Unstable idling.

Can check if the little idle air passages is free after drilling with the guitar string?

Try the B string 0.016"

Bob Z. said:

Can check if the little idle air passages is free after drilling with the guitar string?

Try the B string 0.016"

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Yes,
I mean, i already did it.
But as i can control the air passage is free after doing it?
Ciao
Piero

dynodave said:

"Check the manifold face that mates with the cylinder head is flat and use all new gaskets and O rings"

Pierodn

Remember NO Norton Heavy Twin used gaskets on the intake manifolds only the hard fiber insulator between the head and manifold. see here:
carb-manifold-head-gaskets-t20148.html

If the manifold is not flat then some one ruined it....probably with a gasket.
Same for the carb....only an oring,,,never a gasket....

This generally why I don't care for forums that much, since there is an overwhelming Alzheimer effect so even an August 2014 thread is totally ignored or forgotten.

LAB must be a saint to type the same crap over and over and over and over and over.....
coffee break over, back to work for me.

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Maybe you should answer all the posts or provide a cross reference to all other post son the subject so that all information is correct? Or perhaps you would like to set rules to who can post and who can't?

However, self righteous you may be, but you are also right, I should have referred to 'CARB.INTAKE INSULATOR 06.2700 PN 063458

However you will note I did say O rings, so O RING 16/101,622/101,03.3281 PN 990522

Yes, if the manifold is not flat someone ruined it, how they did that is not real easy to tell without laying out the parts. as a '50s MG owner I always recall that SU installations use a gasket on each side of the insulator because the hard insulator is not that good of a seal on its own. I will not be using an insulator on my own Norton installation, because I have non standard manifolds and rubber mounted carbs.

Personally I am frustrated by owners and posters who are always looking for the solution that does not involve stripping the suspect parts for proper inspection.

Having said that, and part of the reason why I said that, is that I have wasted my own time recently trying to avoid a dissasembly.....that has only convinced me more....accept the challenge, strip the parts and check everything. Poking with a guitar string is something to do when on the road and you need to get home, not when you are in your workshop.

Good luck Piero. I understand you are getting other peoples rants in a second language, and you just want a quick fix......

However I am also sure you will learn a lot more by removing the carbs and doing a thorough job, once.

Me, I will try to take my own advice.

A worn needle jet will always make the plugs black, even if the idle mixture is lean. You spend more time running on the needle jet than you do idling. A needle jet will be worn out and bigger than 0.106" at about 10,000 miles and cause richness up to about 1/3 throttle.

Another place you can have an air leak at idle is the float bowl gasket. The idle fuel passes through that gasket, and if if the float bowl surface isn't flat you'll be sucking air into the idle fuel channel.

ludwig said:

In the initial post :
" The two Champion N7YC spark plugs are very dirty black. " ( quote)

Then SteveA suggest :
"first thing you should do is check if you have an air leak....weak mixtures will cause fast running at lower rpms.." (quote)

Where is the logic in that ?

A search for " Amal " gave 4954 results .
The subject has thoroughly beaten to death .
Maybe Pierro can do some reading up before asking questions ?

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I guess on the surface you are right on two counts......

certainly its beaten to death.....so after this I promise I am gone.....

Black plugs indicate rich running? well I accept there is logic in that, but, surely no engine is going to start easily and then idle at 2000rpm when hot if its that rich?, my assumption was that the plugs are a misleading indicator.

Of course I may be wrong, and maybe I should not assume. But plugs often are misleading indicator, since they are not self cleaaning, the have a habit of showing what happened before, rather than what is happening right now. Unless you control the situation with the use of new plugs from Hobot's V8 packs.

Maybe this is useful to Piero even if he does do the sensible thing and buy the Premiers from Jerry?

https://www.oldbritts.com/amal_tun.html

Good luck Piero.

Dear All,
thank you.
I already use the 0,0016 guitar strim.
But as i can control the air passage is free after doing it?
Ciao
Piero

Piero,

If you remove the idle jet screw, get some carb cleaner with a spray nozzle and small tube on it. Remove the float bowl and air cleaner. Spray the carb cleaner into the idle jet screw port, observe the cleaner coming out of the needle jet, and also the open hole by the air intake. If it doesn't come out of these 2 holes, the idle circuit is plugged and you need to clean it somehow. I find it very hard to find that little .016 hole with the guitar wire but it is possible. If the circuit is clear, you probably have an air leak, either the carb to manifold to head somewhere, or possibly like I said the slides are worn, they too will let plenty air around them at idle and give a very inconsistent air/fuel mix so it's impossible to get good idle.

If the carbs are old, I would look into rebuilding/re-sleeving or buy the new Premiere. I tried rebuilding mine with some luck, but best was re-sleeve. I spent just as much rebuilding as I would have with a new set of Premieres.

