Amal carb fun facts

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seattle##gs

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My Norton has dual amals. While tickling them I can count to 3 on the left side and 17 on the right side before they flood over. I know the float levels are dead-on so I began to pull the roll pin micro bit by micro bit down out of its aluminum button. On try #3 the roll pin and aluminum button parted company. The spring shot out and vanished, making a simple job much longer. I have some spare carbs so I scavenged a spring . Now, I solved the mystery as to why I was making poor progress by shifting the roll pin. My roll pin is shorter than the spare! Problem solved. Perhaps this will be useful to others.
 
Mine does the same - with both float levels set correctly. I once thought about trying to correct it but since the ticklers work "correctly" when factoring in the extra time on the right side, I decided that (by old brittbike standards), it wasn't broke so I didn't fix it. ;)

I'm trying to get a friend who just bought a Mark III to dump the single Mikuni that is on the bike and put a pair of Amals back on it but his big issue is he doesn't want to fool with tickling! He feels it's too dangerous...gas dripping, etc...
 
Far too much time on your hands....IMHO
Not sure which side the main fuel tap is,,,, but I bet the slow filling carb is on the opposite side...
Likewise if you do the same using the reserve tap the characteristic will swap sides
I think its to due the fuel flow through the carb banjo's & banjo bolts
If you think its bad on a twin... try it on a triple
On AN website I see they sell a fuel line assembly that allows both bowls to fill... either main or reserve without the fuel having to go through the other

Malc
 
concours said:
MexicoMike said:
He feels it's too dangerous...gas dripping, etc...
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Suspend his man card immediately, pending a board review. Suggest a Prius for him.
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Agree completely! Dangerous? Jeepers, it's a motorcycle!

As for it taking longer because it is on the side away from the tap, you can check that pretty easily by turning on both taps. It won't change the time required in my experience.

Russ
 
I have a clock on my MK3 and count 7 secs of tickling for good starting. On another note how does everyone seal up the plastic screens to the fuel line banjos? I have used Teflon tape wound carefully around the screen flanges , although it works it is very finicky and a pain.
 
jimbo said:
I have a clock on my MK3 and count 7 secs of tickling for good starting. On another note how does everyone seal up the plastic screens to the fuel line banjos? I have used Teflon tape wound carefully around the screen flanges , although it works it is very finicky and a pain.
Click to expand...


I've never put anything on there before. The screen flange should seal the banjo to the float bowl and the copper washer seals the bolt. With gas running down at every cold start, how could you even tell if it was weeping?
 
jimbo said:
I have a clock on my MK3 and count 7 secs of tickling for good starting. On another note how does everyone seal up the plastic screens to the fuel line banjos? I have used Teflon tape wound carefully around the screen flanges , although it works it is very finicky and a pain.
Click to expand...

I think I've seen leaks there when the fibre washer under the bolt head is too thin, allowing the bolt threads to bottom out.

Teflon tape is bad stuff to have floating around in your carburettor.
 
Triton Thrasher said:
I think I've seen leaks there when the fibre washer under the bolt head is too thin, allowing the bolt threads to bottom out.

Teflon tape is bad stuff to have floating around in your carburettor.
Click to expand...
It never gets inside. "The screen flange should seal the banjo to the float bowl " but it don't sometimes , maybe new screens would be better? I also found pitting at the area where the screen butts up to the bowl and had to find another bowl.
 
Those fibre washers are thin, but they work for me. If there's a leak there and the washer's ok, I just tighten the screw a bit more and it stops. I've got the impression over the years that these washers are a bit of a secret, e.g. Andover Norton doesn't list them on the relevant page for my bike, or another one that I just checked at random for a '71 750. And they're not in the parts books that I have. My experience, though, has been that you can get them easily enough if you ask for them, across the counter, over the phone or whatever – and, lo and behold, AN do stock them, but (as far as I've seen) you need the part number. Weird, seeing as they're a genuine Amal part. It's not like they're a new thing, either, I'm quite sure I remember replacing one on a BSA in the late '70s.
 
update...I spent a couple of months balancing and adjusting a pair of amals .....new motor, new Amals, so I had everything going for me and it still took lots of hours and trial and error. Now several months have gone by and they have stayed in tune and the bike is usually a first kick starter with no problems. I have dealt with bushel baskets of amals and I am not one to speak well of them but I seem to have reached an almost mythical state where they aren't fighting each other or changing their settings. It really is smooth and predictable......day after day, month after month. It just took an awful long time to get there. Not saying I wouldn't change to a better carburetor in a second but this is some one else's bike and he refuses to put on a single Mikuni.
 
The plastic screen inside the banjo can take a set plus with age no longer seal, only cure is replacement so I keep 2 spare for my 9 concentrics.
 
seattle##gs said:
update...I spent a couple of months balancing and adjusting a pair of amals .....new motor, new Amals, so I had everything going for me and it still took lots of hours and trial and error. Now several months have gone by and they have stayed in tune and the bike is usually a first kick starter with no problems. I have dealt with bushel baskets of amals and I am not one to speak well of them but I seem to have reached an almost mythical state where they aren't fighting each other or changing their settings. It really is smooth and predictable......day after day, month after month. It just took an awful long time to get there. Not saying I wouldn't change to a better carburetor in a second but this is some one else's bike and he refuses to put on a single Mikuni.
Click to expand...
I have had very similar experience to yours, cable tie the splitter to the frame ,micro adjust carbs with a vacuum gage at tickover then adjust the balance concentrating on where the slides lift off of the idle adjusting screws as opposed to just balancing the carbs ,get the jetting dead right with an o2 sensor etc has made my Norton run better than I would have thought possible
 
kommando said:
The plastic screen inside the banjo can take a set plus with age no longer seal, only cure is replacement so I keep 2 spare for my 9 concentrics.
Click to expand...

9 Concentrics! Do you rotate them through your Commando weekly for reliability?
 
6 bikes, 3 twins and 3 singles with a carb for every cylinder adds up to 9 concentrics.
 
seattle##gs said:
My roll pin is shorter than the spare! Problem solved. Perhaps this will be useful to others.
Click to expand...

Good work seattle. That was always my assumption as to why one carb spit out sooner than the other. I usually just gave each tickler the same second count and called it good or maybe just waited until one spit, then called it good for both.
 
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