63' model 50

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Jan 5, 2005
...just joined a minute ago...I am presently restoring a Model 50 and need a little a confirmation regarding the bearing lay out on the crank..there's two rollers (RHP LRJ 1") and one ball...one roller will be on the timing side and on the drive side will be a roller ..oil ring(?)..and ball ..and seal. Is this correct?
secondly ..is there any other alternative to the gearbox main bearing which on mine is stated RLS Z 9 1 1/4" ? this seems harder to find than a flying horse shit..the 1 1/8" is very common though.
thanks for reading.
ride free.

Sorry I cant help much with the Model 50. Hopefully someone else knows.

Just wanted to welcome you to the forum. Feel free to send me photos of your project and I'll post them in the main area of the website!

I have been told,
Its the same bearing as the commando mainshaft 4th gear. carries a 1/4 size.
Any skf shop has em or brit shop. Make sure you stipulates 1 1/4 bore so they don't supply him the 1 1/8 bore.

Hope this its true, it should easy if it is so.
Model 50 bearings


It's been a while since I worked on a single. Checking parts books and repair manuals, you are correct on the sequence for the crankshaft main bearings.

The gearbox mainshaft bearing is p/n 040098. All Norton models both singles and twins from 1957 to 1975 that have the AMC gearbox use the same bearing. It can't be hard to find.
Thanks for the feedback,I managed to get the 1 1/4 main bearing for the AMC ..it's made in the US by Shatz zz series(number on the bearing is BR7754).I have fited the gearbox with upgrade of the 6203 bearing (ball) to UJ 203 (roller)...for a 350 single that gearbox should last two engines lifetime at least.
I have also installed the crank with the two rollers and one ball.All seems fine and perfect so far.
One question...does the single has a fibre washer under the valve springs like the dominator twins and roughly what thickness should it be..I am not a purist so a rough guide line will be sufficient.The fibre washer will be good for less heat on the springs in the long run.
heat insulator

The singles didn't have this from new, but you could include it. I don't think you're going to get into and coil binding issues as these are pretty low performance engines. The insulator for the Commando is too small for the spring seat and valve guide of the single, though.
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