On my old Amals (only 13K miles), the Pazon SureFire helped the idle some, a new anodized slides helped some more, but the re-sleeved slides made it work right. But you still may have an air leak somewhere else. My old carbs didn't respond much to the idle screw either until I did the rebuild/sleeve. Make sure the carb to manifold junction is flat and the o-ring good. Same with the manifold to gasket to head surfaces are flat, and the rubber connecting hose is good. Do not tighten the carb to manifold too tight it will bend the carb body. All been said many times before.

Dave
69S

I follow Dave's logic that the amount of deviation in RPM between cold and warm idle can be wildly exacerbated by that idle speed being right on the cusp of the steep Boyer advance curve. I believe I witnessed that with my worn out carbs.
http://atlanticgreen.com/boyerexposed.htm

DogT said:

If the carbs are old, I would look into re-sleeving. I tried rebuilding mine with some luck, but best was re-sleeve.
.......but the re-sleeved slides made it work right.

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Dear Dave,
thank you.
Please, could tell me the tollerance i need to leave for a good resleeving.
Ciao.
Piero

I don't know, but as close tolerance as can be tolerated without sticking. I sent mine to Lund's in Oregon, http://www.amalsleeve.com/ I choose to re-sleve because I had already replaced everything else. There may be someone in EU that does it, but I don't know.

OK, I did say I didn't know. But can you give Piero a place in EU that can do it? I don't think it would be a home project. Unless he's buying the Premiers, then it's all moot.

DogT said:

But can you give Piero a place in EU that can do it? I don't think it would be a home project.

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I've done it as a home project a number of times. Anyone with a lathe can turn down a throttle slide and fit a sleeve to it. The bodies are rarely worn enough that they need to be bored bigger in the slide bore.
Fit a stainless sleeve and give it 0.0035" clearance at the tightest point.
Then cut/file/grind the cutaway to the same as before, and cut the notch for idle stop screw.

Add up the cost of resleeving, unless you do it yourself, new needle jets and needles, floats, float valves and gaskets. You are probably getting fairly close to the cost of a new Premiere carb.

htown16 said:

Add up the cost of resleeving, unless you do it yourself, new needle jets and needles, floats, float valves and gaskets. You are probably getting fairly close to the cost of a new Premiere carb.

Click to expand...

I did say that earlier. In my case I chose to try simpler things first and it didn't work good enough, so re-sleeving was less expensive than new Premieres at that point, but yes the final bill was about the same. But I had the pleasure of working on the Amals. Invaluable experience.

htown16 said:

Add up the cost of resleeving, unless you do it yourself, new needle jets and needles, floats, float valves and gaskets. You are probably getting fairly close to the cost of a new Premiere carb.

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+1
Piero

DogT said:

htown16 said:

Add up the cost of resleeving, unless you do it yourself, new needle jets and needles, floats, float valves and gaskets. You are probably getting fairly close to the cost of a new Premiere carb.

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I did say that earlier. In my case I chose to try simpler things first and it didn't work good enough, so re-sleeving was less expensive than new Premieres at that point, but yes the final bill was about the same. But I had the pleasure of working on the Amals. Invaluable experience.

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+2
Piero

htown16 said:

Add up the cost of resleeving, unless you do it yourself, new needle jets and needles, floats, float valves and gaskets. You are probably getting fairly close to the cost of a new Premiere carb.

Click to expand...

Zactly how I viewed it, a simple 'rithmatic task, best done before dumping $100 in consumables into oldies.

DogT said:

htown16 said:

Add up the cost of resleeving, unless you do it yourself, new needle jets and needles, floats, float valves and gaskets. You are probably getting fairly close to the cost of a new Premiere carb.

Click to expand...

I did say that earlier. In my case I chose to try simpler things first and it didn't work good enough, so re-sleeving was less expensive than new Premieres at that point, but yes the final bill was about the same. But I had the pleasure of working on the Amals. Invaluable experience.

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Hi Dave,
Andover dont supply the larger throttle valves for resleeving!.
Where i can buy, could be better in Europe.
Thank you.
Piero

There's got to be someone on your continent that re-sleeves Amal slides and bores the body. How about that place in Nederland? I wouldn't let just anyone do it, experience with the Amal should not be hard to find in GB, can Hemmings do it or he may know? Call him or Angie.

You should be able to buy the Premieres directly from Burlin in GB, not to cut into Jerry's shop, but the shipping and import may be more reasonable? Maybe not with VAT.

DogT said:

There's got to be someone on your continent that re-sleeves Amal slides and bores the body. How about that place in Nederland? I wouldn't let just anyone do it, experience with the Amal should not be hard to find in GB, can Hemmings do it or he may know? Call him or Angie.

You should be able to buy the Premieres directly from Burlin in GB, not to cut into Jerry's shop, but the shipping and import may be more reasonable? Maybe not with VAT.

Click to expand...

Dave,
If i could know where i find the larger valves throttle i can do the resleeving at home.
Ciao
Piero