Best common Fixes

Please add ones you know.

1. RTV under on front two head nuts stops oil traveling up studs that enter push rod tunnels.

2. RTV under valve cover nuts stops oil wicking up studs.

3. Grease around transmission O rings or updated seals to stop oil seepage.

4. Turn Amal air screws in a tad and richen mixture if backfiring on deceleration or erratic slow running.

5. RTV around wire exit inside primary.

6. Clean that air jet behind pilot air screw with #78 drill or guitar string

7. Upgrade tach drive with seal

I'm very uncomfortable with how many times RTV was mentioned... :mrgreen:

There no RTV inside the engine in any of these applications. Head weeping oil? RTV on bottom of the nuts as you install!

bmwbob said:

There no RTV inside the engine in any of these applications. Head weeping oil? RTV on bottom of the nuts as you install!

Click to expand...

I know. All good stuff.

Reed / one-way valve crankcase breather system

"Rose joint" top & front steadies

Tri-Spark ignition (others for nearly as much improvement)

Avon AM26 Roadmaster tires in 100/90 profile

Clutch plate stack height adjustment to improve lever pull

Sleeving original Lockheed brake master cylinders to improve lever response & feel

Chrome plated Amal replacement carb slides and needle & needle jet replacement

Locktab rings, safety wire (can involve drilling) and other aftermarket exhaust threaded nut retaining solutions

Replacement of early Commando main crank bearings with "Superblend" spec parts

Modification of early style crankcase sump "lip" and return drilling

Heinz-Kiegler (sp?) swingarm spindle (drill & clamp-on) permanent repair

Solid state voltage regulator/rectifier (Sparx, Tympanium, etc.)

That's a partial list...

Loctite :mrgreen:

Aaaaaaaaargh!
Not the dreaded Loctite (bodgers fluid).

My Upgrades, one thing I do not want to do is add up the total.

ELECTRICAL
1. Pazon Ignition
2. Duel Lead HO Coil
3. 200 watt Pedtronic regulator/rectifier
4. 180watt stator
5. Gel battery
6. Mark3 controls left/right
7. Turn indicators and flasher unit

Motor
1. Crank seal
2. Timing shaft seal
3. Recondition oil pump
4. Rebuild head valves, guides, springs
5. Compression plate
6. Hone cylinder
7. Piston set +20
8. Recondition oil tank
9. Stainless oil feed lines
10. Oil filter mounting
11. MotorMite oneway breather valve
12. Dunstal valve covers
13. Big bore exhaust
14. Mikuni 34 TM Flatside Conversion
15. SS Oil Lines

Drivetrain
1. RGM primary belt drive
2. O—ring chain conversion
3. Wheel bearings
4. Avon Roadriderr tires
5. Rebuild caliper
6. Drill/lighten rotor
7. Magura master cylinder
8. Rear shocks
9. Lansdown fork upgrade
10. Barrnet cutch
11. SS Brake line

Chassis
1. Drag bars
2. New center stand
3. Seat
4. Napoleon Bar end Mirrors
5. Grab bar
6. Speedo drive/
7. Cable
8. Teflon lined clutch cable
9. Mick Hemming rearset
10. Hursh fuel tank lining

Best common fix. Rich parents or win the lotto.

Good list or just ground up restoration :lol:

I still need to swap out the crankcase with mains. I have a late 72 set that I am machining for next winter.

Ya know, other than a few items like Dragbars and seat and the like, I read about these things everyday right here on this forum.
Common! I grant you, It's taken a couple years but still, all common fixes.

The problem with lists like this is that it's just a matter of opinion. What some folks consider an "upgrade," other folks don't. Commandos won the IOM TT without any of the "upgrades" that typically appear on lists. I doubt that any of us could do a lap at IOM at 100MPH no matter how "upgraded" the Commando is! (or even on a new 1198 Duc)

My list of useful "upgrades" is:
Brakes - Brembo MC, SS line.
Fauth front fork mod.
Trispark (NOTE - Based on the published advance curves, no e ignition will actually outperform the points/AAU if they are properly maintained.) The trispark essentially duplicates the points. So is that an "upgrade?" Well, if it's easier to maintain and it equals the point's advance curve, I'd call it an upgrade for the maint reason.
Sleeving Amals. I guess that's a good thing; mine are sleeved but these are 40 year old carbs so I don't know that it's fair to make it sound as if they were poor in the first place and that sleeving is an "upgrade." I'd call it a repair of a worn out carb. The originals on my old 750, back in the day, worked fine the whole time I owned it and I had a '71 that I sold in 78.

