62 Atlas help

I've had a 62 Atlas in my garage for a few years, had some plans and posts on it a while back. I've never gotten the thing to run, except for once and the throttle stuck open. I would love some input on getting it going. It is hard to kick over.

I ordered a rebuild kit for the dual Amal carbs, but I'm thinking someone has lost parts to these carbs. Parts 1 2 and 3 from this explosion are missing. What are these for? I'm sure it doesn't help not having them.

Also, one of the two throttle valves has a small ding in it (the upper portion). The valve chambers also have some scarring which is part of the reason I think it got stuck open. Also, the carbs were not bolted directly to the engine like I have seen in most photos. They were mounted with an adapter and some hosing, they hung in space held in place by the hose. Is this correct or should they bolt directing to the engine? Should I just replace the carbs?

Item 1,2,3 are part of the air valve (choke). I don’t use them and if removed there should be a blanking screw blocking the hole. If the carbs are sketchy, replace. There should be a manifold between the carb and cylinder head and a phenolic insulator between the manifold and cylinder head. The tube between the two is a balance pipe for smoother idle and operation and recommended for use (I take it for what it’s worth and make sure it’s present).

There is no tube between my two carbs. The carbs are connected to the engine by some black rubber tube, looks like hard rubber car engine air line. I'll get some pictures of the carb I left assembled. There was no manifold on mine. I wanted to get the original Amals going on it, but I may just have to try the Mikuni single carb setup since I have the manifold for that, and the carbs. I bought a 34mm conversion kit from MAP while drinking one night. Any chance that will work?

Thanks

The Ruber is to isolate the carbs / float bowls / float needle from V I B R A T I O N .
Something a ATLAS is famous for . tho I met someone selling a few bits , decades ago
spare chain , new . etc ; for one He had riden NEW through Europe , at 90 m.p.h. .
Japanese bits fell off my pre unit Bonneville in a weeek , if not tightened .
So the mikuni would likely ' falll off' the Atlas . ( o.k. itd work o.k. but jetting is crucial)

Incorectly jetted / lean , the mikuni would be a disaster regarding melting pistons ,
You wanna lean out the fuel tank , and check the fuel taps flow good .
we used armoured marine fuel tube . old brittle hard plastic might be no good .



If you insist on the mikunio's , theyre as suceptable to aeration etc as anything else , so rubber mounting THEM is a good idea . Besides , it HEAT INSULTES THEM , so vapouriseation / fuel lock less trouble .

Ere's an idious Bonneville Mikuni Konversion . K&N foam type sock air cleaners , or the concertina looking ones'd be much better .

Crikey . thought'it'd dematerialised .

BELOW is yer Std. period ( 1967 ) RUBBER MOUNTED CARB SET UP .



Incidently 40 over 650 pistons'd get it to 530 c.c. odd . ROIT . the HEAD picture ! std was hard bonded black long ' truck ' / agricultural straight radiator hose . SO THEY DONT SAG .

MONOBLOCK are vastly better than Concentrics . Set Em up ON THE BENCH . get free & true action . swift unhindered return / closing . f'get the choke assy's . a hindrance .
Best is Dual Cable Throttle grip . maybe quick action . 1/2 the weight / drag , than fussy junction boxes , Dual Load on the top single cable curve / friction , dragging thropple .

Of Course a 40 or 45 weber D C O E or DHLA delorotto , youd only need one cable , Fit that well . ( on yr rubber mounts ) & a selection of filters available . if your having another beer .



Course you only need ONE , so no ' matched set ( which is dificult used ) required .
Tho a Corroded one could be trouble . work well on triumph 500s . 40 DCOE .

So a well set up set of Monoblocks , is gunna be best , for of Idle metering / Control & economy .

dress & file / lap any Burrs . Remove any corrosion ( and in the Tank ) SET THE FLOAT LEVELS ACCURATELY .
And New Fuel Tubing would do no harm at all . and dont use cheap & nasty hose clamps on it .Use These .





These are pretty simple & a pleasure to set up . Can getem near spot on straight off , if your keen & literate .
AMALS need ' Correct Jetting ' anyway . Never assume its right . CHECK PERFORMANCE is correct .Like the IGNITION / Timing . Must be SPOT ON .
a Magneto under leaky carbs or fuel lines is intresting . Aparently thats why they invented Fire extinguishers . Have one handy .
Warming up the bonnie on a cold day , flooded carbs meant you could warm your hands tho , when it spat back .
a GAUZE on the mouth is a Flame Trap .

If your keen & want it to go like snot .

