74 Commando Carb Question

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Got a pair of new Amals for my 74. The fuel "nipples" under the bowls are not what I expected. They point out and in (like a T) but the old Amals just point out. What connects the imside ones? Just a short bit of fuel line? I hope that makes sense.
 

Time Warp

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My Mk2a had the fuel hose with the balance pipe to interconnect the float bowls.
AN seem to show that for the MK3 850 though.

pipe.jpg


The new Premiers I bought had the single barb bowl fittings which are of not much use unless you elect to build a fuel line from AN loose parts.

AN seem to show this fuel line pretty much for all pre Mk3 850 bikes which I had on the shelf so used that on the Premiers.

https://andover-norton.co.uk/en/shop-details/15631/fuel-pipe-assy-1968-73-h-style-
 

L.A.B.

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Got a pair of new Amals for my 74. The fuel "nipples" under the bowls are not what I expected. They point out and in (like a T) but the old Amals just point out. What connects the imside ones? Just a short bit of fuel line? I hope that makes sense.

The banjos originally came attached to the fuel line, either the '68-'73 'H' type line as mentioned with the single spigot banjos or the later '74-on line with the 180-degree banjos.
6ce879af2ad70f174225fded543f0c60.jpg
 
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Thanks. This thing is a 73 with a 74 engine. Has taken me forever plus covid to get my head around everything. The positive ground threw me for the biggest loop ever. I took the stock Amals off, cleaned and ordered a rebuild kit off of Ebay. Needles and seats were wrong...so I bought brand new Amals. Just trying to get them situated.
 

Time Warp

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The oddity (or not) if you were doing a restoration is AN show the H fuel line assembly (1968 - 73) for 1974 Mk2 including Mk2a and JPN but in the loose components section the line drawing is the interconnected banjo fuel line (as my bike had and correct )

You then go to the Mk3 1975 on page and it shows the interconnected fuel line as from 1974 on and the only model to use it based on their pages (excluding the loose parts pages)

(Why is that Andover Norton)

Either way if you buy Premiers you will be buying a new fuel line or using your old one as a unit. (Is one assembly better than the other vibration wise who knows)
I had considered rebuilding my original Commando fuel line assembly with new hose but it becomes harder to buy hose that does not harden quickly, the thought was to use green ARIETE hose as used on Ducati's but even on my Moto Guzzi it had lost its flexibility within a week of seeing petrol.
 

L.A.B.

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The oddity (or not) if you were doing a restoration is AN show the H fuel line assembly (1968 - 73) for 1974 Mk2 including Mk2a and JPN but in the loose components section the line drawing is the interconnected banjo fuel line (as my bike had and correct )

You then go to the Mk3 1975 on page and it shows the interconnected fuel line as from 1974 on and the only model to use it based on their pages (excluding the loose parts pages)

(Why is that Andover Norton)

Mainly due to there being no illustrated Mk2/2A parts book so the drawings are taken from the Mk1 book.

The diagram for the Mk2A exhaust etc. below, isn't all that accurate either. For instance, exhaust brackets 4 & 5 are not only drawn incorrectly but link to the wrong (Interpol) parts.
 

Time Warp

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Mainly due to there being no illustrated Mk2/2A parts book so the drawings are taken from the Mk1 book.

The diagram for the Mk2A exhaust etc. below, isn't all that accurate either. For instance, exhaust brackets 4 & 5 are not only drawn incorrectly but link to the wrong (Interpol) parts.

There is something odd with the exhaust (or seems so)
Rohan -19 had commented on a past pic that my mufflers looked to have a flat mount angle which I had given no real thought to until getting around to remounting them with that same balanced header.
Perhaps these are Black Cap headers as the angle at the exit is definitely flatter to non balanced headers I have.
The mounting plates for the isolators followed that flat angle (I had even wondered if they were Interstate parts to some degree but those headers are different afaik based off the internet)

1b.JPG


I had considered finding a muffler shop to see if they could increase that exit angle but instead fit new non balanced headers with stock type sealing rings along with new Roadster muffler mounting plates.
Even in this pic the increased angle is plain to see.

ggh.jpg
 

Mart UK

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......I had considered rebuilding my original Commando fuel line assembly with new hose but it becomes harder to buy hose that does not harden quickly, the thought was to use green ARIETE hose as used on Ducati's but even on my Moto Guzzi it had lost its flexibility within a week of seeing petrol.
Fuel line, you need to ask for line that meets SAE J30R14T1 and you'll be fine. Burlen stock it.
 
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Bit of history on this bike. Mr. Becker passed away some years ago and it was left to his son who is a very good friend of mine. He finally agreed to sell it to me last year and I now have it. I have never heard it run. It was kept in storage for many years, always inside Mr. Becker's shop.

 

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There is something odd with the exhaust (or seems so)
Rohan -19 had commented on a past pic that my mufflers looked to have a flat mount angle which I had given no real thought to until getting around to remounting them with that same balanced header.
Perhaps these are Black Cap headers as the angle at the exit is definitely flatter to non balanced headers I have.
The mounting plates for the isolators followed that flat angle (I had even wondered if they were Interstate parts to some degree but those headers are different afaik based off the internet)

View attachment 83052

I had considered finding a muffler shop to see if they could increase that exit angle but instead fit new non balanced headers with stock type sealing rings along with new Roadster muffler mounting plates.
Even in this pic the increased angle is plain to see.

View attachment 83053
The new setup seems to have something German attached to it. Not sure I like that ;-)
 

Tornado

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Can I just take the single barbs off my old Amals and replace the new dual barb ones?
With new carbs you might want to strip them dowm and fully check all tiny jets are free flowing and float height is correct. There are several reports of new sets having swarf or debris blocking a jet or two and float height being off.

Lots of tips and tricks to be found on older threads. Be sure to look at the Bushmans Guide to Amal Carb tuning, found in the technical info thread stuck to top of this forum.
 

Tornado

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Did the pics I posted yesterday show up? Ps: thanks guys.
Yes but have to jump to Drop Box to see them fully.
You can upload/post images directly in threads if you become VIP member. No ads also.
Free members must endure ads and can only link to externally hosted images.
 
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I would sir/ma'am but I am just really taking my time with my commando and sometimes a few months will go by without me even looking at it. I'm just waiting for the ever elusive get-off-my-butt bug.
 
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