My First Commando...

Well one way was uphill, across a busy road...the other way was none of that...guess which!

3000 rpms means over 50 mph in 4th and that just too fast for many situations so obnoxious vibes or risking too fast for safety to reach isolation. Down shifting to 3rd or lower to stay above isolation rpm means ya are chewing up dry/hot sleeve bushes which only ever get some drool down lube when in 4th. Original Commandos isolated about 1800 as Frankdamp Norton tester verifies so put that in your pipes and remember hobot beveling bragging suggestion - if feeling engine vibes after 2000-ish battery charging rpm, instead of hand of God turbo fan thrust in short shifting Harley like ease. Make what ever rationales ya need to accept 3000 isolation but that's piss poor ignorance to hobot's 2 flying carpets. Ive ridden 5 others Commandos some builders shops farm out to restore, none felt as smooth as my corruptions. Hope to snag a cheap smart phone with vibe application to pass around for pecking order objective data.

I say buy new front cushions and bevel to narrow flat rim then put-add the 2 old big front cushions in rear iso stack un-beveled. BTW a breast support radius rod link or swash plates eliminates most sense of vibes from road texture and wind gusts so with a rod link head steady can give surprising deeper level of isolation for sane use. Only a rump link allows the real handling potential to emerge yet only 4 people tired it so far but only 2 tested to race level joys one being the late great Bob Patton.

hobot said:

I say buy new front cushions and bevel to narrow flat rim then put-add the 2 old big front cushions in rear iso stack un-beveled. BTW a breast support radius rod link or swash plates eliminates most sense of vibes from road texture and wind gusts so with a rod link head steady can give surprising deeper level of isolation for sane use. Only a rump link allows the real handling potential to emerge yet only 4 people tired it so far but only 2 tested to race level joys one being the late great Bob Patton.

Click to expand...

there used to be easy to find fab detailed pix of the "rump link", including 8 pix in this post alone, all gone now
https://www.accessnorton.com/NortonCommando/watts-like-triple-helm-linkage-on-ms-peel.6189/

this is all i can find now, the rump link just below the oil filter
https://www.accessnorton.com/NortonCommando/pictures-of-rod-linkages.15327/#post-219538

What's confusing about saying how to stay safe sound legal in traffic w/o jarring parts and nerves. 3000 level isolation is a serious faulty condition to me. I've done brutal methods to get alignment clearances to assist lift off ~2000ish, which is the main attraction/addiction to Cdo's for me, ie: cycle disappears from senses leaving only smooth turbo fan thrust sensation and road texture/wind blasts glee. After couple decades of seeing the isolastic cushions elastic deformation tests seeming always increasing and remembering Norton scab together stop gap experiments almost failing til they cut the cushions in 1/2 the 3rd time, EUREKA, 1800ish isolation. Of course that was likely d/t still existing Rothschild India rubber tree plantations supply the natives finally took back. A fully fettered factory Cdo should feel like a flying carpet with only the fancy fringe flapping in the breeze while a tri-linked tame Cdo feels like the fringe trimmed for complete uncannty disappearing act after about 30 mph in 4th.

I still tingle and twitch a bit from you pointing me out to Kelly that started his flat track winner up w/o warning with me unarmored on it then sending me off into dim lit inner field solid surface hook up G Spike traction over soft loose race tract - saying ya know how to ride a Combat, Go for IT! The open exhausts vibed more than Cdo before isolation so nullified isolation about time my cap blew off then snicked 2nd lifting front 40's degree's before crying uncle, a few times with people and ATV's crossing path between lumpy brushy clumps and dried/rutted mud flats. Alas my Ms Peel would flat run out from under me leaving barely hanging on snagged on tail light/tag in similar surfaces on snaps w/o wheelie. Can have smooth cake and handling too before ya die.

