75 Mk3 basket case

Joined
Apr 23, 2017
Messages
6
New to the forum, from New Orleans. I figured I'd introduce myself by posting pics of my newest project. I recently received a 1975 commando mk3 interstate. Its a complete basket case, but is also completely disassembled including the engine. Plan is to reassemble it as much as possible using original parts. once its together I'll go back and upgrade/restore certain parts. Probably start with refreshing the suspension and redoing the wheels and hubs. This is my first rebuild so I'm sure there will be a learning curve. I'll keep adding updates as I get a chance to work on it.

Parts I know I'm missing,

Front fender
gas tank
gauges
One of the brake calipers

Heres some pics!
75 Mk3 basket case

75 Mk3 basket case


Edit: resized photos
 
first update, 4/23/17

Trying to get it rolling first, just to make it easier to move around the garage. Had a bunch of trouble with the steering stem, threads were a little flattened and spend a few hours with some needle files and thread files to get it cleaned up. need to order the fork orings to get them installed.

75 Mk3 basket case


Next I tried to put the rear wheel on. I made the mistake of using a deadblow hammer to drive the axle into the hub. Couldn't pull it out and ended up having to use a 2x4 and prybar. Cleaned up the inner sleeve with a bore brush for a 12 gauge shot gun. Fits perfectly! Also took some 400 grit wet sandpaper to clean up the shaft. Still waiting for my workshop manual to come in, so only have the drawings from oldbrits.com to figure out how everything goes together. I feel like something is off because there is a gap between the sprocket and hub. Pic attached below. Also heres a pic of the other side, am I missing something? (also I'm pretty sure I put the bracket for the rear caliper on backwards.


75 Mk3 basket case



75 Mk3 basket case
 
spoiled said:
Still waiting for my workshop manual to come in, so only have the drawings from oldbrits.com to figure out how everything goes together.

There are online copies of the manual and parts book.

https://issuu.com/sealycycleservice/doc ... iiies-1975
http://britmoto.com/manuals/Manuals/850_man.pdf

The parts drawings at Andover Norton are also useful.
https://andover-norton.co.uk/en/shop-drawings/7

Use the Fig.H3(a) diagram in the manual for the rear wheel assembly because the parts book diagram isn't completely accurate, also note that some copies of the Mk3 manual say in section H4, that the rear wheel lock ring is LEFT HAND thread, which is not correct, it's RH.


spoiled said:
I feel like something is off because there is a gap between the sprocket and hub.

No, the gap is normal.
The lower shock bolt with the round head and flat under it, looks to be the right-hand bolt (which passes through, and also secures the caliper plate).
The LH lower shock bolt should have a shallow hexagon.


RH lower shock bolt
https://andover-norton.co.uk/en/shop-de ... ottom-bolt
LH
https://andover-norton.co.uk/en/shop-de ... thin-head-

The 9/16" nut on the 'dummy axle' may be the front wheel item, (the Mk3 rear nut would normally be a nylock) but in any case, that nut is fitted back to front.
There should also be a thick washer between the chain adjuster and the nut, as the shoulder (with the flats) of the dummy axle often extends through the assembly and without the washer the nut can bottom out against the shoulder before the assembly is fully tightened.


spoiled said:
also I'm pretty sure I put the bracket for the rear caliper on backwards.

Well, it isn't positioned correctly and that washer between the caliper bracket and chain adjuster does not belong there.
 
Howdy and welcome to the forum.

I suggest you immediately stop where you are at, and consider that you'll be doing double or triple work if you assemble the used parts.

AT A MINIMUM, I suggest removing, cleaning, and re-packing the wheel bearings. Also, if the isolastic rubber donut inserts are worn, dry, sagged, and/or cracked, replace them with new inserts and PTFE washers (the big brown ones).

On the brakes, pull out the pucks (a bit of a fiddle) and replace the caliper o-rings.

...and that's just the rolling chassis!

Thanx for posting photos; everyone else that reviews this section appreciates it, even if nobody else acknowledges it.
 
The wheels will get a full restore (bearings, cush drive, spokes, etc) but I want to get it roughly assembled before I start throwing too much money at it. Once I get the (rough) chassis rolling I'll start on the engine and then move on to the suspension, wheels, electronics, brakes etc. removing the wheels is easy enough that I don't mind having to take them on/off a few times.
 
Getting at the isolastics AFTER installing the engine is one heck of a chore.

(I'm just saying)
 
grandpaul said:
Getting at the isolastics AFTER installing the engine is one heck of a chore.

(I'm just saying)

I was wondering about that. Kinda overlooked it since the rear engine mount was already in place when I got the bike. But I just went and peeled back the gaiters and it was pretty rusted and nasty underneath.

Looks like these kits are cheaper than buying the parts individually.

http://www.oldbritts.com/13_067117.html
http://www.oldbritts.com/13_067116.html

These kits a good buy, or is there a different option people go with.
 
spoiled said:
Looks like these kits are cheaper than buying the parts individually.

http://www.oldbritts.com/13_067117.html
http://www.oldbritts.com/13_067116.html

As it's a Mk3, you don't need the pre-Mk3 vernier 'conversion' kits.

What you would need to refurb the Mk3 Isos. are the front and rear Iso. tubes/rubbers, PTFE washers(4) and gaiters (2 & 2).
At AN prices, all the necessary parts would cost around $97 USD (plus postage but no 20% VAT for you to pay) which is less than just the Old Britts rear kit ($127.95).

https://andover-norton.co.uk/en/shop-dr ... ad-steady-
 
spoiled said:
I was wondering about that. Kinda overlooked it since the rear engine mount was already in place when I got the bike. But I just went and peeled back the gaiters and it was pretty rusted and nasty underneath... is there a different option people go with.
Do exactly as L.A.B. has advised, the ultimate solution. You'll likely never have to mess with them again.
 
spoiled said:
New to the forum, from New Orleans. I figured I'd introduce myself by posting pics of my newest project. I recently received a 1975 commando mk3 interstate. Its a complete basket case, but is also completely disassembled including the engine.
Welcome spoiled ! It sounds like you're having fun with your rebuild. Keep on keepin' on :mrgreen:
 
L.A.B. said:
spoiled said:
Looks like these kits are cheaper than buying the parts individually.

http://www.oldbritts.com/13_067117.html
http://www.oldbritts.com/13_067116.html

As it's a Mk3, you don't need the pre-Mk3 vernier 'conversion' kits.

What you would need to refurb the Mk3 Isos. are the front and rear Iso. tubes/rubbers, PTFE washers(4) and gaiters (2 & 2).
At AN prices, all the necessary parts would cost around $97 USD (plus postage but no 20% VAT for you to pay) which is less than just the Old Britts rear kit ($127.95).

https://andover-norton.co.uk/en/shop-dr ... ad-steady-

Parts ordered! also bought the parts to refresh the front forks.
 
Started looking at some of my cases and noticed some cracking around where the gearshifter passes through the outer case. Is this something that can be/needs to be repaired?

75 Mk3 basket case


75 Mk3 basket case


75 Mk3 basket case


75 Mk3 basket case


75 Mk3 basket case
 
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