Fuel Float Weight.

[Semper Gumby]

Does anybody have a weight in grams for the stock fuel float?  I need a number so I can see if I need to replace them or not.   :-/

[Crossrodes]

I just ordered and received a set of floats from Bing.  These are supposed to be the ethanol resistant floats.  They are a black colored float and appear to be a hollow plastic unit.  There is no number stamped on them...just the Bing name.  They are for my '79 R65 which has the flat top Bing Carb.  Each float assembly weighs 7 grams on my digital scale.

I hope this helps.

[Semper Gumby]

Cool thanks!!  I wonder if the weight is the same as the older "white" floats?

What was the part number on the Black floats from Bing?

[Bob_Roller]

The Bing part number is : 35-310, and cost is around $37 each .

[bruce_launceston]

Hi Bill

In this article it says that new floats (I assume old sytle white ones) weigh about 13 grams and old (sinking) floats may weigh 18 grams.
http://bmwmotorcycletech.info/bingcv.htm

Cheers Bruce

[quixotic]

I see that Snowbum states that about 1/3 of the floats should be above the level of the gasoline when put in a jar of the stuff.  Not even a tiny bit of my float does, but I just wanted to make sure that I'm comparing apples to apples.  I have the white solid floats attached to what looks like a stainless steel yoke.  Can I assume that this type of float should float as per Snowbum's recommendation?

Thanks in advance.

Am I also right in assuming that even if the steel yoke is touching the bottom of the container, that the rest of float should be poking its head up above the level of the gasoline?

[georgesgiralt]

hello !
IRC the floats, new; are at 12.5 gr.
I weighted a set of old floats I had in my shop against a brand new one.
If you need the exact weight, chime in I'll check tonight at home.

[Barry]

I see that Snowbum states that about 1/3 of the floats should be above the level of the gasoline when put in a jar of the stuff.Not even a tiny bit of my float does, but I just wanted to make sure that I'm comparing apples to apples.I have the white solid floats attached to what looks like a stainless steel yoke.Can I assume that this type of float should float as per Snowbum's recommendation?
 

When I checked mine some years back I recall they floated much the same as yours.  I didn't weigh them so it might have been that they were already too heavy. I'm still using the same floats without problems though. The correlation I made at the time was that when set level in the usual way I was getting no more than 24mm depth of fuel in the float bowl which convinced me that they were OK.

Any data that comes out of this thread on weight vs how they float would be of great value and should be added to the FAQ section.

[Kookaburra]

I have just received a new float ( the standard BMW white one) and it weighed in at 12 grams the one on the bike it was replacing weighed in at 13 grams.)

[Tony Smith]

Does anybody have a weight in grams for the stock fuel float?  I need a number so I can see if I need to replace them or not.   :-/

No you don't.
The weight of the individual floats will vary quite markedly, the actual float part is not a precision device. What you need to do is form a view as to whether or not the floats actually "float" properly.
 
Pour yourself a nice glass of gasoline and chuck your floats in. There should be between 1/3 and 1/2 (by volume) exposed above the gasoline. anything less than 1/3 and you need new floats, up to a third and they still float well enough to correctly maintain (after adjustment) the height of fuel in the float bowl.
 
If you have a choice, given the prevalence of Alcohol intermixed with Petrol these days by the manufacturers, I would avoid brass floats as for some reason alcohol seems to attack them and they leak quickly.
 
The only thing that can be said about brass floats is that at least they are repairable by leaving them in a warm oven long enough to drive out the gasolene, allow to cool and then resolder using acid free "electronics" solder and a nice big iron.

[quixotic]

There should be between 1/3 and 1/2 (by volume) exposed above the gasoline

I barely got a 1/3 above surface level on brand new white floats floating in premium with 0% ethanol.  The steel connector tended to weigh them down significantly.  

[Tony Smith]

I barely got a 1/3 above surface level on brand new white floats floating in premium with 0% ethanol.  The steel connector tended to weigh them down significantly.  

My point exactly, anything less than roughly 1/3 "above the line" and you don't have enough to maintain reliable float bowl level. 1/3 or more and you are off to the races.

[Luca]

If float weight is inconsistent (but how much of a difference are we talking about?) then I'd consider where the weight is to be more important than how much it is, or how high the floats sit in a glass of gasoline.

Because the floats pivot about the pin, any weight towards the outboard end will have a greater torque advantage on the float then weight on the inboard end... so if there really are noticeable variations in the floats, it would be more detrimental to have a heavy plastic float than a heavy steel connector.

What matters to the carburetor is the bowl level.  Barry's "unreliable"  and barely floating floats haven't given him a wet foot, and his bowl level was good.  That makes him and his jets happy.