MkIII Mystery Cylinder

Ugh I have sympathy for novice MKIII restorers yet get an uplift from those able willing or unknowingly taking one on. I have put couple 100 miles on fully fettered MK3 and it made me feel a bit like my Jaugar XJ-6. MK3 are the only Commandos I have seen from out of state having gone across most US to get to Ozarks zoomy hwys. They do strike me as beautiful along the lines of CNW, except with more appropriate-proportional Interstate tank for large travel bag and non stop range. Still Commando was stop gap design that 1st 5yrs was the cycle to beat - then world moved on and Norton after Combat suck downs - did the best they could for rudders not into hoogilgan illegal behavior on turn pikes but still darn hard to keep up with in tights that torque rules not hi speed hp.

Anywho I have learned my pig in a poke lesson twice on cream of the crop Combats, both running and operating darn well - for a time - so its a no brainer to dig to crank and spend back out again as most efficient wise path regardless of the model.

I was hoping to tease L.A.B, one more time to view Tunnel of Love, bit forgot to type - oil - I only noticed the fella looking down at oil on her breast and the sidewalk puddle after the wild blond too off, so am impressed he found spots I had missed, as usual.

Gave myself a reality check by studying the MkIII Technical Manual again (including all the special tools involved) and searching this forum. I have decided to have someone more experienced handle the engine rebuild while I focus on other subsystems that need attention like wheel bearings, brakes and the like.

Since the bike sat for a few years, I gather that 1) the rings are stuck in the mystery cylinder and 2) the valve seats are actuating but leaking due corrosion/carbon/wear.

Drained the oil and found no appreciable sludge in the bottom of the plug nor notable metal bits.

If the 7800 indicated original miles are to be believed along with the above:

1. With this mileage is it worth upgrading the valve train (e.g., better guides, K/W valves) or just leave guides as is and replace valves as necessary? Based on input here - the cam will be replaced.

2. Is a "journey down to the crank and back" a foregone conclusion?

My goal is still to get it ridable in the 'patina' of it's current condition even if that means taking a longer path to an ultimate restoration and/or significant upgrades. Never having ridden a Commando - I want to like it before I spend like I love it.

Having done most of my own work (except milling/machining) on my other bikes this goes against my grain. Thanks for the friendly warnings...

I confess that if I found no big pieces in the sump I would get it running, see that it has oil pressure, and hope the rings and valves woke up from their slumber. If they didn't, then I'd start taking it apart.

Norton bottoms are pretty robust and about last major area to wear out in street use. Not that hard to remove head and cylinder or even to split cases BUT the infamouis Spragthrope designed primary/starter contraption would put me off bottom end permanently YET is one of the least robust areas so most common area to deal with time after time. MIKIII issues that clog forum rarely has to do with engine basics just EVERYTHING else from electrics to gear box. Likely not engine that shut yours down under 8000 miles, if speedo drive actually lasted that long to record full mileage.