1977 commando rebuild

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The photo looked like some irregularity on the inside of the crankshaft which is where i thought the metallic crap came from but it is just some of that that stuff on it
Thanks for the link Dave and the posts. You sure have done a great job and looking at your posts I realise I need to take my time to make sure I do it properly. My worry is that if mine looks as good as yours I may be too scared to take it on the road!

Jed
 
DogT said:
I'm not sure where you thing the wear is, but, no wear. Just the metallic crap that's easy to clean out. If you want to go through my 31 page rebuild go here phoenix-rises-again-t5905.html Swooshdave had a long thread on his too. There are several others around, I should make a list of them.

Dave
69S

I didn't do my engine.
 
WOW! some insignificant sludge trap residue. :P
Here's a real mans sludge trap. 60% full at aproxamately 25k miles.
From my (lesser breed) Triumph. lol
1977 commando rebuild
 
Pardon my ignorance but-
Would anyone know if flushing the bottom end out with petrol or some other solvent is advisable or would it adversely affect other components?
I thought I could plug the hole to the timing chamber and give it a petrol bath to get rid of any crap that might be in there but it seems a bit radical
Norton guys I spoke to did not think much of the idea maybe because things may dislodge and end up in other places
I was recommended to do a few quick oil changes once it was running and not use a detergent based oil

Jed
 
I doubt attempting to flush the crankcase with petrol is likely to achieve much, and won't be of any value at all as far as clearing out the crank sludge trap is concerned, and in any case, you don't really want to loosen anything inside it. The level of sludge build up inside Norton cranks shown in the previous photos is insignificant and of no real concern (when you compare them to the Triumph sludge trap).

The sludge trap is a centrifugal filter-so some build up of debris after a significant amount of mileage is to be expected. The advice you were given about using a non-detergent oil is basically unfounded in my opinion-as it's unlikely that a detergent oil would cause any problems and is probably what has been used in the engine up to now-unless you know otherwise?

If the thought of the sludge trap being blocked seriously bothers you, then there's no other way to do it, but do it properly, by splitting the cases and crankshaft and cleaning it out! :)
 
Whats in the Trap is is made up of carbon and microscopic bits of metal. Quite solid and solvent proof. If you could begin to
wear it loose, the only path for it to take is past the rod journels. They would quickly wear from it neccessitating a rebuild anyway. :cry:
 
Thank you once again for the advice
It may seem slack not splitting the case but everything is good and tight down there. Besides it's a good reason for an overhaul down the track when a rebore is needed
The head and barrels aren't back from the shop yet and will post photos once they come back and the powder coating is done

jed
 
1977 commando rebuild

1977 commando rebuild

1977 commando rebuild

1977 commando rebuild

1977 commando rebuild

1977 commando rebuild

1977 commando rebuild


So far so good
The silver powder coat with a clear finish came up great. The photos don't do it justice
The bloke quoted $360 for the job (silver was $60 extra) but charged me $100 more when I picked it up. Bit sudden but the job he did was worth it
He had a whinge about not cleaning the bits properly, in hindsight a steam clean before taking it would be better if you have the time
I did degrease and pressure clean it but admit was probably not as thorough as should be
Other club members have had their frames done but I don't think he realised the job or parts involved on a commando
The head was OK just dismantle, service & grind - the barrel honed & sandblasted they look great

Jed
 
After putting the build on the back burner for a while I finally got up a head of steam and after some thought decided to take the advice of the Norton elders and split the crankcase
Hobot threw out the challenge to be a bone-a-fide restorer by splitting the crank so thats what I did
There was about half a teaspoon of material in the sludge trap.
Since using a different type of oil to what the PO used may free the sludge causing a blockage in a journal somewhere was not worth chancing
Everything else was good.
Superblend bearings are in the big end and I am not sure if this was a later thing or introduced on the Mk3
1977 commando rebuild

1977 commando rebuild


My box was cracked badly so the older box I found needs to be modified to suit
Differences between Mk 3 box on the left and the older box on the right are -
Spigot needs to be milled on the older box to take the cross over shaft
Neutral light switch needs to be tapped in and hole chamfered on the neutral locator to take the O ring
1977 commando rebuild


