Painted Amal?

[duTch]

Ditto that Richard, I've had in mind to ask same, after call to John Phelan who does 'Cast iron hi-flow' oil pumps, as comparison, and I did see your earlier post but in time to respond then.

Cheers duTch

[BSA_54A10]

A very similar zinc based alloy though not exactly the same should have a bit more copper in the oil pump.

Sorry to go off a bit but there is nothing wrong with alloy selection it was then & still is now the best alloy for that purpose.
The Mikuni is made from exactly the same alloy although today probably with tighter specifications as analytical tooling is much better.
As is ( or was ) the monoblocks  which I believe to be a much better carb.
I used to make remelt foundry ingots in a previous life so repetition of such statements does tend to "push the button".

As for casting & build quality you will get no argument from me there. I have no doubt that some were a lot better than others.
But as for longevity, your concentric may have only been good for 10,000 miles but I have had a lot go a lot longer than that with no great troubles, so SOME might only go 10 K not ALL . There are a lot of Beesas out there still running the came carbs as they left the factory with 60 years ago.
And yes the design could have been better.
My pet hate is the positioning of the cable & needle so that water running down the cable ends up in the float bowl

[Triton Thrasher]

Sorry to go off a bit but there is nothing wrong with alloy selection it was then & still is now the best alloy for that purpose.
The Mikuni is made from exactly the same alloy

Ok, but what do, or did Mikuni make the throttle slide from?

[warmshed]

hard chromed brass? lovely.

Friend has had two new slides break up on his Venom, first was with a new concentric and the replacement also broke up, hes gon back to a monoblock, I prefer the Mikuni.

[Sparky]

Amals definitely seem to be a "hot button" topic. I was reading another similar (but much more contentious) discussion on a Norton forum about the attributes and faults of Amals.  As a follow up of my original post, I followed Trevor's suggestion and boiled the carb on the stove.  It produced a nice pot of tea-colored water, but didn't do much to the oxide coating.  However, the glass bead blaster did a nice job cleaning it up without doing any damage to the metal.  It looks like new!  I found the slide to be somewhat scored and slightly out of round, so have replaced it with a spare.

I never had any problems with this carb (a Monobloc) in around 12,000 miles of riding, and don't expect any once the bike is running again, and since I'm going for the vintage look I don't plan to replace it.  I will say that a friend put a Mikuni on his Triumph, and it runs great and ticks over at idle like a watch, so that is certainly a good option for some people.  Having my finger smell of petrol from the tickler may not be very high tech, but I don't mind.

[Rocket Racer]

I must admit I've always felt amal carbs improved in design while regressing in build quality. My 10TT9 carbs on the road rocket are things of beauty, brass fittings, substantial. Love em.
 

However in addition to risks of overtightening the concentrics do also suffer if not running decent air filters. The slides being only supported by the carb body (non having a slide block to support the ID) dont like dirt and once worn can hammer about making an audible clocking noise.

If I have a carb with the original finish I do try not to disturb more than a clean with mild solvents, dunno if its paint or not.

[warmshed]

It seems monoblocks are not as prone as concentrics to slide break up.  I see you can get carbs bored and chrome plated slides. I assume this allows you to keep original looks, important to some, and reliability?  Anyone gone this roiute?

[Rocket Racer]

It seems monoblocks are not as prone as concentrics to slide break up.  I see you can get carbs bored and chrome plated slides. I assume this allows you to keep original looks, important to some, and reliability?  Anyone gone this roiute?

Back in the eighties (when carb parts were hard to obtain in the colonies) my separate float bowl (289?) carb was sleeved with what I believe is teflon and the thin brass slide soldered back to size.
Its still in this state now! this is on my ZB33. Still going strong
But at least now new early amal parts are back albeit not cheap. should get a new slide some time...

[duTch]

My mate Kel re-sleeved my 389 Mono slide with a stainless sleeve several years ago,and it worked good, but haven't used it a lot since but hope to soon, but will give an update then, cheers duTch

[iansoady]

When I was at Tony Cooper's we had a chat about carbs, and he has all his monoblocs sleeved (ISTR he said it was about £50 / carb). The way his Ariel HT3 and Dommi started first kick and idled like clocks had me convinced to go down that route next time I'm looking at one in poor condition.

[Sparky]

I'd love to have a 10TT9 since that is what was original on the '54 Road Rocket I'm rebuilding, but alas somewhere in the bike's past, a previous owner put on the 389.  I periodically look for them on ebay but anything worth getting is $$$$$