Andover Fuel level tool 13.1688

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Anybody know what the tilt angle is for stock carbs on a Commando?
With my bike sitting on its tires on a level concrete floor the difference between 0º (or verticle level) to the carb bowl upward pitch/angle measurement shows 9.80º .
I would wager that no two Nortons would give you the exact same angle of reference but 9.8º to 10º should be an accurate reference for the calculations you seek.
 
They said that about the Titanic :oops:
You took the words right out of my mouth. Marvel Schebler said the same thing about their foam floats. [ie They are "sink proof"] They have since been removed, due to aircraft falling out of the sky! The truth will out, in due time. I'll stick with the plastic floats.

PS I may be wrong. Time will tell. Call me a skeptic, I've seen these same claims made by other manufacturers. In the mean time, I'll stick with plastic. I've owned dozens of British motorcycles with Amal Concentric carbs. I've never had a bad float. Of course, I treat them with care and respect.
 
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Yep, the introduction of foam floats was about saving money, not about making a better float. They are punched out of a piece of foam; plastic or brass floats are FAR more difficult/expensive to produce. I ASSUME (a dangerous assumption) that a current foam float is superior to the older versions but I don't know that to be the case. Quadrajet foam floats were well known to absorb fuel over a couple of years though they could make it through the warranty period, which is the ONLY thing that matters in most mass-production applications.

I can't claim to have a lot of experience with a multitude of AMAL floats but I never had a plastic one fail and the originals in my 1973 carbs (replaced by premiers in '18) are in perfect operating condition. I do have a lot of experience with foam floats on auto carbs and none of it is favorable.
 
Interesting discussion. I've been pondering getting the stay up floats, for the simple fact of the ability
to adjust them. I messed around with raising my fuel levels this year, but as mentioned by others
very tricky with a drift. The trade off for the integrity of the material will have to be worth it, as having
a well idling machine is imperative. Reckon if I find myself that concerned about float rot, the carbs can
be removed for inspection every other season. The only time I had any issues with bad floats
on anything had to do with a non-functioning fuel gauge in my old Ford Bronco. Dropping the gas tank revealed a brass
float on the sending unit full of holes.
 
I agree that the OEM adjustment method was a PITA compared to bending a tab. OTOH, it's not like you had to do it periodically. Although I adjusted the float level initially on several Amals, I never had to reset them at a subsequent carb overhaul. The floats on my OEM (sleeved) Amals on my '73 never required re-adjustment after checking/setting them in '06 when I bought the bike. They were on the machine until '18 when I purchased a set of Premiers. They didn't need replacing, I was just in a 'mood' that I wanted new carbs!

Kind of like purchasing a new record turntable when the old one works perfectly! Upgrading old, obsolete technology with new obsolete technology is an interesting concept. But it's pretty much what we do with Nortons as well! ;)
 
Those stay up floats do look very easy to adjust
I've never looked at them but I assume you bend the tang like you would on a mikuni or similar?
But it's really not that hard to drift the float needle seat up or down to set it up correctly,
The correct parallel pin punch and a toffee hammer will do it easily
Set and forget
 
The correct parallel pin punch and a toffee hammer will do it easily
After you soak it in boiling water or heat it with a torch, and you'd better have calipers handy to measure how much it moved....
I've done it, but it ain't fun.
 
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After you soak it in boiling water or heat it with a torch, and you'd better have calipers handy to measure how much it moved....
I've done it, but it ain't fun.
I use a hot air gun ,heat is your friend here
 
Yep, the introduction of foam floats was about saving money, not about making a better float. They are punched out of a piece of foam; plastic or brass floats are FAR more difficult/expensive to produce. I ASSUME (a dangerous assumption) that a current foam float is superior to the older versions but I don't know that to be the case. Quadrajet foam floats were well known to absorb fuel over a couple of years though they could make it through the warranty period, which is the ONLY thing that matters in most mass-production applications.

