Low mileage, semi-basket build thread

[fatmatt]

Howdy, all! I recently purchased a low mileage 74 Commando w/ a basket case motor. I have extensive experience in resurrecting old SOHC Hondas and have finally acquired my dream bike, a 74 850 Norton. The bike only has 5,400 miles on it but according to the PO it was assembled at the factory missing a shim on the crankshaft. He claimed to measure .065" of lateral play while the manual specd .018". In conversation w/ other Norton specialists he identified the issue and tore the motor down to fix it. That is as far as he got and after many years of sitting he sold it on to me. I am now wondering whether to attempt the rebuild myself or source it out to a professional. I plan to keep the bike forever and ride it hard on a regular basis. I have never been deeper than a valve cover gasket in any other engine but I am a relatively patient person, I have the factory workshop manual and I'd love to do it myself to gain a deeper understanding of my machine. Any opinions on which way I should go?

 

[Rohan]

Re: New Norton owner, 74 850, Help!

Welcome here.

Did the PO think this actually caused a problem, or may just cause a problem.
It has previously been discussed here that the factory didn't really set the crank endfloat, just punched them out since they were likely to be in the general ballpark - and didn't seem to cause any problems.
Maybe someone has better insights into this ?

It doesn't really pay to try to solve all the theoretical problems that may afflict british motorcycles - just ride and enjoy them ?!
There are a number of upgrades that can be applied though, depending on your wallet and inclinations.
Have fun....

 

[fatmatt]

Re: New Norton owner, 74 850, Help!

He thought he felt a "rod knock" while riding and so tore it down to inspect it. I have a friend w/ a similar bike and the same issue and he says his crankshaft was floating enough to shave metal off of the adjacent cover. Whether it was a real or imagined issue on my bike, I'm still faced w/ the issue of a disassembled motor, i.e crankshaft, pistons, etc in a box.

 

[Matt Spencer]

Re: New Norton owner, 74 850, Help!

Some think 7 thou end floats ideal . with the barreled rollers .

Hardest bits going to be learning how to work on it without getting dirt under your fingernails . :wink:

noise if gnarly even amplitude may be a rod end , or piston slap . BUT the CAM could well be knackered , and may get a kadang - interval - kadang - type sound not disimilar .
So its checking for metalic debri , clearing oilways , etc . Check Oil Pumps A1 .

Setting the Cam set up corrects a good exercise . A precision valve train will see it running smoothly & efficently . At that milage wear otherwise is likely minimal , so a bore hone maybe
and inspection of all mateing surfaces & bearings should see you under way .

pretty well mandatory to fit a cartrige filter set up , too .

Of Course lots of pictures , under a strong light , of any concerns will get multitudeonous answers from all comers .

 

[Rohan]

Re: New Norton owner, 74 850, Help!

I have a friend w/ a similar bike and the same issue and he says his crankshaft was floating enough to shave metal off of the adjacent cover. .

We are grappling to imagine where this cover might be that would be affected ?
Anyone ?
Not a commonly discussed problem, that we can recall here anyway ?
I could be corrected on this of course.

Can you just assemble it back together and try it.
A shop would charge a fair amount to do this for you, gets expensive quite quickly.
Is it said to be all there. ?
They are not complicated or fussy to put together - just be methodical, and follow the book.

 

[Rohan]

Re: New Norton owner, 74 850, Help!

Some think 7 thou end floats ideal . with the barreled rollers .

Is there any whys or wherefores on why this is so though.
The factory is said to have asembled them with all sorts of endfloats, with seemingly no undesireable effects ?

 

[fatmatt]

Re: New Norton owner, 74 850, Help!

I'm not sure but I believe it was the timing cover that was being abraded on my friends bike. The PO claims all the parts are there and he provided an impressively heavy bin of greasy old stuff so I'm inclined to believe him. He did actually seem like a reasonably intelligent, thoughtful fellow and I assume it is, in fact, all there. I've yet to conduct an inventory. My concern in attempting the rebuild myself is that their may be special tools and/or professional insight necessary to complete it properly. I've skimmed the factory manual and am leaning towards tackling it myself. I bought an engine stand on ebay last night. I don't mind throwing a bit of money at it to have it done by an expert but if y'all think it's worth trying myself I'm game for it.

 

[Matt Spencer]

Re: New Norton owner, 74 850, Help!

