classic motorcycle forum

I d never get chroming done again.....since hexavalent salts were banned,the platers all say it doesnt last......I would get stainless rims,or just go with paint........where I had the wheels professionally lined,it seems a etch was used,which has lifted the chrome where the lining is........Fortunately,the tank wasnt done by the same guy,and the chrome is still 99%..with one little patch thats visible in sunlight.

Jap bikes use the same process on plastic and pretend its chrome...........just the plastic is a bit thicker.

The frame number is the identity part.......engine number probably changed when the rods came out for a look around...The frame numbers on the early fifties Nortons were pretty roughly stamped,and sometimes hard to decipher......So the story goes,when a bike was finished and test ride OK,an old fellow called Pops would come down from the "counting house"and apply the frame number........he was said to always have a big bottle of strong smelling cough mixture with him,and was frequently tipsy...When Nortons went bust due to poor sales ,and racing expenditure,the comnpany was offered to the Birmingham makers,who declined...money man C.A.Vandervell died,and his son didnt like bikes.....Under a board of trade scheme,a subsidy was offered,and Charles Collier of AMC thought the price and subsidy were good enough.........AMC sent Jock West to Bracebridge St to sort things out.......Which included sacking Pop,and having Harold Daniell up before the beak for nicking stuff.......Daniell beat the rap....Jock West was not popular,and when he was made sales director for all AMC products,he got the big Yankee importers offside....including Sammy Cooper,who was selling about half of all Matchless output.

Ive been "at it" for nearly sixty years ,and IMHO Norton twins wernt common.........mainly I suspect because Triumph s were.I seem to remember Nortons were always dearer than Triumphs and BSA s.....The early plunger Norton twins were also ugly bikes,and had tin chaincases ,something that just didnt sell in OZ...Pre 50 ,they also had the primitive outside linkage gearbox,which was also ugly.........Funny thing is the Norton SV singles were common in government fleets.....the Brisbane council had lots as mosquito sprayers and the rat gangs.....the PMG had them as linesmens  outfits,....probably all Big 4s..............As an aside.....the the arrival of the rat gang on their thumping Big 4s was a major event when I was a kid.........Sidecars full of  fox terriers..........the boss would stand up on the tank of one bike and read "The Prevention Of Plague Regulations 1907"......then give everyone to five minutes to round up cats ,chooks and guinea pigs.....Then the dogs would go to work......very exciting for a five year old.

Doesnt worry me what they do.........I know crazy prices will end in tears......Its getting so bad here you cant ride a bike on the road without some phone user running you down.

But is it?.......once the motor heats up,the scavenge return is just spurts and froth.......and would need a positive restriction at the return pipe to raise any pressure at the tee.........I know I always used to put my finger over the return in my A10 on startup to pressurize the rocker oil ,but once the sump is cleared ,oil return is spasmodic ,and hot oil is thin as water ,so the return pipe has no resistance to flow..........There is a bit of gravity feed ,if the rocker shaft is lower than the oil pipe outlet.............but in the singles,the head is a lot higher than the oil tank,yet the oiling still works.

The JAP 500 and 600 singles ex rotavators generallly have a mounting flange around the drive side crankcase......The ones that are nearly pure motorbike engine are the ones from Autotrucks,both 600s and 750 s,the 1000cc ones from Lister rail trolleys,and the starting engines that were commonly found on portable air compressors.Lister trucks had JAP engines almost exclusively(a few SA s) up until 1962,when the Lister family sold out to Hawker Siddely.......the autotruck era was over by then anyway.Ive seen claims that Listers sold nearly 3/4 million autotrucks......thats a lot of JAPs....Air compressors with Dorman and Ruston engines always had Jap starting engines.....And recently I found the bits to refit a JAP engine to a compressor ,so it could be restored.....They even have Amal slide carbies with a twist grip and advance for the BTH mag on the lever that engages the clutch to the pinion...A few chugs ,and a big 6 cyl diesel fires up....The roller bearing in JAPs suffer from brinelling due to vibration .

 like the adjustable magneto sprocket,about which ,the less said the better....Old bikes aint about rocket science ,just making sure nothing comes undone or falls off........