Norton 850 Mk 1 1974, Service Notes, Page: 35 / 48

COMMANDO SERVICE NOTES- MK III ADDENDUM
These additional notes cover all models and the Mk III and have been put together by me from the
experiences of the club members, so are perhaps not as exhaustive or full as the previous notes written
by TRS. Some more facts on the SS camshaft have come to light from Colin Braddick who used to race
Commandos in the days of the Production racer and these have been added. Thanks this time must go to
a few club members who have managed to note any problems and a few answers, and Les Emery, John
Switzman, John Hudson and Tim R. Stevens for their help in various ways.
Al. Osborn.
COMMANDO MODIFICATION LIST Engine (COURTESY OF USNOA)
No.
Modifications
128646 New type sleeve gear and layshaft pinion tooth form.
129897 Rear wheel security bolt and MK2 type frame.
130979 'APEX' oil control ring (3 bits not 5).
132576 Fiber clutch friction plates, (not cork postage stamps).
133488 3rd gears in stronger material.
134108 First engine built in Wolverhampton works. all engines with suffix 'P' built at Plumstead
Matchless London factory.
134738 'Hylomar' (Rolls Royce) sealing compound, (they still leaked-not R.R. machining).
136618 Starter motor blanking plate fitted (for original starter to fit in old magneto recess).
140061 Plastic rocker feed pipe.
141783 1st-'71 model-non-adjustable steering head hearings.
146584 New type "S.E." oil control ring.
147730 Rear brake drums screwed and riveted.
147846 Toughened kickstart pawl.
148895 Modified inlet valve guide (for oil seals).
149670 Oil seat fitted to inlet guide.
150120 Oil pump paper gasket fitted.
151175 Increased chamfer on cam followers to increase oil drain from head.
152000 Rear drum strengthening webs.
152499 Replaceable foot rest pegs.
153150 Riveted clutch back plate.
153124 Tachometer housing gasket.
153362 Chaincase outer incorporating cap 'O' rings, not leather washers.
200000 Revised shape handlebar levers (Tomaselli). 1) shape not flat.
200000 Commando (std) cylinder head with increased inlet guide support (deleting two NM23392
heat insulating washers). Oil feed return pipes 162200 commonized for spares (17in).
200708 Cam follower locating plate modified to accommodate 1972 combat camshaft.
200976 First Combat engine (interim pistons with oil slots).
201778 Clutch plate "scrolled" groove.
202116 Master switch replaces 39565 (now 4 terminal) with associated headlamp and main
harness. Stops headlamp working when parked.
202341 Valve spring bottom seat
washer thinned to accommodate cylinder head variations (tip to 202666), stops coil
bound springs.
202666 Cylinder head amended to accommodate std NMT2073 heat insulating washers (ie
reverted to 060966 (1971), canceling above mod engine 200000).
202760 Revised front brake lever (disc-master cylinder).
203136 Front drum brake support plate introduced.
203200 Steel petrol tank (Roadster) and side covers, not GRP.
203884 Copper sealing washers introduced under rocker spindle plate bolts, and not before time.
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