" is hard to kick over. "

theres a Thing . !

theres a TECNIQUE . and you dont ' kick it over ' , You push it through . Seen the silly TX 500 Crank Posn. window ! You Posn Crank/ Pistons , & kickstart . and leap skyward .
You turn it through a few times first. From Cold .
A good hill can be really helpfull .

Theres a picture of Peter williams at the IoM start on a yellow one , with a telve foot kick start . or inches , anyway . The P R Commando start is longest . But that was W A Y L O N G E R .

High Comp etc an all ,



A darn good welder coould straighten & lengthen one .



one Im talking about went half way up the side panel . a bit of leverage . If Yr all scrawy . if Not , posn. 7 Leap On IT Warilly .

Understood. The single Mikuni isn’t a bad set up, figure out the jetting as said earlier and you’d be good. Call around and get a sample of what people use for jetting, some might chime in here. I had one on my Atlas and it ran okay. If you got the parts go for it.

The hard to kick through might because it has wet sumped and all the oil in the crankcase is causing you trouble.
Daytona does not look too far from Plant City, So this might be of interest : https://www.accessnorton.com/Norton...aytona-bike-week-2022-thursday-3-10-22.34610/ It is stated that trailering is fine. Bring the bike to the event and I;ve found Norton Owner type people to be willingly helpful.

Barff .





Same Injun . If youve got DUAL Mikunis , their wizardry should suffice .

One Id make it a 34 .

oops



GEES . ave yer ever seen anything like that KINK in the INTAKE . BLAAAGHEEEAH !

Fink yer riginal rubber mouted Amals might do the job .

Thisisa FILTER .



Foam sock / washable . For dusty enviroments .



In England back then , it only stopped raining on Sunday afternoons , so that tended to keep the dust down . Hence No Filters .



Is that the NORTON HOTEL .

Well , You DID ASK ! . !











You should have youre Amals well sorted , before your halfway through reading this lot !

NOTE : the link to fettling amal Monoblocks somewhat earlier in the proceedings . Adios .

http://victorylibrary.com/MONO.htm CLICK HERE .

For Masochists :

Sorry for the late reply, I've been tied up with a large order at work and haven't had a chance to get back at it.

Ok, so the use of the rubber hose and connectors for the carbs was correct. The missing parts for the choke can be replaced, and I have rebuilt the one carb, I might as well try them.

As for the extension for the kickstart lever, I had already swapped on a longer one. Rebuilding the carbs is about as far as my knowledge goes with regards to an engine. I know it ran once before I took off the carbs, I hope to get it back to there at least lol. I am willing to learn though. Once its running again, I know to check the plugs and post pics so you all can help me read them.

Also, thanks for all the info on adapting the Mikuni's, but I thought I mentioned it came with an adapter manifold.

My 1962 Atlas resolutely refused to start with the twin monoblocs ( bolted to head) but started first kick with a Mikuni. I also put a plate under the barrels to lower CR, Atlas was fitted with dished pistons to lower CR if yours has commando pistons it will be harder to kick.

Kicking over with a magneto requires a different technique than coils. A magneto produces more spark energy as the engine rpm increases ..... conversely it produces Less spark energy at kickover rpm.

The typical kickover technique is to rotate the engine past TDC with the kickstart lever. Then reset the lever and give it all you've got. With a Maggie, I rotate the engine until I estimate the engine is midway up the compression stroke, then wait 10 seconds to allow the compression to leak off thru the ring gaps, then reset the kickstart lever and give it my all. This technique lets the magneto fire into to less compression energy which produces a greater spark at low kickover rpm.

Of course, the above assumes the Magneto is in normal operating condition.
Get one of the inline spark testers to get a visual verification you are getting a good spark in the cylinder..

See https://www.accessnorton.com/NortonCommando/atlas-64-rebuld.30987/page-2#post-544586

Slick

Twin carbs are always a pain to set up compared to a single carb. IMHO for most riders twin carbs never really made sense. I suspect the manufacturers offered twin carb "sports" models more for marketing than any other reason. Twin "chopped" Monoblocs are particularly hard to set up because it is a real PITA to get to the air screw on the left hand carb. However twin carb bikes are not inherently more difficult to start than a single carb. I suspect your improved starting with a single Mikuni v. twin Monoblocs is simply the result of the Monoblocs being old and/or worn and/or improperly set up, and not the result of any superiority of Mikunis over Monoblocs. BTW this is not meant as a comment about the all around superiority of Mikunis v. Monoblocs or vice a versa. I'm just commenting on starting.