Topic: Measuring float height

[mtr]

I know this question has been asked before, but I can't find it.

When measuring float height, do you measure from the bottom of the float to the level where the bowl connects to the carb body? This was my assumption but I'm a complete carbtard. Seeing as how setting all the floats to 22mm on my 550F left me with fuel pouring out of the overflow hoses, I think I may be doing it wrong.

Also, another stupid question: with the carbs installed on the bike are the float needles inserted with the point or the spring facing downward?

The carb model is 069A if that matters at all.

Thanks.

[Laminar]

Measure from the area of the carb body that the bowl gasket contacts to the lowest point of the float when the float is just touching the float valve spring. The float valve should have the pointed end inside of the float valve body, and the spring sticking out, touching the float's tang (touching tang? Sounds dirty).

[Laminar]

[mtr]

when the float is just touching the float valve spring

The spring on the end of the float needle, right? Am I using the wrong terminology here? Again, I'm a self-confessed idiot.

If we are talking about the same spring, is there a point when the float tang shouldn't be in contact with the spring? My float valves (or needles) are always touching the tangs. They're just hanging loose inside the carb body, gravity pushes them in contact with the tang. This is with the carbs installed, I'm trying to avoid taking them out twice in one day if at all possible.

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I wish that picture was more clear. Did that come from one of the shop manuals? I might be able to look it up.

So, the carbs in the picture seem to be on their side. It is possible to measure float height with the carbs installed, right?

[Laminar]

when the float is just touching the float valve spring

The spring on the end of the float needle, right? Am I using the wrong terminology here? Again, I'm a self-confessed idiot.

You're correct (on the first point, I'll hold my thoughts on the last  )

If we are talking about the same spring, is there a point when the float tang shouldn't be in contact with the spring? My float valves (or needles) are always touching the tangs. They're just hanging loose inside the carb body, gravity pushes them in contact with the tang. This is with the carbs installed, I'm trying to avoid taking them out twice in one day if at all possible.

This is correct. You measure the float height at the point where the float has pushed the float valve into the float valve body and has just started to compress that spring

I wish that picture was more clear. Did that come from one of the shop manuals? I might be able to look it up.

It is, but I found it posted on these forums.

So, the carbs in the picture seem to be on their side. It is possible to measure float height with the carbs installed, right?

It's possible, but it would be very cumbersome, especially trying to get to the middle two floats, since you have to be able to see the float valve to know when the float tang is compressing the spring.

[Laminar]

Here's a tool someone in another thread recommended making out of plexiglass or metal:


The U-shape goes around the float and touches the carb body. The bottom of the U pushes against the float. Put it on the carb, adjust float tang, re-check, etc. You could also make the U deeper and thread a screw vertically through the bottom of the U so that you can adjust your desired height.

[NickC]

I made mine out of cardboard 

[kedwards]

Hi guys I used to own an italian 1975 500/4 k3 and i set the levels , by removing carbs off of the bike and tuning them upside down , then using the measurement in the haynes manual i set the float heights by bending the tangs , i set the pilot adjuster screws to the manual specs , put it all back on the bike started it up put the vaccum testers on adjusted the vacs , and for the three years i owned the bike it never missed a beat , a fantastic little bike that one.

[Johnny5]

I made mine out of cardboard 

Yep, I made mine out of an expired Chili's Restaurant gift card. 

[Johnie]

I made mine out of cardboard 

Yep, I made mine out of an expired Chili's Restaurant gift card. 

Here is mine from a floopy...