I guess that's it. Everything else needed - and there was PLENTY of that - was just normal replacement parts that wear out or need routine changing (brake pads, etc). To me, replacing worn parts or normal maint adjustment does not qualify as an "upgrade." And, of course, a person looking for an original commando would consider any change to the bike as a downgrade.

To me the only REAL "upgrades" that are truly an upgrade over the original performance of the bike is the front brake system (sleeving at minimum, Brembo for a truly modern stopping ability and feel) and one of the various front fork mod.

Changing a perfectly good stock part for some other part that looks cool isn't an upgrade, that's just a matter of taste, no different than one of us preferring a green bike while another prefers a red bike; or a fastback over a roadster.

Reality is they're 40 year old motorcycles and will never handle or run reliably as a modern bike! But, I would like mine to look stock, be oil tight as possible. carberate correctly with stock Amal setup, and electronics that don't leave me on the side of the road while looking stock and suspension that handles everything under the ton without feeling dangerous. I think I'm almost there. Kind of like my golf game! :roll:

mike996 said:

The problem with lists like this is that it's just a matter of opinion. What some folks consider an "upgrade," other folks don't. Commandos won the IOM TT without any of the "upgrades" that typically appear on lists. I doubt that any of us could do a lap at IOM at 100MPH no matter how "upgraded" the Commando is! (or even on a new 1198 Duc)

Click to expand...

The John Player Norton that Peter Williams won on in 1973 was a monocoque framed short stoke that probably had no stock parts whatsoever. But to be accurate, you are right. There were probably none of the "upgrades" we bring up on this list. This list is All about fettling with our farkles. It's a reaction to the fact that we have to drive around in cars that have no user servicable parts in'em.
Maybe it would be possible to make a list starting with the most useful fix ending with the most indulgent.

P.S. (F.A.R.K.L.E. -- Fancy Accessory Really Kool Likely Expensive)

Honda seal in the tach drive.

To me there is nothing like an almost bone stock Combat with
dual Amals and points ignition. If not running by one kick,
better not waste time with 2nd till key and wires and such
ckecked 1st, ahhh so light and responsive in operation
and refreshingly smooth thriller, as long as not really
winding them out and trying to keep up with moderns
in powered fast sweepers.

A few traditional tricks that over lap prior listing,
Oil pump nozzle to case rubber seal can be shoved
up tach drive instead of milled to fit Honda seals.
Use two.

For sense of the extra leverage of a sleeved master cylinder,
try melting, drilling, cutting out *All* the tiny restriction
built in by the factory rubber valve deep in m-cylinder
and install a race brake lever and SS hose.
I really wonder now if a good bit of the advantage
of sleeved cylinders is just reomoving this restriction.
I've got both a stock poked open Combat rubber hose'r
and a sleeved Combat with SS hose to compare and
arrive at my current opinion.

Can also compare the g/box sealing, to find same
amount of mild weep betwix a milled installed seal
and stock ones with a thin ribbon of foil to take up
clearance in case groove then greased surfaces installed with a
film of RTV to set up.

The single carb has less spring to work than dual Amals
but bigger single gives a tad less response till nearing
redline, then it can flow more than 32mm Amals.
Its enough difference I prefer dual Amals now for thrilling
but not insane flying.

Cut waists in the silencer rubbers for less header straining.

Fuath fork kit and mods is a delight but apparently
so is the Landdownes cartridge and similar costs.
I'll compare someday and see what's what for me.
Don't forget a fork brace as even a non rod linked

Commandos with sloppy loose swing arm and 1/4"
worn gaped isolastics can work the tights with
the best of bikes only feeling a twitch on lean
changes, till forks get to twisting-springing back,
so recommend the hassle of a fork brace.

The O in O ring chain stands for Obsolete, as so stiff.
X-ring chain much better and same lack of mess and
maintenance. Racers can keep their 520 convertions,
as eats sprockets to fast to enjoy the torque of Cdo's long.
I"ve switched back to 530 on both my Combats and my SV650.

Ford F type ATF in chain primary is nicer to clutch plates,
which still can get thick oil from the gear box shaft weep.
Dextron too but for the lack of friction additives in F type.

Rubber boots for the clock mounts,
Gatters on the forks.

