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I’ve always liked this model:https://bringatrailer.com/listing/1971-norton-norton-commando-ss/
I believe everyone loves a vintage / classic Norton like this...
everbody who did not own one at the time.i've still got mine ,it will probably be a retirement project. i had it as daily transport for years, keeping on top of te repairs and maintenance was a nightmare.I bought a V65TT to use during winter, to keep my nice norton clean. after finding out you can ride a bike witout spending your weekends spannering, i never looked back. currently own 6 guzzi's...and a norton.
I'd ride any one of my Norton's anywhere ..except for my 1948 350 Manx.... I can't bump start it without help ...... so what if i have to keep a rag in my pocket to wipe off my boot once in awhile .. I just think Phil is jealous ,,,,, he's not living up to his tag line , living on the edge
Well you'd be wrong All I see when I look at any Commando or it's derivatives is a crankshaft with the rigidity of wet spaghetti, (so bad it needs barrel shaped main bearing rollers to accommodate all the flex) Amal carbs that are worn out before the first service mileage, Lucas electrics and fiddly high maintenance "Isolastic" engine mounting system designed to keep the whole vibrating, oil leaking lump of a mechanical mess in the frame without the rider losing their fillings. Nortons final insult to the British motorcycle buyer. Ciao
If you knew anything about Commando's you would know they never had barrel shaped roller bearings.
When did walking beside a bike with a blown engine started being considered living on the edge?
Norton’s had their problems which can be fixed, but so has MG.
the difference is MG managed to fix the issues, the norton factory didn't during the years i ran my norton 25.000 km/year, my girlfriend ran a V7sport. both 1972 , both same mileage.That V7sport was stupidly reliable in comparison.
Norton Superbend bearings are barrel shaped? I have never examined one but some Norton restorers say the are a normal shaped roller with the ends rounded off slightly....
Super blends installed on the right, original oil pump on the left which has to be replaced some day. Even though the Norton has been rebuilt, it still leaks some oil but I’ve pretty much eliminated most of those issues. The Daytona has a weird oil weep from the right head which I can’t find, thought it was a porous valve cover but that isn’t it, so it shares an issue with the Norton. My 07 NORGE dodged the bad oil pumps which led to some engine’s going bad or at least had to have the oil pump,changed. My CX engine started clanking right before I made it to the garage, bad crank shell so the engine was rebuilt. Then I found out there were a few bad batches of shells installed at the factory and I got one of those engines. I never owned a hydraulic Guzzi engine but those were an issue, then the Carc equipped bad roller issues…….Norton’s had their problems which can be fixed, but so has MG.
I can tell you where your Daytona head is leaking and how to fix it.Ciao
Cool, the hose is not the source. Where do you think it's leaking?
The 1968 to 1971 20M3 and 20M3S 750 Commando followed on from the Norton Atlas with a ball bearing on the timing side of the engine and a roller bearing on the drive side which worked fine unless they were over revved.For 1972 the engine case was changed which included a revision to the dry sump scavenge pick location (which reverted back to the pre 1972 location for the 1973 850)That 1972 engine also got a revised breather system with an outlet at the rear wall of the engine case replacing the cam shaft breather of the earlier engine that had a hose running off the end of the cam on the left hand side of the engine back to the oil tank.Why do a lot of British motorcycle engines leak, because of poor crankcase evacuation. I bought two of these reed evacuators for my Commando's from Jim Comstock. These replace the large plug under the engine so maintain the gauze scavenge pick up as per stock and the case evacuates via the tower with a hose return to the oil tank. That fixes two problems straight away.That reed valve breather fits all 850 Commando's and the 1971 750, it will not fit pre 1971 Commando's due to the lower frame loop cross tube being rearward (moved in 1971 forward) or the 1972/1973 engine case as there is no provision to fit it.Stock, oil passes from the floor of the engine case through the gauze and back to the scavenge side of the oil pump.The 1972 case did not have this. I elected to machine a copy of sorts for my Eldorado (That would be the bike folk lower the oil level on so it does not exit via the poor breather system)Being a wet sump engine it has an internally baffled engine case port to feed it and the breather has a reed valve with separator and case return.As far as the 1972 Commando I do not know what the bearing set up was for the first bikes produced, ball and roller or dual roller (Combat was just a performance spec that could be added to the standard bike for that year)Why did the crankshaft bearings start to fail is speculation at best, even with the higher compression on the Combat spec a sensible rev limit would have seemed prudent especially with a 19T front drive chain sprocket. There was talk of cavitation, the new breather not being better than the previous method, the new small un gauzed oil pick up could allow free passage of small debris back to the oil pump.The high compression (and low geared) Combat seemed to have the problems so the recall was for the Superblend bearing which was a R&M bearing (or RHP) with revised roller ends on the parallel roller.The barrel roller myth of near 50 years started there.Obviously anyone who actually works on Commando engines or knows bearings would know a barrel shaped roller on a flat race would have no stability or load carrying ability (and would not repeat or copy that)That early MRJA30 bearing had the hand scribed /6, the FAG NJ306E even if used in later part of 1972 is more so associated with the new for 1973 850 engine (imho)Any failing with the gearbox layshaft ball bearing came down to the cage material which was known to fail on the so called Portuguese bearing in the 1973 on 850, it could start to fail (The kick start lever would start to pivot giving a warning something was wrong being on the end of that same shaft) Failure could lead to a locked rear wheel.There are two replacements, a roller bearing or an upgraded ball bearing with better cage, I elected to put rollers in both my Commando's with the shafts shimmed for maximum engagement in first gear. I found this which is bearing related to the Commando and shows the clipped profile of the so called 'superblend parallel roller.https://www.nortonownersclub.org/sites/default/files/Main-Bearings-v1.1.compressed.pdfI have no real loyalty to any marque but look at them independently for what they good and bad and a lot of the bad can be rectified with time, patience and money. The Commando in general (imo) needs a lot of specialised tools to work on, without them it will soon become a chore or risk of a bodge.I would rather have a Triumph TR5T Trophy Trail over a 1971 SS as per the thread.
They did after you had to rebuild them when they destroyed the std bearings due to crank flex. Any decent engine builder for a Commando that knows his stuff uses the "Superblend" mains with the barrel rollers to accommodate the crank flex. Same as the gearbox upgrade to roller bearings from bushes. As a matter of fact if my memory serves me from 40 years ago Norton used them in the later Combat engines after all the earlier ones started blowing up, so they did indeed at one point come with Superblends. I have been inside a commando engine and transmission. EDIT.....I did some research.https://www.real-classic.co.uk/2018/02/15/classic-techniques-superblend-bearings-part-one/https://www.real-classic.co.uk/2018/03/16/classic-techniques-superblend-bearings-part-two/Ciao
Every garage needs a German, an Italian and a British air cooled twin.
i'm doing fine , with at least a dozen italian twins, a britisch twin, even a japanese one... ( my first bike ever!) Not sure about the german twins, the ones i sampled were seriously lacking character. may be if i retire, and the italians become too much to handle ?
Have a read through this thread I made and let me know if you have any questions. Try the rocker cover retaining screw holes in the head first if it gets oil on the outer head fins. If it's from somewhere at the front cam drive area it will be the cam bearing support block. All assuming it's not something obvious like a weeping head gasket.https://www.v11lemans.com/forums/index.php?/topic/22369-porosity-a-retrospective/Also this on the last page. The cam bearing support.https://www.v11lemans.com/forums/index.php?/topic/20664-v11-daytona-project/page/26/#comment-254707Ciao
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