Right from the factory they all had a vibey area in that 2300-2800 rpm range. A good friend did all of the predelivery service and test rides for the Norton distributor in Vancouver, British Motorcycles Ltd 1969-1974. He figures he got first ride on several hundred new Commandos.
That zone was common to all.
The Norton Riders handbook says if you don't like it, shift down.Thats why they included a gearbox. It won't break or dry out, it's full of oil that splashes everywhere.
2 k in top, on the other hand is just asking for detonation. Who rides like that? Not much is worse for an engine than making it lug.

Glen

The rump rod photo above is past Ms Peel as 2nd example after late Bob Pattons first one. Bob literally did the math on loads and best placement which followed. I was flabbergasted by Peel disappearing act ~2000 as unexpected benefit form world wide advisors. My factory Trixie Combat came to me only able to isolate over 2500 but got to 2200ish by tweaking front mount tabs and bending head steady mount plus beveled front cushiions. Commando developers got it below 2000 but likely Norton changed cushions as couldn't/wouldn't pay original suppliers. If anyone ever tries beveling the front cushions please let us know the sensations or lack there of. Most appealing thing I found with rod links was how much each one helped isolation, the front being most noticed, then rump then head steady. Going slow in smoothly 4th is a delight which also avoids the wear of running in lower gears. There are smart phone apps that record vibration so hope to get those reports someday.

So I'm still making some fixes to what found on first rolling test. Front brake went very soft, and could not generate significant stopping force...I'd say even less than rear foot drum brake. Something had changed BC it was a lot firmer just as I started out and had been so in the weeks prior in garage. Did yet another few complete fluid exchanges using reverse bleed with syringe. Not much change...very squishy. Tried filing a bit more material off the lever end where it comes to rest on mounting casing under no load. Not seeing any fluid disturbance in reservoir during lever pull in like it's supposed to do. I do get this if lever removed and I push piston in by a finger.
In frustration, I started rapidly pulling lever hard in, then letting it flick rapidly back out...50-60 times and I saw a very tiny air bubble come up out the smaller reservoir hole. A few more minutes and another and another. Lever firmed up substantially from earlier...but still a bit squishier than I'd like. This is after many nights with lever held in, bars at full left lock etc. So seems there are still spaces where air can live. Got to tied in again now and will assess again tomorrow.

Are you removing the cap and bellows when you leave it overnight? That bypass port is so tiny, I had trouble getting air through it even with the primary cup well back from the port (doing this all dry, not installed). Then I noticed that if I put the bellows in, it was much harder, and if I screwed on the cap even just partially, it was almost impossible, even with the vent in the cap cleared out.
When my time for install comes, I'll be pulling out the heat gun, too, try to get those bubbles loose and up.

No I've had the cap on with the bellows in place. Kinda weird to need to leave it off...absorbing moisture all the time! Then you'll need to exchange the fluid once more I guess.
In theory it should not prevent trapped bubble escape, as you can watch a trapped bubble moving vertically along a completely sealed clear tube as the fluid can pass slowly around the bubble.
Initially I thought it strange the common knowledge says to hold lever pulled in over night....this closes off the line from the reservoir entirely. But it does place system under some build up of pressure, making trapped air bubbles more compressed/smaller, thus more able to flow vertically. Then if they've made it to the seal cup, releasing the lever should allow them out the hole if they are sitting nearby.
If my system is still questionable tomorrow, will try taking it all off the bike while leaving all connections in place, then working the MC/Caliper in different orientations on the bench.

What I've run into was a layer of almost microscopic bubbles adhering to the hose texture insides. In that case took a while to figure out as good hard braking a few times in a row, like down Mt. twisty then fading/squishy suddenly scary NO Brake. May want to use a vibrator from bottom caliper up along hose to bars with lever tied back. Your are not moisture contaminating brake fluid only exposed a day or two but adding hot air/hair dyer 'severely' bottom to top ain't a bad idea as the micro bubbles expansion would merge many together for size to rise and pop at the top. Once you got firm cold brake grip definitely pick a place to pull down and speed up hard as can half dozen times to be sure of air and moisture elimination. I've various brake failure bikes to cages and each time it was perfect then next instant Completely Gone. I've never had a m/c that did not jet fluid a few feet up all over paint with anything but a few seconds long squease. This seems the most concerning symptom/sign as even when I did not have all the air out I still had to be careful with rags all around as tricky to move slow enough not to jet in the face.