Keep eye out for speedo drives, ahead of time, wear about like
tires and poor results trying to beef em up with rivets
but rivets to start on a new one will extend their function.

850 beefed swingarm is stiffer and boxed head steady
last longer than stamped plate version.
Grease zerts installed beat the snot out of the factory
constant drool to dry total loss system. Think about it : )

Can drill out front brake pivot to install matching mirror,
uses same size threads as Harley, not 10 mm Asian items.

A 2 > 1 exhaust lightens the load and adds to spunk.
But I prefer the symmetric reverse cones and sounds
unless trying to max out top end performance.

Head removal and install is only a drag d/t the
pushrods fouling the bulbous rocker arm ends.
Rockers come out pretty easy to grind them down
at least where push rods gang up. Safe to do as
no oil passage there as in lever arm and
don't need much off so push rods just slide
in and out first or 2nd try.

If tired of the kicker poking calf, grind the peg boss
and lever stop down till swings in enough out the way.

Kicker lever wobbles? Cut out clamp slot a lot wider
and though bolt it with a nut to back up.

Put in relay for headlight lo and hi beam
and not a bad idea to relay power to ignition
via kill switch path to take its long enduring resistance
out as too often stumbles the rumble from kill switch crap.

Oil tank should sit on added rubber pad not the factory stub,
or eventually fractures a leak there.

Rear brake foot lever should have the safety coil
spring added, just in that rare case of a pogo drop.

Oh yeah if shifter peg pawl spring shows some rust,
best get another to keep on bike or better to renew
before the rust creeps a crack across and left shiftless.
Paint over the inner case nuts that lie above oil
level or you know what gets em good. Maybe a blob
of grease would stay put, so I ain't trusting that.

Arrange spring tugging to tighten exhaust rings,
wire ties become loose so can still beat threads up.

Cheapest dramatic hot rod-ing of 750 is
10+:1 CR Combat + 2S+ cam with small port head
and valve, then
create a lip or ragged gasket edge intruding into flow
about 1/16" and hope your manifold is
a good mismatch to start with to give a nasty
sharp step right there to trip up the mixture.
Lighter mushroom lifters and push rod diddles
for centered stem contact.

Big bore headers and p-shooters or better
2 > 1 into long megaphone with flat plate
end baffle [supertap w/o the trap]
Put 1 3/4"-2" hole in the middle as exit nozzle.
Your call what to muffle inside with as long as
a straight though path left. Open is nutzo loud
with dulled low end,
slightly blocked exit empty insides > nice low
end response and low deep beats, hi rpm gives
blue jets projecting 6-8" with proper megaphone roar.

Try to beg steal or borrow a good points ignition
and mechanical advance. Maybe stick in a transistor
gizmo that takes the current off the points and
use real engine or gear lube on Auto Adv unit each
time of oil changes or more often.

Stick in the taller 850 2nd gears and a 20T sprocket
and have a blast trying to hang on up to 80+,
may find first reflex to throttle up thought is
hard fisted grip stiff arms planted back butt or
get left behind too suddenly.

Lighter crank is a delight with the above.

hobot

mike996 said:

The problem with lists like this is that it's just a matter of opinion. What some folks consider an "upgrade," other folks don't. Commandos won the IOM TT without any of the "upgrades" that typically appear on lists. I doubt that any of us could do a lap at IOM at 100MPH no matter how "upgraded" the Commando is! (or even on a new 1198 Duc)

Click to expand...

There wasn't much stock stuff left on a Commando racer to modify - anyone building a monocoque in their shed?

Best upgrade,
put nothing Japanese on it.
Then it will still look like a Norton & won't make me cry. :lol: :lol:

I have to laugh when I remember how we flogged the bejeezus out of these bikes back in the 70's and didn't worry about anything but gas, oil, and tires. What we didn't know, we didn't worry about. When you're 20 years old and bulletproof, oil leaks and advance curves are just not an issue.

Now that we all know better(?), shouldn't the layshaft bearing upgrade be at the top of the list?

T.C.
Remembering the hot rodder's mantra: Make it safe, make it handle, THEN make it go!

"What we didn't know, we didn't worry about."

Absolutely right...we should all be more like we were then instead of worrying about stuff like "the best oil," etc.

"anyone building a monocoque in their shed?" The Commando's that lapped the IOM at 100MPH in production class were not highly modified and they certainly weren't monocoque frames.