520 "O" Ring Chain

Derek, three reasons for taking the all the stock off the out side. I have seen many Nortons being repaired and modifiyed in the last 15 years and something that almost all the older ones have is a chain guard kissed by a chain always on the outward side. Then the inside of the inter primary cover also is found kissed by the chain. And last of the reasoning when you set an Atlas sprocket and a Commando sprocket on a surface plate you will see that all the extra metal is on the outward side. All this chain rubbing has to do with owners bad habbits. replacment chains too wide, rear wheel way out of straight, trans way out of straight, inproperly shimmed inter primary cover, wrong bolt used on the chain guard mount, and add many other reasons. But the damage is alwas on the outward side so it just seems right to take it off there and make some slack. norbsa

wheel alignment

Interesting...
None of the ones I've done have rubbed the chain gaurd, but you are definitely right about the chain running closer to the outside of the gaurd. Makes the job easier, only machining one side of the sprocket. I was a little concerned about sprocket alignment, but you are also correct about doing alot of damage by not aligning the wheels.
The transmission sprocket HAS to be machined on both sides. I have actually been considering machining more from the inside due to the chain running within 0.020" of the transmission case, but I have not had one rub.
Cheers,

Positive Ground/Autometer

You can purchase a magic box from JC Whitney that will convert positive to negative. I had to purchase one after I installed an electronic oil pressure gauge and found out it wouldn't work on positive ground. The box is rather expensive (IIRC <> $80) but it works great. You need to check how much current is required for the Autometer gauges because it is limited in what it can supply. I don't recall how much, I think maybe <> 3 amps? I'd like to do that Autometer thing myself. Cool!

dwardo
If I remember right and thats asking a lot, autometer says to use a 3 amp fuse BUT that is NOT the draw. I have not checked what it is.

bill

Just picking up an old thread.....
Have any of you UK guys done this conversion? My current year old chain is badly stretched after 3200 miles, despite lots of PJ1 and other lubes.
I'm hesitant to take a new rear drum to any machine shop without knowing what I really need done. I guess they can't just mill .125" off the outer, it has to be a profile with a taper? Am I correct? Maybe we could persude RGM to take this on as a mod?
Any input would be welcome. Thanks.