float height

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Silverback56

float height

Post by Silverback56 »

Hi can anyone tell me the float height settings for A model carbs Ive read in Haynes manual it should be 27.6 from upper flange of carb to top of float but the diagram refers to j k models then read that people measure from top of gasket and others from gasket face on carb .
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BATTS
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Re: float height

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Chris
76 GT750, 78 GT550, BMW K1600gtl
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astrax
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Re: float height

Post by astrax »

Silverback56 wrote:Hi can anyone tell me the float height settings for A model carbs Ive read in Haynes manual it should be 27.6 from upper flange of carb to top of float but the diagram refers to j k models then read that people measure from top of gasket and others from gasket face on carb .
Hi
The standard height of the floats should be 27.6mm from the carb face ( gasket removed )
Below is a tool I made for checking
Image

Thanks
Ian
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Silverback56

Re: float height

Post by Silverback56 »

Thanks Ian
swarrans
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Re: float height

Post by swarrans »

The link says with gasket in place and Ian says without?....

Simon
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astrax
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Re: float height

Post by astrax »

I have always measured without a gasket, directly from the carb face, then it will always be the same, new gasket, old gasket, pattern gasket may vary in thickness, probably not very much though.

Setting the floats to 27.6mm with the gasket in place, would give less fuel in the float bowl than measuring 27.6mm from the carb body without the gasket.

The image below is taken from the Suzuki GT carburettor service manual, it says "without thickness of gasket"
Suzuki GT Series Caburetor Service Manual.png

Thanks
Ian
swarrans
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Re: float height

Post by swarrans »

I'm not doubting you Ian, but I bought Baz's dvd and set mine according to that and now wonder if they are right?

Simon
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Re: float height

Post by astrax »

swarrans wrote:I'm not doubting you Ian, but I bought Baz's dvd and set mine according to that and now wonder if they are right?

Simon
Hi Simon
Not having the gasket in place is how I have read it should be measured, and that's the way I have done since I got my kettle in 1983, not saying that is right
Assuming Suzuki got it right in the first place, there are times when the float heights may need to be set different than the recommended setting as this affects the fuel delivery.

Found this on a website which sums up the effect of the level quite well

The fuel level in the float chamber is therefore a calibration element of the carburettor, since the metered fuel delivery changes with float level, and therefore affects the mixture ratio.
By having a high float level, a greater fuel quantity is delivered compared to the case with a low float level, under all operating conditions and for all of the carburettor's circuits.

Remembering, a higher float level is a smaller number, like 25.0mm rather than normal 27.6mm, if that makes sense ?


Thanks
Ian
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