I can't claim to have a lot of experience with a multitude of AMAL floats but I never had a plastic one fail and the originals in my 1973 carbs (replaced by premiers in '18) are in perfect operating condition. I do have a lot of experience with foam floats on auto carbs and none of it is favorable.
Mike, You are correct about foam floats being cheaper to make. I'm planning on Amal Premiers for my Mk III project. However, I'm going to save my old plastic floats and matching float bowls, for when those foam floats sink. Lots of issues with foam floats on Lycoming, Continental and Rotax aircraft engines. Linked below is a thread about sinking Rotax floats. It's 24 pages long! :eek:

Joining the "Sinker" club

Does anyone know what the weight is of the new foam floats?
 
Mike, You are correct about foam floats being cheaper to make. I'm planning on Amal Premiers for my Mk III project. However, I'm going to save my old plastic floats and matching float bowls, for when those foam floats sink. Lots of issues with foam floats on Lycoming, Continental and Rotax aircraft engines. Linked below is a thread about sinking Rotax floats. It's 24 pages long! :eek:

Joining the "Sinker" club

Does anyone know what the weight is of the new foam floats?

I'm not sure Amal StayUp floats are "punched from a piece of foam" (but moulded as they have what appears to be a joint line?).
Andover Fuel level tool 13.1688


Considering the "new" Amal StayUp floats have been around for 11 years now, how many failures reported in that time?
 
I don't see why there is all this fussing about bowl angles to get some perfect fuel level set. If it was so critical, we'd be having a terrible time starting, idling etc whenever at a non ideal angle to ground, be it left/right lean, seating position, weight, up/down hill riding etc.
Fuel pickup is at near bottom of bowl. Difference in hydrostatic pressure at various bowl angles will be extremely small.
I say relax, get 'er in ballpark, and go riding.
 
Mike, You are correct about foam floats being cheaper to make. I'm planning on Amal Premiers for my Mk III project. However, I'm going to save my old plastic floats and matching float bowls, for when those foam floats sink. Lots of issues with foam floats on Lycoming, Continental and Rotax aircraft engines. Linked below is a thread about sinking Rotax floats. It's 24 pages long! :eek:

Joining the "Sinker" club

Does anyone know what the weight is of the new foam floats?
Yea, bugger all when immersed in petrol, surprise surprise they float!
 
"
Don't be surprised when Amal switches away from foam floats in a decade.
A sinking float on a Norton is nowhere as thrilling as on a Cessna."

I'll bet that's TRUE!!! :)
I doubt they have floats on Cessna. What happens when the plane flies upside down. They do you know. They have very large and very special chainsaw carbs [ as an example ]. They work at any angle. They use a diaphragm instead of a float. Any dumb shit ought to know that. Come on. Please don't make uneducated guesses or presumptions. It spoils the forum for those who are not that mechanically minded.
 
I read in the Andover Norton 'The Source there were (square edge) floats in some Premiers that might cause some form of running problem.
Something to check perhaps.
 
I doubt they have floats on Cessna. What happens when the plane flies upside down. They do you know. They have very large and very special chainsaw carbs [ as an example ]. They work at any angle. They use a diaphragm instead of a float. Any dumb shit ought to know that. Come on. Please don't make uneducated guesses or presumptions. It spoils the forum for those who are not that mechanically minded.
Thanks for the insult. I'm not the one who doesn't know what he's talking about. FYI, most piston aircraft engines which are not fuel injected [including Cessnas] use a single barrel, updraft carburetor WITH a float.

Foam Float Replacement Service Bulletin

For your information, most Cessnas are in the Utility category, which means they are not allowed to do aerobatics. Aircraft have to be in the Aerobatic category to do loops, rolls, etc. The Cessna 150 Aerobat is in the aerobatic category. It is a basic aerobatic trainer. It has a float type carburetor, like the ones mentioned in the service bulletin linked above. Positive G maneuvers, like loops and rolls, CAN be performed with a float type carburetor. You only need a pressure carburetor or fuel injection to perform negative G maneuvers, like inverted flight. You also need an inverted oil system.
 
My apologies. I would not have thought a modern aircraft would have floats in it carbs. My mistake.

Dereck
 
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