Sleeving Amals...not sure it's what it's cracked up to be (2011)

britbike220 · Apr 6, 2011

Re: Sleeving Amals...not sure it's what it's cracked up to b

Carbonfibre said:
Why mess around with sleeving Amals, when properly made modern carbs will provide better performance and economy, with no need for sleeving as they dont wear out?

My personal reasons are original look, easy to jet. Those New carbs basically need to be dyno'd to get them jetted right. I hate mikuni's because of their billions of jet options and they just don't look right on a "stock" brit bike.

CanukNortonNut · Apr 6, 2011

Re: Sleeving Amals...not sure it's what it's cracked up to b

swooshdave said:
Carbonfibre said:

Why mess around with sleeving Amals, when properly made modern carbs will provide better performance and economy, with no need for sleeving as they dont wear out?

Click to expand...

Why bother with a Norton when there are properly made modern bikes that will provide better performance and economy? :roll:

:lol: Well said
The Amal Mk1 Carburettor “Warts and All” Love em or Hate em … you keep your original filter. And they are simple (KISS principle) to work on. Once your float height is set and Main Jet is correct for WOT Plug chop. Your Needle jet/Needle/ and slide cutaway should not steer too far away from your factory settings, unless you change Bore/Cam/Exhaust/timing or Breather to something other than factory. Just don’t have a Silverback gorilla put them on :shock: … (Over Tighten)… another problem.
Carbonfiber. You can throw money at new carburetors in many ways…. even fuel injection if you wait long enough. :roll: It’s out there. But the Commando responds well to a set of well-sorted Amal Mk1’s. Yes there is a weakness in the design…Brass sleeves solves the problem…Hell even Amal is making Brass/Chrome/Anodized Aluminium slides now…. so they are listening.

Hortons Norton · Apr 6, 2011

Re: Sleeving Amals...not sure it's what it's cracked up to b

Hey Mike welcome back!!!!

Carbonfibre · Apr 7, 2011

Re: Sleeving Amals...not sure it's what it's cracked up to b

If you want to actually ride your classic bike, rather than show or simply just polish it, then modern carbs in common with things like modern tyres are probably a much better choice than OE type parts which wear out very quickly, and are so poorly made anyway they dont even work that well when new.

Carbonfibre · Apr 7, 2011

Re: Sleeving Amals...not sure it's what it's cracked up to b

Carbonfibre said:
If you want to actually ride your classic bike, rather than show or simply just polish it, then modern carbs in common with things like modern tyres are probably a much better choice than OE type parts which wear out very quickly, and are so poorly made anyway they dont even work that well when new!

In terms of cost OKO 32mm flatslide carbs of the type often marketed in the US with the OKO branding removed, are likely to be less than half the cost of other alternatives, and are very easy to set up and tune.

MexicoMike · Apr 7, 2011

Re: Sleeving Amals...not sure it's what it's cracked up to b

Thanks! Back due to proxy server!

I guess we can do this AMAL thing to death but they worked fine on my original 71 750 until I sold it in 78. Tuned up they will idle smoothly at 600RPM and they produce all the air/fuel that a Commando motor can handle, at least as modified up to/including the original Norton-published stage II tuning.

OTOH, I will admit that if Mikuni made a copy of the Concentric, I might consider one when these Amals are worn out!

swooshdave · Apr 7, 2011

Re: Sleeving Amals...not sure it's what it's cracked up to b

MexicoMike said:
Thanks! Back due to proxy server!

I guess we can do this AMAL thing to death but they worked fine on my original 71 750 until I sold it in 78. Tuned up they will idle smoothly at 600RPM and they produce all the air/fuel that a Commando motor can handle, at least as modified up to/including the original Norton-published stage II tuning.

OTOH, I will admit that if Mikuni made a copy of the Concentric, I might consider one when these Amals are worn out!

Mukuni did make a copy of the Amal, but it was the MkII. So in some ways having a Mukuni isn't a complete travesty. :mrgreen:

Carbonfibre · Apr 7, 2011

Re: Sleeving Amals...not sure it's what it's cracked up to b

The VM Mikuni was in point of fact designed and manufactured before the Mk1 Amals, so it would appear Amal did the copying, but unfortunately didnt do that good a job!

montelatici · Apr 7, 2011

Re: Sleeving Amals...not sure it's what it's cracked up to b

Carbonfibre said:
The VM Mikuni was in point of fact designed and manufactured before the Mk1 Amals, so it would appear Amal did the copying, but unfortunately didnt do that good a job!

Racing 2-stroke Yamahas I gained a lot of experience and respect for the VM Mikuni. Of course, I have hundreds of slides, jets, needles, tools and spares that you get when you bought a race tuners kit decades ago, so that helps a lot when you are trying to sort out carburetion, plus you don't worry about the idle on a race bike. On the other hand, I have never had problems with the Mark 1s, I guess I've been looky.

swooshdave · Apr 7, 2011

Re: Sleeving Amals...not sure it's what it's cracked up to b

Carbonfibre said:
The VM Mikuni was in point of fact designed and manufactured before the Mk1 Amals, so it would appear Amal did the copying, but unfortunately didnt do that good a job!