If the thing starts walking round , it could come out through the side . The set up Pre Superblund was a nother cup of tea . If 6 to 10 was recommended , 6 was 4 less than ten end float .
The issue is NOT to have side loading in the bearings . though a pre load might allow for expansion , if some cared to check it hot .Presumeably could gall from cold . Then thered be
forign particles circulateing .

 

[Rohan]

Re: New Norton owner, 74 850, Help!

I've yet to conduct an inventory. My concern in attempting the rebuild myself is that their may be special tools and/or professional insight necessary to complete it properly. I've skimmed the factory manual and am leaning towards tackling it myself. I bought an engine stand on ebay last night. I don't mind throwing a bit of money at it to have it done by an expert but if y'all think it's worth trying myself I'm game for it.

You probably need to have a trial assembly of it, to see whats there and what condition everything is in.
Ask here, and someone will know, if any uncertain or unclear steps - we all learn from this process.
If you then take it to a shop, they'll appreciate not having to do this, and charge you (considerably) less for it.
You probably need to say where you are, so folks can maybe suggest somewhere to do this.
Be warned that most shops will want to do a full-blown rebuild = $$$
Try it yourself, and see where that goes.
You'll need to assess how clean the engine is inside as to whether the crank needs to be inspected inside, in case the crank sludge trap requires cleaning.
Getting the crank back together and running true is barely an owner operation - although some here have done it ?


I would not have thought it possible for the crank to be that far over, or to be able to get that far over, if all major components are there and assembled ??
We can but learn of these things though.

 

[mike996]

Re: New Norton owner, 74 850, Help!

If you have the shop manual and are reasonably mechanically-mnded, you can do this all yourself if you feel inclined. None of it is difficult technically though you may need a few special tools depending on what you have in your garage. But the ones you really need are not particularly expensive and some of them can be made easily enough by "adjusting" a standard tool - narrowing wrench heads with a grinder, stuff like that. To me the most useful Norton tool is the clutch tool but even that can be made though IMO it's well worth purchasing the real thing.

 

[concours]

Re: New Norton owner, 74 850, Help!

Hi Matt, welcome. The "shim left out" story remains to be validated. There may be much more at play here. (All repairable) but go slow, and be SURE of the information used. It's an expensive first project, with expensive consequences if it fails. Please tell us more about your skill set, wrenching accomplishments, age (EFI/HEI, or carb/points) , we can better aim the advice. That said, enjoy the ride, best of luck!

 

[concours]

Re: New Norton owner, 74 850, Help!

I'm not sure but I believe it was the timing cover that was being abraded on my friends bike. The PO claims all the parts are there and he provided an impressively heavy bin of greasy old stuff so I'm inclined to believe him. He did actually seem like a reasonably intelligent, thoughtful fellow and I assume it is, in fact, all there. I've yet to conduct an inventory. My concern in attempting the rebuild myself is that their may be special tools and/or professional insight necessary to complete it properly. I've skimmed the factory manual and am leaning towards tackling it myself. I bought an engine stand on ebay last night. I don't mind throwing a bit of money at it to have it done by an expert but if y'all think it's worth trying myself I'm game for it.

www.oldbritts.com parts drawings will allow you to take inventory.

 

[DogT]

Re: New Norton owner, 74 850, Help!

It's the dis-assembly that takes all the special tools. Don't need much to put it back together other than all the parts in good shape, good set of tools including a few WW and patience. May as well set the crank float while it's apart, not a big problem, just a few shims. Old Brits has a complete set of motor assembly instructions if I remember right. If I can put one together, you can. You may need to check some of the obvious things, piston size, correct ring gap, cylinder bore size/oval-ness. Might as well do it right. I assume the crank has not been dis-assembled, but you'll want to check all the torque settings, which is in the OB site.

Read over the OB instructions and see what you think. The head is not apart? If you don't need to work on the head, that's the biggest item. Depending on where you are, you may be able to get some local help, which wouldn't hurt. Make a build thread out of this, I'd like to watch.

You may want to think about some improvements while it's apart, I'm thinking about ludwig's cam oil trough, the comnoz timing chain adjuster. I think your bike is good breather wise but others will know.

You need to think about EI if it doesn't have that.

Dave
69S

 

[fatmatt]

Re: New Norton owner, 74 850, Help!

