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Best value for money carbs - restored Amal MK1 ?
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Per G



Joined: 07 Apr 2008
Posts: 66
Location: Sweden

PostPosted: Tue Aug 19, 2008 3:55 am    Post subject: Best value for money carbs - restored Amal MK1 ? Reply with quote

Talking about best carbs for the money I vote for a pair of restored Amal MK1.
If they are properly re-sleeved, the idle circuit is 100% clean, correct float height setting, and they are synchronized (using Carbtune or similar equipment) I think you have a great carb set-up for the money.

It takes a good portion of patience to get there but when properly done the MK1 works. I finally got mine sorted out and the bike now has a solid idle, great throttle response, pulls nicely from idle and up.
I can drive 25 mph on top gear, twist the throttle and it pulls without any hesitation Very Happy
And I run with a slightly modified original points system.

Cheers,
Per
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blaisestation



Joined: 10 Apr 2008
Posts: 8
Location: berlin x berg germany (ex NZ)

PostPosted: Wed Aug 20, 2008 2:59 am    Post subject: Reply with quote

Hello Per
where did you have your re sleeving done and could you let me know the cost please ? any information would be helpful.

Tak and cheers Blaisestation
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Per G



Joined: 07 Apr 2008
Posts: 66
Location: Sweden

PostPosted: Wed Aug 20, 2008 7:42 am    Post subject: Reply with quote

There is a member of Norton Sweden that is doing the re-sleeving for most people here. I believe he has done at least 30 pairs so far and he is doing a great job.

If you are interested I can help you with the contacts. You can send me a PM if you want to know more on pricing etc.
The only disadvantage is that he is only doing one batch per year so you have to send him the carbs in early November and then he will send you a Chrsitmas present Very Happy

/Per
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worntorn



Joined: 22 Dec 2006
Posts: 168
Location: Langley, B.C.

PostPosted: Wed Aug 20, 2008 9:20 pm    Post subject: Reply with quote

I agree Per, Concentrics work fine, especially after rebuilding with brass sleeves on the slide. I have three bikes with MK1 concentrics, two Nortons and a Vincent twin. The Commando and the Vincent twin have not yet been sleeved, but that is the route I will take when the slides get badly worn. The third bike is the 650SS that I just bought, it has been sleeved in brass. All three are almost always one kick starters, all three idle perfectly and pull smoothly thru the range.

Several of my fellow Vincent club members have informed me that Concentric MK1 carbs are junk and that I should switch to Mikunis for better performance and easier starting. In my admittedly limited experience, I have found the opposite.
My fourth bike is another Vincent Rapide. It has the benefit of having new Mikuni carbs. It runs well, but does not start as easily as the other three. It is also a bit slower than my Amal equipped Rapide, even though the bike with the Mikunis has higher compression and hotter cams.
I'm reluctant to change the carbs on any of the bikes fitted with concentrics, they all run so well.
I have considered changing the Mikuni equipped bike to Amal concentrics.

I have heard it said by others that the carb tickler on an Amal, though annoying to some, is a very positive way to supply a necessary shot of gasoline to start a cold engine. The enrichening circuit on a Mikuni does not seem to work as well for this purpose, at least mine doesn't.
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Per G



Joined: 07 Apr 2008
Posts: 66
Location: Sweden

PostPosted: Thu Aug 21, 2008 12:29 am    Post subject: Reply with quote

I'm not traying to say that changing to other carbs is wrong but I think more people would keep the original carbs if they got them sorted out properly and by doing that save money and keep the original look Smile

It is a lot cheaper to fix the Amal's compared to buying new carbs (regardless of make) and with the brass sleeves they seem to last "forever".
The MK1 is easy to work on and I think many people get problems (idle, starting etc) due to the difficulty to get the idle circuit properly cleaned out. With idle circuit clean I think it works great!

Regards,
Per
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worntorn



Joined: 22 Dec 2006
Posts: 168
Location: Langley, B.C.

