Mercury Information

Can anybody point me in the direction of parts manual information for a Norton Mercury?
I have quite a few digital factory parts manuals for pre-Commando twins and none of them seem to contain any Mercury specific information.
I did find a couple of references on the web to factory parts manuals for 62-68 twins that contain Mercury information.

One of the parts I was looking up was the Norton Mercury logo. A NOC Roadholder says the Mercury logo is located on the rear mudguard, and provides part number 25537, obtained from "the Norton Mercury parts manual."

British Only sells the logo and identifies it as a tank top sticker.

Where does the logo belong, on the tank or the rear fender? And any ideas on a source of Mercury parts information?

Stephen Hill said:

Can anybody point me in the direction of parts manual information for a Norton Mercury?
I have quite a few digital factory parts manuals for pre-Commando twins and none of them seem to contain any Mercury specific information.
I did find a couple of references on the web to factory parts manuals for 62-68 twins that contain Mercury information.

One of the parts I was looking up was the Norton Mercury logo. A NOC Roadholder says the Mercury logo is located on the rear mudguard, and provides part number 25537, obtained from "the Norton Mercury parts manual."

British Only sells the logo and identifies it as a tank top sticker.

Norton Mercury 650 Tank Top Sticker 1969-70 | BRITISH Only Austria Fahrzeughandel GmbH

www.vintage-motorcycle.com

Where does the logo belong, on the tank or the rear fender? And any ideas on a source of Mercury parts information?

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Very interesting. I've never seen that transfer. FWIW Classic Transfers says it goes on the tank
https://classictransfers.co.uk/product/norton-7642lc-64x64mm/
However I think to find a more helpful answer you will need to find a period review or advertising materials.

Stephen Hill said:

Can anybody point me in the direction of parts manual information for a Norton Mercury?
I have quite a few digital factory parts manuals for pre-Commando twins and none of them seem to contain any Mercury specific information.
I did find a couple of references on the web to factory parts manuals for 62-68 twins that contain Mercury information.

One of the parts I was looking up was the Norton Mercury logo. A NOC Roadholder says the Mercury logo is located on the rear mudguard, and provides part number 25537, obtained from "the Norton Mercury parts manual."

British Only sells the logo and identifies it as a tank top sticker.

Norton Mercury 650 Tank Top Sticker 1969-70 | BRITISH Only Austria Fahrzeughandel GmbH

www.vintage-motorcycle.com

Where does the logo belong, on the tank or the rear fender? And any ideas on a source of Mercury parts information?

Click to expand...

Here is a copy of a sales brochure for sale. No photos of the brochure so it's a bit of a mystery buy. But at this price probably worth having.

I have seen copies of that sales brochure. One of the few factory items about this model.
Here is one page: https://cybermotorcycle.com/gallery/norton-1969/Norton-1969-03.htm
This is the back page: https://www.nortonownersclub.org/sites/default/files/Mecury-650.jpg

On my highly original Mercury, the only logo was on the tank. In my media album, there is a photo showing the outline of where the sticker once was.

elefantrider said:

On my highly original Mercury, the only logo was on the tank. In my media album, there is a photo showing the outline of where the sticker once was.

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Mystery solve. Wonder what is the significance (if any) of the logo. Maybe created by the green dot people?

elefantrider, is this the logo on your tank?

Stephen Hill said:

elefantrider, is this the logo on your tank?

Norton Mercury 650 Tank Top Sticker 1969-70 | BRITISH Only Austria Fahrzeughandel GmbH

www.vintage-motorcycle.com

Click to expand...

Now that I've looked more carefully, the logo is obviously a stylized representation of the God, Mercury. For your entertainment, from Wikipedia,

The Roman god Mercury has been used to symbolize Britain's worldwide strength in the 1930s, and here the gilded figure is depicted on a mission, rapidly flying over blue-green waves. His helmet signifies power and protection, while the small wings on his heels symbolize swiftness.