Just some guy on the interweb so no validation but some interesting comments.

http://xs650temp.proboards.com/index.cg ... hread=7499

Re: VM needle jet theory
Post by mercurymorse on Jan 17, 2006, 3:47am

Ah, the dreaded MIK round slide primary VS. bleeder N/J quandry. First, a little history. Few know that the MIK is a rejected Amal design. When Amal was looking to replace the Monobloc, the MIK was one of the the candidates (Concentric MK1 won). However, with a N/J mixes the Air Correction air AFTER the fuel is metered ( Primary N/J), it will not tilt the fuel/air curve enough for a 4 stroke. A good 2S carb, so Amal licensed it to the Japanese. The early YG1 Yamaha carbs still had the Amal logo on them. This lack of F/A tilt means that to properly jet for top end, the mid range (at full throttle) is always too rich, costing you about 15% horsepowerwise, according to MIK. The Bleeder N/J is MIK's attempt to correct this deficeincy. The A/C jet becomes VERY critical. My experience has been that the Needle, N/J, M/J and A/C jet become much more of a combo, making jetting from scratch very difficult. To a certain extent, change one, and it messes up the other 3. While experimenting, admittedly under the duress of racing, I made over 200 brass changes and never got it right. It was still better than a Primary N/J, and I won races, but I finally gave up, and bolted on Amal MKII Concentrics, and won the first race, even though it was way too rich everywhere, primarily due to the as-delivered spray bar height adjustment. Throttle response was outstanding, and I run Amals to this day, in spite of their headaches. I may revisit the Bleeder N/J dilemma on the MX project, as I don't have any Amals small enough, but not without a dyno and EGA.

79x100 · Apr 7, 2011

Re: Sleeving Amals...not sure it's what it's cracked up to b

Carbonfibre said:
If you want to actually ride your classic bike, rather than show or simply just polish it, then modern carbs in common with things like modern tyres are probably a much better choice than OE type parts which wear out very quickly, and are so poorly made anyway they dont even work that well when new.

My Nortons are ridden. One of them's polished and one isn't but that has nothing to do with anything. Have we seen a picture of your Commando yet Cf ?

I'm with the poster who says that Miks don't look right on an otherwise stock Commando. I also enjoy the 'tickling' ritual. I enjoy shaking my head in disbelief at those who say Concentrics can't be made to run properly or that twin Amals are impossible to keep in tune.

Perhaps I'm in a minority in that I'm happy with the performance of my Commando. I find the acceleration crisp and the power adequate. I like it for what it is, which is coincidentally a piece of cultural and social history. On a lower scale, I'd rather support cottage industries in the UK than giant corporations in Japan (where we're now finding that the industrial miracle might just have been built on cheap power and cutting corners on safety).

I like being able to talk to people like Martin Bratby and the chaps at Burlen and if I wasn't prepared to accept design compromises then I wouldn't have stuck with a Commando for most of my adult life.

There is an increasing trend on this forum of 'those in the know' constantly criticising the choice of others rather than being helpful. This negativity is not something that I'm completely comfortable with.

gtsun · Apr 7, 2011

Re: Sleeving Amals...not sure it's what it's cracked up to b

Choice is the owners perogitive. I'm no carb expert but years ago when I had 750's I allways had dual Amals and even as a teenage novice with no help but a book I set them up myself and to this day the smoothest running most responsive Commando I have ever ridden was with those Amals. That bike would idle like a clock and I could glide at two miles per hour smooth as silk or blast around as much as a old bike should. My current 850 came with a Mikuni and while it runs good, starts first kick etc I do not think it idles as smooth or accelerates as good. I know nothing about this carb but it was set up by a very experianced Norton guy who loves them so I'm sure it's set up correctly, but what I do know is it is truely ugly and needs to be replaced by two Amals. I'm willing to bet my bike will be just as powerful and I will like the look much better.

batrider · Apr 7, 2011

Re: Sleeving Amals...not sure it's what it's cracked up to b

+1 to that 79x100. It scares me that some of this "in the know" info is just whatever is repeated the most on the internet. Especially the advice when it comes to newbies building bikes with all these must have so-called upgrades. Yeah I know... cranky old guy.

MexicoMike · Apr 7, 2011

Re: Sleeving Amals...not sure it's what it's cracked up to b

"Perhaps I'm in a minority in that I'm happy with the performance of my Commando."

Well, there's at least two of us!

I'm TOTALLY in favor of getting the best power/performance out of my Commando within its limits as it was originally designed. But I am not interested in trying to make it run with a current Ducati. Heck the new Commando can't do that and it's "all new!"

I like the bike to look/act/sound pretty much like it did new though I will admit I didn't hesitate to upgrade the brakes to a Brembo MC so my handlebar area (MCylinder/switchgear) is not original. A few months ago I pulled the Brembo MC and put the Miles-sleeved oem MC back on because I wanted the original switch gear. But the braking performance of the sleeved oem, though a big improvement over stock, is just not up to the Brembo and I couldn't deal with it after being used to the Brembo so I put it and the non-oem switch gear back in place.

