1977 commando rebuild

The ID shows the 1977 commando as it was when I bought it, Although pretty tidy it was showing the stresses of time
It seems to have been reasonably well cared for and I will post pictures of stages along the way of the rebuild
This will take a while but I hope some viewers may get some benefit as I have already from using this site
Hopefully the bile will be better from the process

Very cool. Can't wait to see more pictures.

Thanks for that Matt looks like you got some pretty cool bikes
I saw your footnote before seeing the message and was a little put out at first (need to keep my glasses on hand)
By the way I live in the hills and I am a grumpy old man so now I just have to hope I can fix a real motorcycle

Cheers

Jed

Glad I did not try to start the bike as there was a broken ring. The bores look OK
Almost on the way back!

Mine will not be a "glam" restore but as close to original as possible in order to qualify for the prize so it may be a bit boring to some but will be as close to as it was in 1977

Cheers Jed

I'll be following your rebuild. I kind of like the originality of the bikes, not to object to someone that wants to go in another direction, just my preference. I tried to rebuild mine with only improvements that don't detract from the original style. Go for it.

Dave
69S

Cool!

This will be a great thread

The Norton community thanks you taking on this project and bringing one of our brothers back to life!

Thanks for the kind words and support. I will do my best not to disappoint though I don't have as much time to spend on it as I would like
I have decided to powder coat the frame in any colour I like as long as it's black and am sussing out the best place to take it
Cheers

Jed

Make sure you check out the article in Old Brits about powder coating. See if the guy doing the work will let you mask off the areas needed. He should have all kinds of plastic stick on circles to mask the motor mount areas and other places. He should also have sheets you can cut to any size to place over the area around where the swing arm mounts on the cradle, the sprockets for the rear, etc. Forget the nuts/bolts/washers OB recommends. I even masked off the gearbox mounting areas and the battery box and chassis braces where the iso's mount. Mask a couple of places around the coil mounts so you can get a good ground to the chassis. You don't want to be trying to cut the coating off later. When you start putting things together, just paint the uncovered areas with some rustolium enamel. Can't even see it, especially if it's black. I used "chrome" on the tree parts and the fender bridge to sort of match the silver that was on them. Try to get everything blasted and coated in one process, cheaper that way.

Dave
69S

Thanks for the info on the powder coating Dave
I must admit the powder coating process is a bit daunting especially since the frame is in pretty good shape and chips and scratches are harder to deal with
I wonder if getting the main part of the frame and swinging arm powder coated and the rest good quality paint would be too much of a mismatch?

The barrel is being honed sandblasted and painted at a reputable machine shop and the bottom end seems tight and OK so I don't think there is any need to go further so hopefully I have turned the corner. Just the gearbox to go but there should be no dramas there

Another question
Does anyone know what the optimum slack in the timing chain should be?
The manual says 4.8mm up and down. Does this mean 9.6mm overall or 4.8mm overall?

Cheers & best regards

Jed

Hey Jed,

Good to see another bike being given he once over.

Do you know what the sludge trap is ?, the one in the centre of the crank ( assuming the 850's also have it ), this really deserves a clean if you are pulling the engine apart.

Cheers

Josh Cox
Cairns
0428 241 105

Hi mate

Not sure what the sludge trap is or where it might be found
My motor has a really large plug in the bottom of the crank case which has a steel mesh gauze filter in it which may do the same thing

That sucker took some undoing I can tell you!

Jed

Cam chain must be checked over a few rotations to set most tense position of chain for ~3/8" slack, Ie: the rest of the chain positions checked should have more slack than this tightest 3/8" play section - both up and down, so total up/dn play at tightest point gives double 3/8" or what ever that is in silly mm's.

Ugh there is an ancient accepted British Iron Motto I've had drummed into my head by the Triumph crowd
Clean The Sludge Trap! Its the center hollows of the crank shaft that the spin slings heavy particles to its 'low' spots instead of scouring a path through the rod shells/crank journals. But this is a Norton not a lesser breed so very unusual to find enough in them to bother with and what's in there is cooked into a hydrocarbon metal dust cake that is both stable and immune to solvents but which may remove enough hydrocarbon bonding to let chunks break loose with thermal expansion of crank surface. Your can't consider your self a full Norton mechanic restorer w/o parting the crank but I don't think a Norton crank can clog up like lessor breeds, just cuts a flow channel though sludge to the rod oil vents by the pump and spin pressure.

I wonder if I'd be up to the advanced complexity of such a recent '77 model compared to my ole '72's.
Back in '99 I didn't even know where the ignition was located and the manual looked too complex to study much, ugh.

Jed said:

The manual says 4.8mm up and down. Does this mean 9.6mm overall or 4.8mm overall?

Click to expand...

4.8mm (3/16") overall (not 3/8" :shock: )

Here are some photos:

You'll probably me amazed at the amount of crap in there. ( all my photos are here: http://s113.photobucket.com/albums/n229 ... ?start=all )






The rivet counters ( Hi guys !!! ) will recommend changing all the bolts etc etc, I was advised by someone far more experienced than me that it is not required, definately check all threads and nuts, make sure you use plenty of oil on the bolts before using the torque wrench.

Thanks Josh

Any Idea what kind of mileage was on that motor?

The gauze filter in the bottom of my case was virtually free of that gunk but that may not mean much

Jed

Thanks Lab for the info on the timing chain

You too hobot but If something aint broke why fix it
The bike had 32000 miles on the clock, the bore/pistons were good and if I were you I would be checking the tension of my timing chain
Metric or imperial if the info is wrong it aint worth poop!

While I have pulled motors apart including the crankcase this is my first Norton so I don't consider myself a restorer but an enthusiast

Cheers and stay right side up

Jed

Less than a 1000 miles.

The last bike i restored was a BSA, it has a different type of sludge trap, it was entirely blocked, infact i had to blow the crap out with an oxy accetaline.

Here's what mine look like at 13K miles and no filter.



Dave
69S

Thanks for the heads up on that crap residue hide hole
Looks like another topic for the knowledgable ones at our next classic bike meeting
Problem is after seeing that I will be wondering if I should be pulling my motor down after another 13K miles
By the way Dog T is that wear in the centre hole where the sludge came from or is it just the photo?
It would be great if you could post more info on your builds as they progress

Cheers Jed

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