PostPosted: Thu Aug 21, 2008 8:17 am    Post subject: Reply with quote

Nor did I mean switching to Mikunis or other carbs is wrong, it's just that as you say,there is no need to!
In my own case the one set of Mikunis I have came with on the bike, so I was interested to see how it ran in comparison to my Concentric equipped Vincent. After all of the strong advice I had been given by my fellow club members who insist that Amal Concentrics are crappy carbs that will not meter the gas flow properly at anything under full throttle, I expected the Mikunis to give superior performance, easier starting and smoother running than my Concentric equipped bike.

One fellow was quite insistent about my need to throw away the Concentrics as part of what he claimed I needed to do in order to make my Vincent "make power" like he claimed his did. His is heavily modified with 9.4 to one pistons, Lightining cams, Harley Screaming Eagle ignition, ported intakes and exhausts, large diameter headers, Supertrapp exhaust, huge twin 36 MM flat slide Mikunis, five speed Quaife and some other stuff I have forgotten.

Every time we met he would start in on my need to "spend some money on the bike and make it competitive".
Along with several other Vincents, we ended up riding together on a 3.000 mile trip to the southern US and home. In Idaho on a six mile long 10% grade he took off on his hotrod Vincent, passing the Group leader. We were both two up with gear, but my bike was loaded about 50 pounds more heavily than his. I decided to give chase and to my surprise managed to catch him and pass! He damn near fell of his bike when we cam up alongside. He later claimed that he could have dropped one more gear and caught us, but I think not! He said he didn't want to frighten his wife, pure BS., with his riding (fast)he had her scared out of her wits most of the time anyway!
Six months later we got into again at a Rally in central washington.
Again he passed our ride leader and I gave chase. This time we were solo and the speeds were greater. I caught him at something over 100 mph and backed off just a little to stay alongside, then opened the throttle and slowly pulled away!

He no longer tells me that I need to spend money on the bike to "make power" or that I should junk my carbs!



Initially the Mikuni equipped bike ran poorly at high RPMs but with several main jet changes that is no longer a problem. It runs just fine, as well as the other bikes but no better, but is sometimes difficult to start whereas the others are not. I remain uncovinced that the Mikuni is a better carb for these bikes, other than the slide, which as you say can be rectified by sleeving.
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Jason Curtiss



Joined: 14 Jun 2003
Posts: 661
Location: HOUSTON, TEXAS

PostPosted: Thu Aug 21, 2008 8:46 am    Post subject: Reply with quote

I, too, think highly of the AMAL carburetor (with the chrome brass slide). Heck, I even like the name. The AMAL performs well and is dead simple to work on and tune.

Jason
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iusedtolikehondas



Joined: 22 Jun 2008
Posts: 36
Location: napa ca

PostPosted: Thu Aug 21, 2008 10:14 am    Post subject: Reply with quote

where do you make the call to have them sleeved? i have read that if there is any shiny spots in the slides, this is an indication on wear.

when i took mine apart for inspection, there is some slight evidence of this, but it seems to run good.

there are only 4k miles on the bike, it did sit for 25 years, but the age also plays a role?
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79x100



Joined: 19 May 2006
Posts: 689

PostPosted: Thu Aug 21, 2008 11:03 am    Post subject: Reply with quote

I've always been pleased with Mk1 Concentrics and have set them up to run with various exhaust and air filter systems without difficulty. My current set were sleeved by Martin Bratby in the UK.

There has long been the idea that twin Amals are 'difficult to keep in tune' - I don't get it really. There are only two screws and a cable adjuster on each carb.

Back in the seventies, it was always said that Amals flowed more than Mikunis of the equivalent bore size. I don't know if this is true when compared with later versions.

