Selecting amals for my mk3

Gidday.
I spotted a really nice mk 3 in the uk for sale that had the red,white,blue colors on his bike and the guy had a fastback tank seat side cover conversion going on. What really appealed to me was the older concentrics and air cleaner assembly.
Like most bikes, mine has the single mikuni conversion but it never looks right.
I don't like the dreaded "stink finger" from tickling old mk1 concentrics but I've read a bit about mk1.5 amals and mk 2,s.
I am keen to get the amals and air box from the earlier models on to my mk3.
Has anyone fitted the older ones to a mk3 and is there a problem with brackets and other stuff getting in the road. All the old electrics have gone and everything is modernized in that department. I need to also hear please of which Amal models will work best with this setup.
Before I buy the parts, it would be great to know if it's reasonably simple or a nitemare.
Cheers hillbone

At the risk of copping flak on the subject once again I bring the SU carby into the debate
It's documented Norton planned putting this on the Commando before going into receivership
My 77 model had one on it but I am unsure if this was a factory accessory though the age of it matched the rest of the bike
I can not fault the SU. It performs admirably with no fuss as well as looking the part and providing excellent MPG
Jack Ahearne has seen it on my bike and commented it certainly looks right
There are a few posts on this site about the carby (the HIF6 is correct for this model) and provided you aren't into breaking standing quarter mile or race speed records you could do a lot worse
Finding the adaptor plate could be a problem though but if you do a K&N 8090 pod filter is the most suitable

one post to view is below
carb-conversion-t10144.html

Good luck

Grasshopper

Ah grasshopper!
Thanks for the reply. I guess the question is more about fitting the original air cleaner from a mk2 commando to a mk3 using the best amals. I know the mikuni works well , but it doesn't look the part.
Cheers mate.

hillbone said:

Ah grasshopper!
Thanks for the reply. I guess the question is more about fitting the original air cleaner from a mk2 commando to a mk3 using the best amals. I know the mikuni works well , but it doesn't look the part.
Cheers mate.

Click to expand...

I am doing the same to my Mk3. I am starting with a battery box from a '72, but any battery box up to, but not including, the Mk2a will work, they have the two lower air cleaner backing plate threaded holes. This will also allow you to fit a pre Mk2a left side cover, which mounts a whole more solidly than a re-purposed Mk2a or Mk3 cover; the hole for the duze fastener is still in the gusset just underneath the backbone, you will need the covers' upper rear mount to complete the three point mounting system; the gusset also has the hole for the upper backing plate mount, the one that uses a spacer.

I am not sure how your electrics will tolerate this change as I re-wire the Nortons that I turn out, but IIRC your only concern will be the CCA rating of the battery that you do end up with. I like to use the Cen-Tech AP-1 fuse panel to keep the circuits separate and will be looking at an Li battery to share the battery box space.

Bill.

hillbone said:

I don't like the dreaded "stink finger" from tickling old mk1 concentrics

Click to expand...

1973-on Mk.1 Concentrics have extended tickler buttons which keep fingers clear of the fuel.

A tickler conversion kits are available for earlier carbs.

http://www.classicenglishmotorcycles.co ... mal/Detail

I have a 1974 Mark IIA and I replaced the plastic airbox with an earlier 'ham can' style air filter. I had to modify the original battery tray in two different ways. First I had to drill 2 new bolt holes for the air filter back plate and then I installed two 1/4-28 nut plates. Of course any type of captive nut would work (press in or braze in). Next I had to add an extra battery hold down strap because the battery needed support that the original air filter housing had supplied. There are other ways of holding the battery down besides the method I chose. To do these modifications to the tray it is best to remove the tray from the motorcycle. Once you are in this mindset it really isn't that bad of a job. The Mark IIA and Mark III battery trays are almost identical. The only difference is that the Mark IIA has an extra tab on it for the side panel attachment.



Nut plates installed with rivets. You can see that they are right next to the original captive nuts.



The arrows point to the extra hold down strap brackets on the battery tray.

The left hand side panel dzus bracket will have to be fabricated or purchased. Old Brits apparently sells a side panel bracket kit that would make the modification really easy.
http://www.oldbritts.com/13_066330b.html

Apparently the air filter attach point on the Mark IIA and III battery trays will move the lower part of the filter back a little bit. In a way that is a good thing since it would probably help when removing the air filter by adding a little extra space. Also there would be extra space between the air filter back plate and the battery which could be handy for storage.

If you decide to use the Amal Mark I's and are still using the original black cap mufflers you will probably have to experiment with the jetting. I also agree with L.A.B. about the extended ticklers preventing gas from getting on your fingers.

When I was a kid, I knew an Irishman who used to work at the Triumph factory and had raced on the IOM. I used to believe he was mad because when he talked he used to rave on about all sorts of things about racing bikes. So I never gave him much credence. He mentioned how good he thought the SU carburetors were on Triumph motors however I always thought they were rubbish and of course I knew everything about everything. A few years later I found his name in a list of IOM finishers for about 1948 - he finished about 12th on a Triumph in the Senior TT, in the era when they really did it hard. - Baldo Meli !

Thanks for all the detailed info and the photos. Really appreciate your efforts. Cheers hilbone