Atlas Cam Timing

Have you set it as per the manual and tried to run the engine?  I wouldn't think you'd normally have to check the individual timings and lift.

Get hold of the workshop manual with the cam timings, fit a degree wheel to the crank and set the pointer to TDC. Set tappet clearances to the cam timing check clearances. Turn over engine with the rocker covers off and check the valve opening and closing figures off the degree wheel to the WS figures.

Unless you have reason to believe the camshaft is incorrect and you are looking for more performance, the camshaft is normally set by assembly according to the timing marks.  It is not easily adjustable.  The manual merely says "marked on all engines". Data are listed in Bacon's Norton Twins Restoration.  I'll add a picture.

go to the "Online Library" on here, look for the "Heavy Twins Compendium" v2.2, camshaft timing is explained on page number 36/7

There should be two punch marks as on the attached. 10 pins between them.  Does yours not have them? Seems most odd if not.

In the late sixties, an old-hand engineer showed me how to set my Dommie 99 cam timing without any marks/dial gauges/degree discs :

Set the crank to TDC (not compression stroke), then, for one piston, the inlet and exhaust valves should be an equal amount off their seat, ie valves should be "rocking "  AN EQUAL AMOUNT as you rotate the crank either side of TDC. Once set to that, do the valve clearances and try it again.

( Actually, if you have valves rocking 2 or 3 degrees before TDC, the valve timing will be as near as dammit right ).

The bike flew, I've done it many times since, sometimes to get basic timing before digging the dial gauge out. The "valves rocking" method will get you within a few degrees on any " normal " engine. An easy check, even if you use it as just a rough check.

Go back to basics and give it a try......see what it says......