On the subject of resleeving, I think it's true to say that you'll know when you need to ! The slide will be worn with groves on the thrust faces and if you grasp the slide through the carb openings, you'll be able to appreciably rock it back and forwards. If a new slide does the same, then it's time. On a properly filtered engine, I would expect 20,000 - 40,000 mile before it needs sleeving.
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Per G



Joined: 07 Apr 2008
Posts: 66
Location: Sweden

PostPosted: Thu Aug 21, 2008 11:45 am    Post subject: Reply with quote

The guy who did my carbs told me that new Amal's has a too large clearance so even the new carbs would benefit from the re-sleeve mod.

It seems to be a good idea to perform the "Modification for blanking screw" proposed on Bushman's carb tuning secrets. This will make the idle circuit cleaning a lot easier. This mod is on my to-do-list for this winter wrenching!

Regards,
Per
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2ndchildhood



Joined: 13 Sep 2006
Posts: 13
Location: Northern California

PostPosted: Thu Aug 21, 2008 12:18 pm    Post subject: Reply with quote

iusedtolikehondas wrote:
where do you make the call to have them sleeved?


AMR in Arizona and Lund up in Washington both provide this service.
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iusedtolikehondas



Joined: 22 Jun 2008
Posts: 36
Location: napa ca

PostPosted: Thu Aug 21, 2008 1:47 pm    Post subject: Reply with quote

2ndchildhood wrote:
iusedtolikehondas wrote:
where do you make the call to have them sleeved?


AMR in Arizona and Lund up in Washington both provide this service.


thanks for the info
i guess i worded the question wrong, i meant what to look for. but i'm pretty sure mine are fine after looking at them again.
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Jason Curtiss



Joined: 14 Jun 2003
Posts: 661
Location: HOUSTON, TEXAS

PostPosted: Thu Aug 21, 2008 3:21 pm    Post subject: Reply with quote

Note that AMR in Arizona provide a complete, chrome plated brass slide.
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norbsa48503



Joined: 07 Apr 2004
Posts: 995
Location: Flint, Michigan

PostPosted: Thu Aug 21, 2008 4:34 pm    Post subject: Reply with quote

Jason,
Please be careful who you give that advice to. This man (Per G) is in Sweden and will most likely need a choke from time to time. I believe the AMR mod does not allow it.
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Per G



Joined: 07 Apr 2008
Posts: 66
Location: Sweden

PostPosted: Fri Aug 22, 2008 1:39 am    Post subject: Reply with quote

Yes, we need to use the choke (especially during spring and fall seasons) and I also like to have it for testing.

The mod I have on my carbs is very similar to the mod done by "Lund".

Regards,
Per
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The Unapproachable Norton Commando

At the end of 1967 the Norton Commando was announced.

The Norton Commando was greeted with a certain amount of scepticism because on first sight the commando appeared to comprise of the old Norton Dominator twin cylinder engine mounted at an inclined angle in a set of new cylinder parts.

It was not realized that the new Norton Commando Isolastic method of engine suspension damped out all engine vibration and produced a machine which had uncanny smoothness for a vertical twin. In due course the critics were silenced and the Norton Commando had the distinction of being regarded as the first of todays so called superbikes. There can be little doubt that the original design concept of the Norton Commando has proved correct, since comparatively few modifications of any real consequence have been made since production commenced during 1968.

Now nearly 40 years later Norton Commando riders like us are a breed of our own, and as far as we are concerned its still more fun to go for a blat on the old Norton Commando, and fast. As a Norton Commando owner and enthusiast, my goal here is to promote and give credit to those who keep the Norton name going.

It is more deserving to give credit to the Commando itself, for after all these years it continues to be respected. The original Commando designers like John Favill are those who deserve the credit for developing this incredible motorcycle.

The Norton Commando Roadster and Interstate of the late seventies, never died. Although the Norton Villiers factory dispersed the tradition lived on. Today Kenny Dreer in the USA is developing the new 952 CC Norton. What a great looking bike this is, and its engineering is still based on the original layout. It will be interesting to see how the new 952CC Norton does in todays tough motorcycle market. One thing is for sure, I would own one if I could afford it.