Mark II vs. Mark IIA
- Thread starter WEM
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Mk II and Mk II A's were produced concurrently - yours is definitely in the correct S/N range.
I will let the more knowledgeable speak to the differences. I have preconceived notions that are likely inaccurate...
I will let the more knowledgeable speak to the differences. I have preconceived notions that are likely inaccurate...
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MK2a, large plastic air box similar to MK3, black cap silencers, battery tray realigns the battery to be across the bike instead of along the length of the bike, battery side panel has no slot for toolbox and has a plastic Dzus fitting bottom right.
As the silencers could be swapped out and the air filter dumped by now the battery tray and battery side panel are the most reliable way to identify a MK2 or 2A. Any early MK2 sent to US would be a MK2 as the MK2a was for Europe but a late MK2 in the US could be a MK2a. As you are in Canada with such an early MK2 number its bound to be a plain MK2.
As the silencers could be swapped out and the air filter dumped by now the battery tray and battery side panel are the most reliable way to identify a MK2 or 2A. Any early MK2 sent to US would be a MK2 as the MK2a was for Europe but a late MK2 in the US could be a MK2a. As you are in Canada with such an early MK2 number its bound to be a plain MK2.
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Mk2
Mk2A
The Mk2 also had the higher ratio 18/23T 2nd. gear.
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The Mk2 also had the higher ratio 18/23T 2nd. gear.
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Thanks to everyone. Based on the info that has been provided, I’m pretty sure my bike is a MK2: ham can air filter, battery tray aligned with spine, tool compartment in left side panel, peashooter silencers, and no Dzus fastener in left side panel.
I’m trying to source a replacement balanced exhaust system for the MK2. The first parts drawing provided by LAB indicates that the replacements for the MK2 are actually the pipes used on the MK3. I have a couple of questions about this:
1. Will the stock 850 MK2 lockring fit over the bell mouth flare on the end of the exhaust pipes for the MK3? and
2. Will the MK3 exhaust pipes allow use of the stock MK2 peashooters?
I’m trying to source a replacement balanced exhaust system for the MK2. The first parts drawing provided by LAB indicates that the replacements for the MK2 are actually the pipes used on the MK3. I have a couple of questions about this:
1. Will the stock 850 MK2 lockring fit over the bell mouth flare on the end of the exhaust pipes for the MK3? and
2. Will the MK3 exhaust pipes allow use of the stock MK2 peashooters?
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Yes, as all 850 lockrings are the same part.
SOB broken headers!
I purchased these silencers from AN and since I have so few miles on them, I wonder if they'll send me a free replacement. It looks to me as if it broke on the weld. I'll give them a call and see what my options are. Were they under any tension at all when you fitted them?
www.accessnorton.com
No reply from Madnorton so far.
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I used MK3 pipes bought in 1990s on my MK2a, I used the spherical seats, split collets and peashooters. I used the earlier peashooter mounting plates and it all lined up. I have a set of the same pipes ready to fit made by Wassells and their bends match the old ones. Cannot confirm AN ones will have the same fit.
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If you don’t mind sharing, where did you get the MK3 pipes that you bought in the ‘90’s?
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I posted this before but I found the balanced headers on my Mk2a to have a flatter upsweep and these plates which I guess were for blackcap mufflers.
Would the blackcap equipped Mk3 not have that same muffler angle.
Same old pictures but show the noticeable difference.
Non balanced headers with mounting plates to suit the increased upsweep.
It took a reasonable amount of work (all custom fasteners) and time to get the exhaust in a supported but neutral mounting and would assume excess preload at the hanger mounts would invite muffler fractures, maybe even at the balance spigots with those headers.
Would the blackcap equipped Mk3 not have that same muffler angle.
Same old pictures but show the noticeable difference.
Non balanced headers with mounting plates to suit the increased upsweep.
It took a reasonable amount of work (all custom fasteners) and time to get the exhaust in a supported but neutral mounting and would assume excess preload at the hanger mounts would invite muffler fractures, maybe even at the balance spigots with those headers.
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I have a similar pair of adaptor plates (fitted when I bought my Mk3) to the one in your picture now replaced with peashooter plates.
Presumably, due to the increased length and weight, the black cap mounting was positioned further to the rear...
...but the pipe and silencer height and angle with peashooter plates are practically identical (the camera was positioned to avoid the flash reflection).
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I think you mean the lockring tab washers, not the lockrings.
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Based on Andover Norton links LAB provided they were different and from the MK2a parts list supplement as the numbers are different.
But oddly AN now offer the MK3 balanced pipes for the MK2 and have no pipes listed for the MK2a which may be because of the peahooter/black cap silencers.
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The (flared) Mk3 06.5256/7 exhaust pipe part numbers are the same as those listed for the Mk2A in the supplement, which is slightly odd because the Mk2A LH pipe wouldn't need the additional clearance for the Mk3 primary case. The difference in part numbers between Mk2 and Mk2A may have been due to the Mk2 pipes being flanged and the Mk2A pipes being flared.
As I've mentioned before, the Toga Mk3 balanced pipes with peashooters and peashooter brackets line up reasonably well on my Mk3 without the need to modify the brackets.
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The balanced pipes that were on my Mk2a had the flat front sealing face and split collets so perhaps not original to the bike.
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What I will do when a little more motivated is machine some locking rings same as on aftermarket 1970's Moto Guzzi nuts.
There should be enough room on the Commando, tighten the main nut then the rings are tightened against the front face of the exhaust port.
These (I shortened them) have an alloy finned cover that fits over the top but there should be enough room and access between the rose inner face and head on the Commando to do the same.
Tornado
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Another difference the II swingarm spindle should have an oil zerk on the right side cap plus a small nut on the thin cap fixing through bolt, while IIA has no facility for adding oil, as it uses permanently oil soaked fiber wads and welch end caps.
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Late mk2 can have the 2a/3 style Welch plugs and shorter spindle bushings. My 4/74 mk does.
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Mine is a very early MK2a (in first 3000 MK2/2a), as its missing the oil separator and no sign of it ever being there I think there was not an exact cutoff of the changes from MK1a to 2a with some MK1a parts being carried forward to the early MK2a's.
I remember going to Joyners to replace my old pipes and after buying their pipes with the flared ends having to go back to buy the spherical seats when I saw the difference. What I can't remember is if the pipes I took off at that time were unbalanced or balanced, unbalanced would explain the lack of spherical seats as those pipes would have flanged ends. The peashooters were there from the start of my ownership with extra holes in the blackcap brackets to account for the silencer change present too.
The MK1a pipes look to have flanged ends going into the head, if I took these off it would explain the need to get the spherical seats s.
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