Bottom end assembled
I am thinking at this point I will call the bike Murphy as it seems that is the law it abides by
1977 commando rebuild


Putting the pistons back in only having needed to replace the rings at this point because thankfully the pistons and Barrels were good
1977 commando rebuild


Barrels were put on the block without a gasket, just a good quality sealant
You should be able to see fishing line fed up through the engine to the top of the barrel which had a piece of cotton rag looped around the end
This was pulled through to clear any remnant of sealant etc which might potentially cause a blockage
1977 commando rebuild


The Darlek is almost complete!
1977 commando rebuild


Into the frame goes the powerplant
1977 commando rebuild


The SU carburettor is a curiosity and it will be interesting to see how this goes as there is not a huge amount of intel on the use of this on a bike
1977 commando rebuild


A new primary chain was no different just a couple of mm shorter. It seems crazy not to be able to adjust these but I guess they don't wear much
1977 commando rebuild


The rims will be good for a while yet and though there are a couple of blisters on them stainless spokes really cleaned up the look of the rims
1977 commando rebuild


Electrics are in and everything works!
1977 commando rebuild


Both front & rear matser cylinders needed work. The front had the half inch SS resleeve and the back seems to be taking OK with just the seal kit but it seems to be still a bit iffy. They are not meant to be that flash at the best of times so it's hard to know what is good
1977 commando rebuild
 
I finally started the Bike up and was thrilled how easily it started albeit with the ignition a little advanced
Taking it for a spin up the road confirmed why I undertook the project -AWSOME
There are still some teething issues with the SU but thats a work in progress and I'm looking forward to a long ride once the timing is right

What I can't work out is why the ignition light will not go out
The alternator is charging the battery so maybe the Boyer ignition is the culprit since the usual circuit has been bypassed
The cut out switch is disconnected due to the Boyer and will need a retro fit to put right (a rectifier or such like maybe?)
This may solve the ignition light mystery but I am unsure

If anyone can help with the electrical issues it would be great although my electrical worries pale to insignificant compared to my mates Ducati (poor bugger)

Cheers

Jed
 
Hi All,
On the Mk 111, especially, the E.S. and those sent to the Americas, have the ignition light on all the time, through the operating unit/control unit?
Mine does having been imported from U.S.A/Canada, also having the running light on permanently.
 
Thanks for that Chilli
If ignition lights stay on for the Nortons exported to Canada that would perhaps explain it
I imported the bike from the UK a couple of years ago but the compliance plate and a couple of other things indicate it was either destined for the Canadian market or was brought back to the UK from Canada at some stage eventually making the trip to Australia
It therefore does not appear to serve any purpose so I wil be tempted to disconnect it as the battery is charging and everthing else seems fine

Cheers & thanks again

Jed
 
Jed
I forgot to mention, the ignition? light goes off when you turn on the headlights, also you will have to change the control unit to an English one, and run without pilot light. According to my reading of the wiring diagram.
Cheers
 
The finished product
It goes great, the mechanic has a MK11a and a Triton (beautiful thing) he built from scratch and reckons this commando has more poke than his
That is saying something (for a stock bike) and he attributes that mostly to the carburettor. He has twin Amals on his

1977 commando rebuild

1977 commando rebuild

1977 commando rebuild

1977 commando rebuild


Jed
 
A single carb beating dual Amals? How absurd.
I only say this because I am a proponent of such thinking and a witness to said phenomena.

Oh, by the way, Nice bike.
 
That's what the mechanic said and having been around these bikes most of his life and at almost 70 I think may have some clue
The comparison is between stock bikes with modifications limited to exhaust systems
It's not like it leaves the Amals for dead but was very impressive and "might even be better"

Either way I encourage anyone able to try an SU carb to give it a go as it represents trouble free biking apart from occasionally having to add fork oil to the dashpot

Jed

I used to have an open mind but my brains kept falling out
 
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