DO NOT SMOKE OR HAVE NAKED FLAMES WHEN USING THIS METHOD.

[bbb]

Just sit the carb, sans float bowl, on a suitable sized glass, whiskey tumblers are about right, then as above, well easy to see fuel leve. But as Wolfie says, float height setting is usually good enough!

[147Madmax]

I'm scratching my head.
The Carbs were weeping if the fuel cock was turned to prime, when the cock was turned to on or Reserve and after a run there was also signs of weeping. I ordered 3 carb kits, only using the float valve and float needle along with the float bowl gaskets.
I have set the float heights in stages ranging from 22mm to 28mm but the gasket still weeps.
Unable to pysically see the fuel level once the bowl is attached I assumed that the floats themselves were perhaps weak and perhaps not as buoyant as when new.
I order 3 new floats from "NRP" however same problem.
Ive tried the method suggested using a glass vessels as in the photos with the long screws holding the carb off of the bottom of the
vessel, great I can see the level and all is good, the level stays where I want it and holds firm for hours.
However when i connect the float bowl and connect fuel, back to square one the fuel weeps from float bowl gasket area.
I can't see that the floats are catching in the bowl.
Has anyone else suffered similar or indeed know what I'm missing.

[mraxl]

Be sure to check the brass tube in the float bowl. They can become cracked or loose and cause the problem.

[Wolfie]

As you can see from the top picture, the fuel level never actually reaches the gasket, which is correct, it shouldn't

There have been a few cases where the metal of the bowl has become porous, But you'd have to be very unlucky to find all three porous..

So.. is the fuel pipe a good tight fit on the brass tube? and are there some pipe clips on the pipe also? Leaking from there would give the impression of a leaking gasket.

[147Madmax]

Thank you for your help.
Yes fuel pipes are a tight fit with hose clamps fitted.
I understand your logic that it may drip down and appear to be leaking elsewhere, unfortunately this isn’t the case in this instance.

[147Madmax]

Hi Mraxi.
I ruled out a fracture or loose brass overflow pipe in the float bowl as surly that would result in a leakage from underneath the float bowl, mine are leaking where the body to bowl join area.
Forgot to mention that the overflow pipes are clear of blockages.

[Kawaclive]

You mentioned that the fuel tap was letting fuel through when not in the prime position, this shows your fuel tap needs repairing.
The easiest and most foolproof way is to exchange your tap for one of Tango’s modified ones that have an OFF position.
Also was your bike leaking when on the side stand as it was probably leaning too far so the fuel can seep through the paper gaskets. Tango also sells rubber float bowl gaskets.
Also if you are using fuel with ethanol in and float valves with rubber tips they can swell up and leak.
Tango’s details are in the Members Section.
If you find your bike is leaning too far causing the problem you can either repair the pivot point if it has too much play, extend the stand or just carry a small foot of wood or plastic in the tail piece to pit under the side stand to stop it leaning so far.

[147Madmax]

Hi Kawaclive.
Thanks for your advice.
The fuel cock was working correctly, it maybe that I wasn’t quite clear in my wording.
I can’t confirm if it leaked when on the side stand, as I am aware that by doing so can heighten the chance of the carbs leaking.
I always use ESSO premium so as to reduce the risk of ethanol issues.
The float valves are not the rubber tip type.
I didn’t know that anyone did rubber float bowl gaskets, I’m thinking it’s worth trying the rubber type float bowl gaskets that tango sells ?
I will try and find him on the site.

[mraxl]

Float should be set at 24mm.
When on centerstand the fuel level never should get to the gasket.
I wasn't able to follow your pics but it should be noted that new needle/seats don't always seal.
There was a guy that refused to acknowledge that fact and after pulling out his hair a new set fixed his problem.

[Triple Parts]

Also if you are using fuel with ethanol in and float valves with rubber tips they can swell up and leak.

Never had a problem with Viton tipped float needles, Viton is used because of its high resistance to biofuels.

[147Madmax]

Also if you are using fuel with ethanol in and float valves with rubber tips they can swell up and leak.

Never had a problem with Viton tipped float needles, Viton is used because of its high resistance to biofuels.

It’s worth trying. Do you have a link to the Viton tipped float needles please ?

[thelodgers]

Are you certain the floats are not catching the mounting posts or the sides of the float bowl as they rise ? I seem to remember Dave Higgs mentioning this in his excellent carb balancing article. The floats shouldn't be parallel to the side of the bowls but slightly twisted to rise properly without touching anything.

[147Madmax]

Are you certain the floats are not catching the mounting posts or the sides of the float bowl as they rise ? I seem to remember Dave Higgs mentioning this in his excellent carb balancing article. The floats shouldn't be parallel to the side of the bowls but slightly twisted to rise properly without touching anything.

If I’m honest, no I’m not certain, the only thing I’m certain about is loosing the will to live with these things.
It has dawned on me that the floats may be catching at the top of their travel. Ideally if I had a spare float bowl I could modify it and use a clear pipe to actually see the fuel level inside. Sadly I haven’t, I have checked out eBay with only the odd one showing in the states.

[Triple Parts]

It’s worth trying. Do you have a link to the Viton tipped float needles please ?

You could try Steve at Motocarb but I got mine from New Zealand
http://www.smebike.com/carburetor,%20pa ... bly-viton-

[Nigel S]

I have to agree with the thoughts above.
When on test top picture the fuel level is below gasket face.
But when bowl is on fuel seeps out the gasket face.

Therefore there must be interference between bowl and float

[mraxl]

Another item to check for is a warped float bowl gasket surface.

[147Madmax]

I have to agree with the thoughts above.
When on test top picture the fuel level is below gasket face.
But when bowl is on fuel seeps out the gasket face.

Therefore there must be interference between bowl and float

Hi Nigel S
Thank you for your input.
It seems strange that all 3 carbs would suffer the same problem though

[147Madmax]

Another item to check for is a warped float bowl gasket surface.

Hi mraxi

Yes I’m trying some different style of gaskets which may over come the issue.
Tangoman is sending me some, so I will keep you all posted.

[mraxl]

It's pretty easy to check for warped float bowls.... just put a metal ruler or other straight edge on the surfaces and see if there is any light between.
If there is an uneven surface just put a piece of sandpaper on a flat surface and run the bowl across it until it evens out.

[147Madmax]

It's pretty easy to check for warped float bowls.... just put a metal ruler or other straight edge on the surfaces and see if there is any light between.
If there is an uneven surface just put a piece of sandpaper on a flat surface and run the bowl across it until it evens out.

Thank you maxi.
Yes bowls are warped