'75 850 commando rebuild questions

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I have been reading up and searching on this site for a while. I have gotten a lot on information but I now need some specific answers.

As the title says I am trying to rebuild/restore a 1975 850 commando MKIII that has sat for about 18 years. There was no prep to letting it sit, so it was ran and then just parked. It looks to be in great condition actually because it sat in a garage under a cover, so cosmetically it looks good. I have been working on it a bit over the last week. Here is what I have done so far:
I have drained all of the fluid out of it except the brake fluid and the front fork oil. I have boiled the carbs and re-assembled them. I have also gave the bike a general wash to get some of the cob webs ect. off.

I have not drained the brake fluid yet because I am looking into getting a new master cylinder and new rotors. Does anyone have recommendations for a new master cylinder and rotors?

About the oil: There is a lot left over from the bike, that has also been sitting for 18 years, is it still usable? (this includes fork oil and everything else)

I also have lead additives (again, 18 years sitting) but are they needed? I heard if they are not used then new rockers, springs, valves and seats, and even a new camshaft (rumor that 850 cams are soft?) would be needed.

I understand that the fiber washers everywhere would need to be replaced, but how about the gaskets on the manifold and bottom of the Amal carbs?

Where does everyone buy their supplies? I have not been able to locate a local place that knows anything about Nortons, so I need to know of a reputable online supplier.

I know I will need new tires, hopefully not isolastics, hopefully not an engine rebuild and master cylinder. I know this list isn't bullet proof, but do you think I am missing anything major?

Thank you for reading and responding
 

L.A.B.

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imprez55 said:
I have not drained the brake fluid yet because I am looking into getting a new master cylinder and new rotors. Does anyone have recommendations for a new master cylinder and rotors?

Do you mean there is a problem with the brakes? Or that you intend to upgrade them?

imprez55 said:
About the oil: There is a lot left over from the bike, that has also been sitting for 18 years, is it still usable? (this includes fork oil and everything else)

Oil is still quite a bit cheaper than engine parts! I would not want to use engine oil that old, personally.

imprez55 said:
I also have lead additives (again, 18 years sitting) but are they needed? I heard if they are not used then new rockers, springs, valves and seats, and even a new camshaft (rumor that 850 cams are soft?) would be needed.

In my opinion, you do not really need to use lead replacement fuel additives, but it's your choice, and I don't see how that could affect the valve gear, as lead additives are used to stop valve seat recession, but it isn't generally required for Norton engines. Some late camshafts were soft, but that was because they were never hardened correctly and nothing to do with a lack of either lead or lead replacement additives.



imprez55 said:
I understand that the fiber washers everywhere would need to be replaced, but how about the gaskets on the manifold and bottom of the Amal carbs?

If the bike has been standing as long as you say, then you can expect a few leaks, and gaskets, seals and sealing washers are cheap, so why not change them if there are signs of leakage, and the carbs will probably need them anyway?

imprez55 said:
Where does everyone buy their supplies? I have not been able to locate a local place that knows anything about Nortons, so I need to know of a reputable online supplier.

I'm sure some of our US members will be able to recommend some US suppliers?
Here is the list of Andover Norton (ANIL) worldwide parts distributors: http://www.nortonmotors.de/ANIL/Distributors.htm

imprez55 said:
I know I will need new tires, hopefully not isolastics, hopefully not an engine rebuild and master cylinder. I know this list isn't bullet proof, but do you think I am missing anything major?

I suggest you get a copy of the factory (850 Mk III) workshop manual if you have not got one yet, and the 850 Mk III parts lists are on the ANIL website: http://www.nortonmotors.de/ANIL/Norton% ... s-list.php
 
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75 commando rebuild

hi imprezz55, welcome to our "club". I have a '74 850, I had the original master cylinder sleeved and the rotor skimmed,that work fine for me.Others may advise Italian origin systems -- your choice. as for oil,as cheap as it is renew any and all lubricants engine, trans. fork, whatever.
I have no experience with lead additives,I have had a number of Brit. bikes and all ran well without lead additive -- supposed to prevent valve seat erosion -- nothing proven yet. Don't worry about valves , springs etc..As for soft camshafts,I believe that was a problem with some early '74 engines, a '75 should be fine. The Iso's. may be dry rotted -- the ones on my bike were after standing in a barn for 20 years!, tires too.
Renew ALL carb. and associated gaskets. Depending on mileage you may want to consider getting the carbs. sleeved.
I buy my Norton stuff from Frank Holmes in New Hampshire -- Franks Brit. Bike Barn -- great guy, lots of know how. Frank does not sell online, his phone no. is 603 - 323 - 8310.
I live on the east side of Cleveland, PM me if you want, maybe I can help you with your bike. Good luck. James.
 
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'75 commando rebuild

Hi imprezz55, I should also have added Stan Smith of Rocky PointCycle in Ohio, Stan is very knowledgeable and you can order online, Old Brits. in Washington state have a very good WEB site,everything for a Commando, Fred and Ella are really friendly and helpful.I hope that this helps, as I said in my first post, PM me if you want.
Good luck. James,
 

Ron L

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Welcome to the forum!

Just to add to what James and Les said, if you are looking to replace your master cylinder, I would contact Stan at Rocky Point for an exchange, sleeved front master cylinder. If you go with Brembo or Magura you will need to replace you switchgear and throttle. As James says, you can have your discs ground to remove what might be left of the chrome and they will function better.

The rear master cylinder may be pitted, but these can be rebuilt and a stainless steel body is available to replace the original. Again, Stan can help with that.

If the starter motor is still mounted, it is probably rusted after sitting that long. They never were good originally, but can be made to work with a 4 pole conversion and larger cables or one of Dave Comeau's Japanese starter conversions.
 
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L.A.B. said:
Do you mean there is a problem with the brakes? Or that you intend to upgrade them?

I mean both. The front brakes were leaky, until all the fluid drained out of them. I wanted to upgrade the stopping power of them anyways, so it was a win win. The rear still work and has no leaks so I am not sure if I want to replace that yet. It will depend on the total tab once it is running smooth.

L.A.B. said:
Oil is still quite a bit cheaper than engine parts! I would not want to use engine oil that old, personally.

Even if the oil is in the original sealed containers? Its not cheap to throw away boxes of oil either! I just want to make sure, I have a lot and don't want to waste money.

Thanks for the idea Ron L and James, I am defiantly goings to do that swap up. I will have to talk to Stan about some things like the rear master. Can Stan do the rotor skimming?

How will I know if the isolastics are dry roted without taking them apart?

Thanks a lot for the input so far, this really helped as a jump start.
 

L.A.B.

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imprez55 said:
Even if the oil is in the original sealed containers? Its not cheap to throw away boxes of oil either! I just want to make sure, I have a lot and don't want to waste money.


I must admit I wasn't sure what the shelf-life of motor oil actually was? So I hunted around on the Internet and read various opinions. Some of which say it's probably OK to use it if it has been kept in sealed containers and not subject to extremes of temperature, and to shake the container well to remix any additives that could have settled during storage.

It's your decision if you decide to use it or not. You could try contacting the actual oil manufacturer's technical department and see what they say?
 
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