Main Bearings

Yeah, I read somewhere they don't need the C3 bearings, but then I am not the expert. Seems like Norton even recommended the C3. I'm not sure what norvil was recommending, but he certainly didn't like me asking for the C3's

Dave
69S

Things run way hotter and swollen in hi rev'd Norton so on top of the crank whip bind on clearances, thermal expansion matters a lot too. C-3 is long proven way.
Closer can be run but not recommended if run hot and hard. Ken Canaga just went through this on Ms Peel crank - stiff when cases mated, turned out a bit of over plating ~0.00024" or so needed removed to spin free. He asked if had gotten C2 but assured him nope C3, so he knew to look further. So even a tight fit on crank can eat up the C3 slack. Having read lists for decade+ now, way more reports of lost joy on pushing clearances in a number of things towards the close side, as if it was a new fangled water cooled product instead of rubbery air cooled distorting wonder.

Steve, I doubt if Les would understand that, but I do.

Dave
69S