Amal Settings

Nellie_Rocks said:

Hey Willy Mac:

I stripped my Amals down at the beginning of this year and cleaned all the 'wee' holes out with carb cleaner and wire, made a big difference.

However ..... I still find I'm tweaking the carbs (pilot / mixture screws) dependent on climate. It gets warm in Northern California during the summer requiring one set of tweaks and has now cooled to require a different set. I think over time, and my bike has 24,xxx on it, the slides and bores become worn and getting a reliable tune becomes more challenging - I'm thinking of the anodized slides as the next change.

I have not been able to get the bike to a reliable tickover below 1,000 revs and if I can get it to a point where it doesn't cut out when I come to a stop, I'm (relatively) happy. Oh, and I'm running Boyer ingintion.

As I say, I think the main issue is air slipping by the slide / bore surfaces, leaning out the mixture. I'm running with the needles one step down, so a relatively rich mixture.

Just my experience, from a novice spanner-juggler.

BTW - I'm from the UK and the grandparents grew up in Mofat, Dumfriesshire - I'd love to ride around the west coast some day, truly God's country.

- Nellie

Click to expand...

Aye Nellie, the West coast of our bonnie land is a braw place to be on a bike, my son and me went over to Skye from Mallaig at the start of the summer and caught one of the best weekends of the year. But could do with some spare sun from your part of the world.

My Carb at this time has less than 600 miles on it at the moment so worn bore and slide has yet to come!

[/quote]My steady tickover is around 900-1000, but I can't really put a finger on, when it'll cut out when rolling to a stop, or when testing it on the move(Coasting), as sometimes it will and other times it won't.
As I have the 2-1 inlet manifold the heat insulating blocks that are normally there with the individual manifolds can't be used so I'm wondering if this might have something to do with it as the heat transfers through to the carb?
The studs on the manifold used to secure the carb are not long enough to have a thick insulating washer in place but this might be a necessary modification if it turns out to be a heat transfer issue.[/quote]

it has always been my understanding that heat insulating the carbs is mandatory. As heat transferes from head to carb, the result is the bike has a more and more difficult time to idle. My experience was in my Old 1952 moto Parilla, it had a solid mounted carb and it ran great but refused to idle after warmed up. Once an "old" guy told me i need to insulate the carb....I made a phenolic spacer (.250" thick) to put between the manifold and head....and I had to put longer studs in. That was the solution,bike ran perfect after that.
the commando 2 into 1 manifold does have a spacer/insulator available, i think putting one in will resolve your idle issues

What is the advantage of a ultra low idle say 700-800? I would be concerned about low oil pressure. I have the idle set at around a 1000-1100 on all my bikes including the Sportster which is factory spec. On my BSA when the idle drops really low the oil pressure light will flicker on and off. I'm told that is fairly common for those bikes. It seems like if you can shift into first without a distinct crunch what does a little higher idle hurt.

htown16 said:

What is the advantage of a ultra low idle say 700-800? I would be concerned about low oil pressure. I have the idle set at around a 1000-1100 on all my bikes including the Sportster which is factory spec. On my BSA when the idle drops really low the oil pressure light will flicker on and off. I'm told that is fairly common for those bikes. It seems like if you can shift into first without a distinct crunch what does a little higher idle hurt.

Click to expand...

No advantage other than the pa plop, pa plop, pa plop, pa plop sound may have some subliminal pleasing effect. Like that of a heart beat on the verge of ecstasy.

I don't know, what does the pa plop, pa plop, pa plop, pa plop sound say to you?

Well, I lived in the country for a while surrounded by cows.

htown16 said:

Well, I lived in the country for a while surrounded by cows.

Click to expand...

That's sort of a Texans romantic view of life. Yes, No?

the commando 2 into 1 manifold does have a spacer/insulator available,

The Heat insulator/spacer you are referring to for the 2-1 manifold! does it fit between the head and manifold or is it one of the originals fitted between the manifold and carb?
I've found some with RGM and Norvil but I'm thinking they are for the original individual manifolds, I suppose one of these would do the job mounted between the manifold and the carb.