IMO most "upgrades" aren't. But I have to admit that I think the front brake upgrades really are!

xbacksideslider · Apr 7, 2011

Re: Sleeving Amals...not sure it's what it's cracked up to b

In terms of performance, tunability, and their ability to perform/adapt despite change in altitude, both the Concentric and the MKII are excellent carbs.

The penny pinching change to the zinc slide, made when the Concentric replaced the Monobloc, is the root of all evil, at least within the world of Amals.

If only Lucas had fixed that awful POS auto advance and if only Amal had retained the Monobloc's chromed brass slide . . . . . . then, maybe, the Brit bike makers could have survived.

batrider · Apr 7, 2011

Re: Sleeving Amals...not sure it's what it's cracked up to b

I' used a single 34mm Mikuni for a few years then went to dual 34mm Mikunis for another bunch of years and eventually went back to the Amals. They have the best overall performance in my book. Also I wanted to go back to a stock look.

Besides the slides, the Amal needles and needle jets don't last long. I had the carbs sleeved by Bruce at Triton and have run that way for a number of years with no sticking. Needles and needle jets are replaced every 5000 miles or as soon as it starts stammering at constant speed in 2nd gear around town. I think a 105.5 needle jet would be the perfect thing for Burlen to make if they can really control the tolerances. There is a huge difference between a 105 (way too lean) and a 106 (very close to too rich when new).

I also lost the AA unit early on. POS is being kind. Mine hammered the stops to death. Maybe they are being made better now.

I don't put big miles on mine anymore so the maintenance is now a little less than constant.

Carbonfibre · Apr 8, 2011

Re: Sleeving Amals...not sure it's what it's cracked up to b

The VM Mikuni carb is what Amal looked at before making the Concentric, so these carbs are pretty dated, and while being of far higher quality than the pot metal Amal's, and likely to last far longer, they wont provide the type of performance gains to be had from a modern flat slide set up.

In the US it seems that the excellent Taiwanese OKO flat slide carbs are commonly being sold with OKO branding removed, for around double the normal selling price in other parts of the world! Anyone able to find a source of these carbs at the proper price, and a couple of flange to spigot type adapters, is going to have a very good set up for less than half the price of Amals, with no need to mess around with sleeving etc when they wear out!

JAYMAC · Apr 8, 2011

Re: Sleeving Amals...not sure it's what it's cracked up to b

Carbonfibre said:
The VM Mikuni carb is what Amal looked at before making the Concentric, so these carbs are pretty dated, and while being of far higher quality than the pot metal Amal's, and likely to last far longer, they wont provide the type of performance gains to be had from a modern flat slide set up.

In the US it seems that the excellent Taiwanese OKO flat slide carbs are commonly being sold with OKO branding removed, for around double the normal selling price in other parts of the world! Anyone able to find a source of these carbs at the proper price, and a couple of flange to spigot type adapters, is going to have a very good set up for less than half the price of Amals, with no need to mess around with sleeving etc when they wear out!

I have used Amals on all the Commando's and other British bikes I have owned over the past 40 years, including my current MK3 Roadster. I have never had a problem getting them set up correctly and my MK3 will start 1st kick(sometimes 2nd) from cold and tickover evenly once it is warm, acceleration is crisp and performance is good for a 35 year old bike. Although I really don't see any point in going much over 80mph, this is not what these bikes are about, I have a few modern bikes which are much more suited to fast riding. These include a New Commando 961 Sport which is superb and obviously no comparison to my old Commando's being better in every department, performance, handling and braking as you would expect.
However I have to agree the Amal carbs do wear rather quickly and if you don't mind having a non standard looking Commando the modern options will perform better and last longer.

daveh · Apr 9, 2011

Re: Sleeving Amals...not sure it's what it's cracked up to b

Mike, I'm kinda with you on this. I re-sleeved a pair of Amals myself using seamless brass tube epoxied to the slides and bored the bodies to true cylinders. BUT, it was one hell of a job on my small lathe and I wouldn't do it again. I feel it just delaying the day when I have to scrap the carbs and buy new. Yes, the mod worked but for how long? A new set of bodies (no need to buy a complete carb if the rest is OK) and chromed brass slides is not mad money and that is what I would go for when these carbs wear out. One then has a set of carburettors that may be rather primitive but are easy to tune and maintain and you can retain a paper element air cleaner which I think is better than a K&N. I would like a set of Keihins that Jim Schmidt at JS Motorsport sells and I have no doubt they are superior, but I can't justify the cost right now.

Dave

britbike220 · Apr 9, 2011

Re: Sleeving Amals...not sure it's what it's cracked up to b

I've used sleeved carbs for about 8 years w/o noticeable wear. So at the price I paid to have the sleeves done I am miles ahead of a new set of any modern carb and since I am not a racer I also don't require superior performance.

Sleeving Amals...not sure it's what it's cracked up to be (2011)

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