It took me about a decade of hand holding like you to to eventually not need the manual, which has a number of serious errors in it plus impractical procedures. I think Commando/Nortons and Spragthrops may be the only breeds that needed the C curved end wrench to access a few vital hi trq fasteners. Likely the 1920's Whippet is most similar of kennel mates then Evolution era Harleys. Strangely of all cycles ever was or to come, only late 850 Commandos and Spragthrop Company are associated with "sprag" so likely they stole the worst parts from cheap skate shoddy Norton too.

https://encrypted-tbn0.gstatic.com/...nx23AuLjUNqlin-niDje91RJyJu_PIFDjb2xQlpcuB2vg

http://cybermotorcycle.com/euro/wikig/Spagthorpe-Motorcycle-Co.html
http://cybermotorcycle.com/archives/spagthorpe/index.html

Okay, I just realized I was not being clear at all, my fault.
You're right, there is no point in leaving the cap off overnight, the system is sealed off. I was referring to the moments after (or just before) letting the lever go, in the morning.
In principle, there will be a nice fat bubble right up against the primary cup, waiting to be released into the reservoir through the bypass port as you uncover it by releasing the lever. What's more likely found are a bunch of tiny bubbles that have not aggregated. My thought is that they are more likely to escape if the path to atmosphere is not restricted by the bellows and cap.

Ugh, confusing pressure gradients with bouncy gradients so should not matter with seal and cap on if not pressurized over 1 BAR which would compress bubbles to adhere smaller/tighter but ain't at home at rest so not the physics working in air evacuation. Bubbles still rise in 'hi pressure' fluids unless compressed so tiny they can't. I've exhaled big bubbles 3 x's atmosphere 170 ft deep in Blue Hole for example. Nitrogen Narcosis is rather pleasant. Human body and Commandos are complexly simple mysteries. Commandos constantly test my wits and will power and half the time solve by accident w/o ever knowing why, similar to people quirks. Why oh why did you pick this frustrating hobby horse?

Front brake seems much healthier today. As a test, pulled off cap/bellows before releasing of lever from overnight settle. Many flicks of lever to rest position from full/hard in...did not see any hint of a bubble at the small hole.

Will see if it self softens in a few days like last time.

Brake seems to be holding.
Had carb off for more thorough job of cleaning jet ways and running. 016" wire thru pilot. After reassembling back on bike, turn on taps and lots of leaking...seemed to be from float gasket and even rubber boot. Pulled bowl, found float to be too high...my fault for not pressing just the plastic tab instead of needle head while measuring two mm down from bowl lip surface. Back on bike...all good, except after a few minutes with taps on, some small sheen of fuel can be seen at the banjo. Has a new plastic filter and new gasket under bolt head. Maybe one drop every ten minutes.
No matter for now...she starts on three or four kicks cold, choke on. Idling high...but adjusts down with idle screw...and then pilot screw seems to have an effect for the first time. Try to set it just under 1k but she is erratic and keeps dying there. Seems stable at 1200-1500... time to ride!
Take her along side streets and alleys to get in a groove. Brake is working, definitely needs full four finger pull to stop well...I'm very used to two finger pull on Bonneville.
I after ten minutes I stop and try idle tweaks...no good, still stalls below 1200 pretty easily. Might have manifold air leak, warpage on float bowl seal etc. Might also be ignition timing as I have only checked points once and need to revisit soon.
Did quite a few laps of neighborhood...not ready for urban street warfare at this stage...too many things happening between brain, hands and feet right now.

"Idling high...but adjusts down with idle screw...and then pilot screw seems to have an effect for the first time. Try to set it just under 1k but she is erratic and keeps dying there. Seems stable at 1200-1500..."

