Forum

[Exile]

I can't help but wonder.. why are people so obsessed with the idea that fitting an amal will so vastly improve something that was designed, built and fitted with a micarb and ran sweetly straight out of the box...??


No insult intended and no offence meant. But...Did I miss something?

[Edward]

No, Exile, you didn't miss anything. Those who missed something wasted money on an Amal.

[Presto]

For my part I’ve never understood the barrage of criticism that’s aimed at the Amal Concentric. If ever a product has proved its worth by what it does - and not by theories that are thrown around in chatter - that product is the Amal Concentric Mk1!



The thing has been fitted to countless thousands of engines since it first saw the light of day and has been used with outstanding success for everyday road use, road racing, motocross, speed trials and timed trials, grass track racing, go-cart racing, etc. It is simple, inexpensive, easily tuned and readily available. Credit where credits due.

[Revband]

+1 on that, but the monobloc was better

[Edward]

I understand the barrage of criticism. The concentric was a carb built down to a price under pressure from British motorcycle manufacturers, the slightest of overtightening of the flange will distort the barrel and when the slides were the same material as the body the wear rate was ridiculous and could cause the throttle to jam open. Amal can make superb carbs bit the concentric is not one of them. As for use on competition motorcycles very few came with a concentric as standard.

[Adrian]

The original Mk1 Concentric's vices were acknowledged when the current producers of the Amal carb brought out the Premier version, though I see on our hosts' listings the original version is still available at about £20 cheaper. If I were to revert to a Mk1 on anything it would be the premier version with better alloy and several other improvements. There's also the Wassell copy of the Mk1, has anyone used one of those successfully?



The Mk2 Concentric has its supporters and can still be seen on bikes in classic race paddocks amongst the inevitable Mikunis (and Dell'Ortos, sidecar fans!).



A.

[sofiaspin]

Currently trying to sort exactly the same problem on my 08 classic. Similar set up except for points. Put in new Motobatt battery, condenser, cleaned out and stripped Mk1 Amal (only 3 years old) all wiring fine, ignition working perfectly after strobe test, new plug, new fuel after draining tank, valves opening correctly. Splutters, backfires through carb and pops, have to hold throttle open to keep it running when it catches. All signs of lean running but it was fine when put away in shed. New coil goes in tomorrow plus new points albeit points were hardly used. My mechanic is now on the case and will put it on the dyno, he is convinced it is a carb problem yet the carb was working perfectly. Same carb on my Electra X goldstar rapido and the bike flies! Enfields.........but it is all logic, and well,,,,,,,who knows. A failing coil can mask carb problems. I took this bike for 5000 miles last year and it ran perfectly, now it is a PITA!

[Adrian]

THE problem with an otherwise working Mk1 concentric seems to be the dreaded blockage in or around the pilot jet, which is a fixed bush on the older style carbs (not the Premier, which has a proper detachable jet), I think Paul Henshaw amongst others worked out a way of getting in there to clean things up. I will see if I can find where he posted what he did and post a link.



A good fuel filter is probably not a bad idea if you don't already have one.



A.

[Leon Novello]

As with Exile and Edward, I agree, why change things that work? Bullets are not speed machines.
It`s creating problems where none existed before. My Bullet`s engine was stock standard for seventeen years and never had trouble keeping up with motorway traffic. There is enough to keep anyone busy when normal wear and tear occurs.

[sofiaspin]

People bin the Micarb for the same reason they bin lots of other bits on an Enfield - because they want to personalise their bike. One compelling reason is the Amal looks the part and hence whilst as Adrian says, the dreaded pilot jet can get blocked, the Amal just looks so much better. As to function, I have had many of them on Enfield's, Velos, Triumphs etc and never once had a problem. Modern fuel is a major headache. Useful to know the Premier has resolved the pilot jet problem.