Yes, that sticker looks to be the correct one. A fantastic logo btw.

I am looking for original color photographs of a Mercury when near new.

Hi elefantrider. I looked at your media page and saw a silvery patch on the tank a couple of inches back from the gas cap, off center to the right. Was that the location of the logo?
Or is it the scuffed surface on centerline about 6 inches back from the gas cap??

It is probably 4 inches back from the filler. In the photo, it looks to be to the left but it is probably really in the center of the tank. You can see what looks like an outline of the wing. By the time you need it, i can get you exact placement measurements or an outline of the position compared to the filler.

I see which "smudge" on the tank you are talking about. On centerline, about 6 inches behind the gas cap.
When you get a chance, I'd appreciate a measurement from the back edge of the filler neck to the upper edge of the wing.
Stephen

Stephen Hill said:

Can anybody point me in the direction of parts manual information for a Norton Mercury?
I have quite a few digital factory parts manuals for pre-Commando twins and none of them seem to contain any Mercury specific information.
I did find a couple of references on the web to factory parts manuals for 62-68 twins that contain Mercury information.

One of the parts I was looking up was the Norton Mercury logo. A NOC Roadholder says the Mercury logo is located on the rear mudguard, and provides part number 25537, obtained from "the Norton Mercury parts manual."

British Only sells the logo and identifies it as a tank top sticker.

Norton Mercury 650 Tank Top Sticker 1969-70 | BRITISH Only Austria Fahrzeughandel GmbH

www.vintage-motorcycle.com

Where does the logo belong, on the tank or the rear fender? And any ideas on a source of Mercury parts information?

Click to expand...

Use the 650 SS parts list, the bikes are very similar apart from the single carb on the Mercury. Of the Mercury’s sold by NVC warranty claims were virtually non existent, unlike the Commando.

Some of the Mercury engine castings were reputed to be adapted from Commando parts , Whether this is significant ?.

norton bob said:

Some of the Mercury engine castings were reputed to be adapted from Commando parts , Whether this is significant ?.

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Are they really though? Mercury head castings are similar to Commando but intake ports and valves are smaller on the Mercury head.

The Mercury gets a bad rap as a parts bin special, but I don't know how much of this is true.

I have case halves from a 70 Commando and 69 Mercury and should dig them out to compare.

elefantrider, it would be interesting to see if you see any differences in the crankcases.
Over the years I have heard that the bottom end of the Mercury engine reflected upgrades from the Commando built at the same time. But I have never heard any details about what was different.

Mercury crankcases don't have a breather on the end of the camshaft and cylinder heads are Commando castings machined to fit the 650 barrels and have the same oiling system.

What I want to know is, as Gods go, was Atlas tougher than Mercury?
I've heard that Atlas was very strong but could sometimes get the shakes when exerting himself.
Either God should be able to take on a Commando, which is a highly trained somewhat sneaky soldier, but still a mere mortal.

While certainly no expert in such matters, I've got an original Mercury motor with unsplit cases. I've removed the head and barrels to see what was wrong with it, as it was absolutely covered in oil when I got it. Looks like the head gasket blew way back when, and the motor may have been traded for a new one, or the bike parked up, sans motor, while the motor rolled around on the shop floor for 50 years. The wear on the components is minimal, but the cases are kinda beat up, with a broken fin on the head.

It seems to be a 650 SS (with a single carb) by all outward appearances, including top-oiling head, instead of the side-oiling Commando head. The cases have all the normal fittings for a chain driven distributor or magneto, and otherwise match the 650 SS cases, with no cam end breather. According to lore, they were apparently all built as a group, so I'd guess they all matched in spec, as opposed to a mix-and-match approach with a head from here, and cases from there. Although I haven't completely stripped it down and inspected it, there doesn't appear to be any difference of note between the Mercury or 650 SS motor (of which I have two examples).

Never been attracted to the 750s, so I don't have any of those, and can't offer any insight on that.