FWIW, I cd never get a reliable idle under 1000, settle for 11-12 now, even after the "wire in the idle jet" routine. Which BTW, went fine by just removing the mixture screw after counting the turns. Used to drain the fuel, pull the carbs, yama yama. After reviewing Bushman's tips http://www.jba.bc.ca/Bushmans Carb Tuning.html and seeing he's resigned (thanks to the brilliant ethanol program) to doing this every spring, and now goes straight to the mixture screws, thought I'd try it. Much simpler, just as effective.

Ok float diddle got pilot screw semi in effective range, so my 1st thought is go a bit more in same float adj direction to see if pilot air screw can further tame the 'high' idle. Good ign. time and carb tune easy allows 700 rpm but that's not practical safe in real world stop/goes stalls so 900/1000 is public use target. Once dialed in its handy to install thumb wheel slide stop screws to set idle low for show off or self pleasure but twist a bit each one for reliable transportation. Oh yeah try hobot greaser trick on slides, if solves most or all the low down steady happy sounds think about anodized slides, one half cutout size richer, #3, to make up for the beaten wider Amal bores and noticed more off idle throttle response. Then back to fine tuning worship rituals till Norton God smiles and ya start wearing out rear tires w/o care.

"hobot greaser trick"....
OK, I give, please explain or link to previous verbage.

Is it anything like the great LunMad YouTube videos on Amal work? He uses grease on bowl gasket, but didn't do anything with the throttle slides after "glassing" the bowl level.

Put axle grease smear on slide/bore which temporary, 100ish miles, seals leaks from intake pluses and engine bounce beating that wear the slide/bore air leak clearance away for over fast idle mixture flow no matter what, to see how much that improves or not to evaluate this common factor affecting your situation. Can't really finish carb details unless the ign time is darn right, which my down dirty way to know is adv. ignition to hint of back fire on KS then retard barely til it doesn't. Float level is most important base line to get right, once ya do then the rest suddenly works as advertised here. A fully fettered Commando may be the easiest to start and operate in public with plenty reserveds than any other cycle sold as easy as reliable or even more so if ya ever owned a modern of check in on this or that model forums devoted to ongoing rescues and let downs. Fully fettered Cdo's usually start first kick on good almost flooding tickle with throttle shut, if not should on 2nd 'kick' or rather step down on with WOT, if not tickle again and crack throttle a bit, if not stop and check key on, fuel on, plug leads on, battery good, etc as abnormal not to start 1st or occasional 2nd try. Plugs may be a bit fouled from poor tune/misfires prior so clean them again to just to be sure, till getting 1 kick/step delight or a slightly depressing lack of perfection 2nd shot to get lit.

Another thing...within an hour or two of parking on CS, I find a small amount of thick black oily goo under the CS area. Been looking carefully to discover source. Does not seem to be form anywhere along engine casing, nor any oil lines or the filter. My oil in the tank is still very light/clear, not black like this stuff. There is no sign of leakage from the tranny (I replaced the greenish fluid that was in there with Royal Purple gear oil of proper weight,,,and it is actually purple).
I'm thinking this goo maybe from the swingarm assembly. Recall I removed the end cap to find thick blue axle grease packed in there. Scraped out as much as I could, hit it with brake parts spray cleaner solvent and then refilled with correct gear oil to top bolt hole. The goo is kinda like the same viscosity...honey like...but colour is much darker. Could be residue debris in the spindle bushings. In any case, it should become less prevalent as the remainder seeps away....then I'll re-top it and see if silicone sealer on the end cap will help...

Re idle speed.
Went out for a run today and checked the warm idle speed. Its around 1200 and steady. This seems to be a good compromise setting. A little lower and the engine dies when not fully warm, so that's not great.
This speed shows a healthy volume of oil returning so that is important.
No crunch going into gear, just a click.
Hate the crunch!

Glen