Hi Matt, welcome. The "shim left out" story remains to be validated. There may be much more at play here. (All repairable) but go slow, and be SURE of the information used. It's an expensive first project, with expensive consequences if it fails. Please tell us more about your skill set, wrenching accomplishments, age (EFI/HEI, or carb/points) , we can better aim the advice. That said, enjoy the ride, best of luck!

I'm 41, been a professional bicycle mechanic most of my life, restored a few 1970s Honda cb400s, 750s and such, keep a minor fleet of old VWs running, like sunsets and long walks on the beach, and live in Pacifica, Ca in the San Francisco Bay Area. I am just down the way from Kibblewhite Precision Machining, they do incredible work but charge the proverbial arm and leg.

I believe I'll start w/ the aforementioned mock-up and take it from there. I'll keep y'all posted. Thanks again for all the excellent information and advice. I'm really glad I found this forum.

 

[DogT]

Re: New Norton owner, 74 850, Help!

I think T95 is in your area, Pacifica. Maybe you could shoot him an email or PM.

Sounds like we're going to have your weather here this week, it's about time, we get so little of it. High of 80 today and humidity was only in the 40's. It's usually 80 or more and 80%.

Dave
69S

 

[rx7171]

Re: New Norton owner, 74 850, Help!

I'm not sure but I believe it was the timing cover that was being abraded on my friends bike. The PO claims all the parts are there and he provided an impressively heavy bin of greasy old stuff so I'm inclined to believe him. He did actually seem like a reasonably intelligent, thoughtful fellow and I assume it is, in fact, all there. I've yet to conduct an inventory. My concern in attempting the rebuild myself is that their may be special tools and/or professional insight necessary to complete it properly. I've skimmed the factory manual and am leaning towards tackling it myself. I bought an engine stand on ebay last night. I don't mind throwing a bit of money at it to have it done by an expert but if y'all think it's worth trying myself I'm game for it.

I managed a full rebuild of my bike and I'm an Architect who's previous experience was rebuilding a basket case Indian with my brother while I was in high school a long time ago.
Like others have said the bike is actually pretty simple, and by following the shop manual and looking at OldBritts how-to articles plus following the order of parts assembly shown in the Parts catalog you can do it. There are a handful of special tools needed and available from parts vendors, and I've even rented a couple of the more expensive ones from OldBritts.
However photograph in detail every step of disassembly for reference when reassembling since order of shims etc can be baffling when done months after disassembly. This is also very useful for wiring connections. Get close enough to identify wire colors.
Last but not least when you have a head scratcher take good photos of the item in question and post the problem on this site.
The amount of knowledge here is truly amazing and it is gladly shared with anyone trying to bring a Commando back to life.
You may have already done so but if not browse the archive threads since there are so many that cover many aspects of the bike, including upgrades of ignition, carbs, brakes, gearbox layshaft bearing etc.

 

[rvich]

Re: New Norton owner, 74 850, Help!

Mick Hemmings put out a DVD on rebuilding the engine and another on the gearbox. Beg, borrow, steal, or if you have to buy one. Spend some time watching it and it will probably ease any fears of tearing into one of these motors. The DVD goes for 45 dollars I think, which in the long haul isn't much to spend for the amount of information involved.

Russ

 

[DogT]

Re: New Norton owner, 74 850, Help!

Yes, the dvd convinced me to get into my engine and gearbox.

 

[Bernhard]

Re: New Norton owner, 74 850, Help!

I'm not sure but I believe it was the timing cover that was being abraded on my friends bike. The PO claims all the parts are there and he provided an impressively heavy bin of greasy old stuff so I'm inclined to believe him. He did actually seem like a reasonably intelligent, thoughtful fellow and I assume it is, in fact, all there. I've yet to conduct an inventory. My concern in attempting the rebuild myself is that their may be special tools and/or professional insight necessary to complete it properly. I've skimmed the factory manual and am leaning towards tackling it myself. I bought an engine stand on ebay last night. I don't mind throwing a bit of money at it to have it done by an expert but if y'all think it's worth trying myself I'm game for it.

http://www.oldbritts.com parts drawings will allow you to take inventory.

see;
http://www.oldbritts.com/11_067569.html

 

[DogT]

Re: New Norton owner, 74 850, Help!

Yes, the outer bearing race shims are much easier to use than the inner race shims. You really don't want to be pulling off that inner race from the crankshaft any more than you have to.