1975 Norton 850 Restore

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L.A.B. said:
MS850 said:
did the 850 have the upgrade
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No unless a PO has done it.


MS850 said:
or were there problems on all models.
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Yes although this basically applies to all Commandos, the Portuguese brass-cage FAG 6203 bearing that the factory fitted to the MkIII models seems to have the highest rate of failure-but any existing standard driveside layshaft ball bearings whether brass or steel cage, should be replaced with either the NJ203E roller bearing or the Mick Hemmings FAG 6203TB P63 phenolic cage ball bearing for the sake of safety as the standard bearing has been known to fail with little or no warning which can result in the gearbox locking-up solid at speed.


http://www.doov.com/apps/nortoncompanio ... ng-upgrade
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bearing # in FAG NJ203E
 
Whilst yer in there be very critical of the 1 st gear bushing. It cracks. The sleeve gear bushes get starved of lube so check for galling.
 
Thanks, ill check bushing and end play. Apparently about 20 years ago the trans was apart and some work was done, I have to paper work from the last two owners. The repair order had gear replacement but no layshaft bearing on the parts list. Although there was a note on the RO about the bearing, so I guess it got replaced. The problem about the layshaft brg was known back then.
 
Dances with Shrapnel said:
Gear replacement? Check the main shaft and layshaft for straightness.
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will do.

thanks, mark
Roseville, ca.
 
Whats the lastest opinion on loctite on cylinder and head bolts
 
No need for Loctite on those as you will be re-torquing these up again after a good initial running -in. Exhaust nuts too.
 
Torontonian said:
No need for Loctite on those as you will be re-torquing these up again after a good initial running -in. Exhaust nuts too.
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Okay, the search response i got on this was all over the board.
All the engine ive ever rebuilt never evolved loctite on heads and cylinders ie (German, Japanese, US.), but Im now dealing with a horse of a different color and finding a few different procedures.

thanks again.

BTW I just found out the The 2016 INOA Rally "The Feather River Rally" will be held in Quincy, California.
Its a half point for day from my house.
 
Well now you have 3/4 of a year to obsess yourself with the work. Do not use Locktite on those cyl. and head bolts. You WILL be re-torquing them ,which of course would break the Loctite bond , effectively rendering any sealage/retainer glue useless. I'm impressed you got the tranny apart so quickly to check for the important layshaft bearing replacement. :D
 
Torontonian said:
Well now you have 3/4 of a year to obsess yourself with the work. Do not use Locktite on those cyl. and head bolts. You WILL be re-torquing them ,which of course would break the Loctite bond , effectively rendering any sealage/retainer glue useless. I'm impressed you got the tranny apart so quickly to check for the important layshaft bearing replacement. :D
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Yeah i get the quick thing from my wife, not sure what she's taking about, I'm thinking maybe the yard work,.......... :roll:

98% of all Harleys sold are still on the road.............. the other 2% made it home.
 
what i have found with a composition head gasket is one heat cycle and a re torque and valve reset than a 100 mile hard run to help seat rings than a re torque and valve reset and again at 500 miles.

Torontonian said:
No need for Loctite on those as you will be re-torquing these up again after a good initial running -in. Exhaust nuts too.
Click to expand...
 
bill said:
what i have found with a composition head gasket is one heat cycle and a re torque and valve reset than a 100 mile hard run to help seat rings than a re torque and valve reset and again at 500 miles.

Torontonian said:
No need for Loctite on those as you will be re-torquing these up again after a good initial running -in. Exhaust nuts too.
Click to expand...
Click to expand...

ok !
 
when you do the first heat cycle you will be surprised at just how loose the head bolts will be. that is why i do not recommend any kind of load on the first run so as to keep cylinder pressure low and not risk loosing the gasket seal.

bill said:
what i have found with a composition head gasket is one heat cycle and a re torque and valve reset than a 100 mile hard run to help seat rings than a re torque and valve reset and again at 500 miles.
Click to expand...
[/quote]

ok ![/quote]
 
I had heard about the re torque but until i did my first rebuild i thought it was just a little loose. WRONG!!! I had a few very very loose. and my damn exhaust nut i had to safety wire on. Already had holes drilled so im assuming PO had issues.
 
Safety wiring these can be deceptive. Yes for racetrack. If the nut starts backing out then it can secretly chatter at the precious expensive head threads. I use high temp copper silicone on those threads and use all my strength with the proper wrench. Honda CB 350 exh. crush rings too. Better to let it back off entirely then at least you can HEAR the exh. leak and deal with it. :wink:
 
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