Amal StayUp Float Adjustment Confusion

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I just got a set of StayUp floats, and the instructions, while providing a bit of history, are quite vague regarding the actual setup. My bike is an 1973 850
Interstate. I gather from the instructions that I should set up the floats so that the float tops are parallel, and a little above, the top of the float chamber
when the float valve is closed, but those would be for Carbs produced after May 1986, and my carbs are original carbs for my 1973. Should I be using the 1986 adjustment, or the 1972 adjustment with the float top 0.80 inches from the float chamber top? Should I be adjusting the floats dry until the valve seats, or should I be dribbling fuel into the open float bowl until the valve seats for a more accurate setting? I would like to do this the right way.
Thanks
 
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The instructions say that 1966-1972 carbs the float sits 0.80 " below top of float bowl....that must be a typo as that is more that 3/4 of an inch...they must have meant 0.08" Doing a search now from "float " postings of the past to get some direction....I think I will email Amal directly
 
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There are several different recommended settings for Amals (with original floats, depending on when the recommendation was written. I have found that the .080 below the top of the bowl works well and have seen no reason to try anything else. The stay up floats should have some sort of instructions re that because it is possible that they "float" quite differently in the bowl relative to the needle position than do the original Amal floats.
 
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I got a pair and set them above and parallel to the tops of the bowl rim. Hooked the fuel lines up to both and added water with a turkey baster until the floats closed the needles on the seats and stopped the flow. One was perfect from the get-go and the other had to be reset. Took two more tries to get the off one set up exactly as the correct one. 932s on a '75 MkIII motor.
 
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Keep in mind that they will float higher on water than they will on gasoline so the level of fuel in the bowl will be higher at the same float setting with gas than it was with water. I'd suggest you just set them dry as per the Amal guides, using whatever particular float setting of the various recommendations you like.
 

L.A.B.

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singring said:
The instructions say that 1966-1972 carbs the float sits 0.80 " below top of float bowl....that must be a typo

Where does it say that? The Amal instructions say 0.080", not 0.80"

"...adjust the tangs of the Stayup float so that the far edge of the float sits 0.080” below the top of the float bowl."
http://www.amalcarb.co.uk/TechnicalDetail.aspx?id=13




singring said:
Should I be using the 1986 adjustment, or the 1972 adjustment with the float top 0.80 inches from the float chamber top? Should I be adjusting the floats dry until the valve seats, or should I be dribbling fuel into the open float bowl until the valve seats for a more accurate setting? I would like to do this the right way.


Forget about setting the float heights to a specific measurement.

What you should be doing is setting the fuel level
The correct fuel level for all Mark 1 Concentric carburetters is 0.21” plus or minus 0.040” below the top edge of the float bowl. Thus when the needle valve is being held shut by the tangs of the float, the level of the fuel will be between 0.17” to 0.25” (4.33mm to 6.35mm) from the top of the bowl.
 
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L.A.B., I hear you....I intend to adjust the floats according to the fuel level in the bowls. I emailed Amal, and hopefully will get a reply soon for confirmation.
As far as the instruction sheet I got with the StayUp floats it says " ...adjust the tangs of the StayUp float so that the far edge of the float sits 0.80" below the top of the float bowl. " this was for carbs 1966-1972....I kid you, not.... 0.80" .....definately a typo, and a bad one for anyone who is completely new to Amals.
I also informed Amal in my email of the error in their instruction sheet.
 
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