Atlas Questions

As already written, the carburettor is a diva!
If I understood correctly, your Atlas was running before, so it does now.
Take your time and give the starter a generous break.
Keep using the starter spray and don't forget to charge the battery.
Good luck
 
Thanks mate great help. Tomorrow I will check if I have spark on both plugs. I remember reading about the Zane starter technic, quick stabs on the starter button. Don't go too long. I will tone down the urgency and become more methodical. I was too excited about riding it finally.
 
Not even a pop?
Makes me look for a kill switch anywhere? Including stand, clutch etc?

Also, give the big connections on that start relay a clean and a smear of grease, just in case dirty connections are causing more heat than normal.
 
It's a 1987 model, probably too old for safety cutouts. I just did an NGK conversion on the 2 plugs Markus sent the manual link to. Nowhere close to the usual B8ES. The Bosch plug XR4 CS matches an NGK DR9 EA and the Champion A6 YC matches an NGK ACR8 EIX. Not even the same plug, It will be interesting to see what's in the bike now.
 
It is important/helpful, as described in the service information (unfortunately I only have it in German), to operate the accelerator pump several times (at least 3 times), i.e. to apply full throttle several times before starting and then to start without throttle.

Cold start/coke only if the temperature requires it.



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Go info, they all have their fussy start procedures. Today was 23c and I used the choke so I might have flooded it. Lots to try tomorrow.
 
On my ’old’ Atlas cold starting is an issue. I found that it requires 10 or more twists of the throttle, a very small amount of ‘choke’, no throttle and stabbing the starter. After repeating the process a few times it slowly comes to life. I leave it chugging away at low revs for a short period before slowly opening the ‘choke’ and allowing it tick over for a minute or two before starting to use the throttle and backing off on the ‘choke’ which is probably more of a fast idle really.
I didn’t have the Atlas that Vince now owns for very long and only rode it a couple of times. It started a bit easier than my other one, but as Clem will confirm it appeared to be sucking in air somewhere as the engine would start to rev without opening the throttle. We both assumed it was the old, probably original, inlet manifolds leaking.
I had a set of the alloy after market set on my other bike, which as part of the sale to Vince, I included in the sale along with the replacement Cox exhaust. Therefore, all that has changed since it was last running is the replacement inlet manifolds and exhaust, but why would the change of them make such a difference?
it’s possible it’s running too rich as the car carb does seem to over fuel at times Or conversely too much air and not enough fuel?
BTW I believe the bike hadn’t being used very often before I bought it.
 
Thanks, Andy more good info. Lots to try tomorrow. I am making a list of easy things to try first. I had visions of fitting the exhaust and Videoing me going for a ride but where is the fun in that? That 3 full pumps on the Accelerator pump and no choke was the way I would start the old bevel Ducatis I rode years ago, and they were kick start only.
 
I can echo Andy's starting experience! My Series 3 Atlas was a bastard to start - OK if I used it daily, but if it was left more than a few days it was always very slow to fire. A few twists of the throttle, partial 'choke', no throttle, hit the starter and hope for the best..... It would usually turn over quickly, but without a hint of firing. Lots of relatively short stabs on the starter, then eventually it would fire and run rough, not responding well to any throttle or changes to the 'choke' until it warmed up sufficiently.
Note too that the battery tray is very small, hindered by the exhaust routing, so this limits the physical size of the battery. Thankfully modern batteries can be sourced with a high CCA, so it does give you more options for suitable batteries. Keep it fully charged too!

Good luck Vince, it'll be worth the wait.... ;)

 
This reminds me of the Pantah starting issue where most of the power went to the starter motor not leaving enough power for the ignition. The fix was a relay strategically fitted to make sure it spun and sparked together. So has anyone got a pic of the swap to standard bike carbs you can apparently do when the mark 3 exhaust is fitted and they can go on? Is it worth the drama of a carb swap and can they be connected to the airbox?
 
If the issue is the carb, try and find a car boffin with experience of that type of carburettor, probably an old man now. They were used on many cars. I knew people back in the day who swore by them and could tune them to be as good as anything. They have so many adjusting and compensating possibilities that it is easy to go way off, a bit like suspension.
Of course make sure, like you say, that the starter isn't robbing the power from ignition ((I have no idea where the ignition gets power from on them) but it is not an uncommon problem.
My experience with bastard to start bikes often points to leaking valves, if you can do a leakdown test that would exclude this.
 
Struck another roadblock, I cannot get the spark plugs out with what I own. From sight, the plugs in it appear smaller than the 18mm ones in my 3c. I have a 5/8 inch plug spanner plug some tube spanners and there smaller than that I think, nothing attaches. Now comes the odd bit, Markus supplied the manual spec for plugs as Bosch plug XR4 CS matches an NGK DR9 EA and the Champion A6 YC matches an NGK ACR8 EIX. The latter are Irideam but a different hex, Not even the same plug. The first one is an 18mm which by eye it isn't and the second one is an Iridium that matches a 16mm, they had a similar one at Repco that fitted my 5/8 inch but the ones in the bike don't fit it. Maybe I need a thin-walled plug spanner but what size specifically? I get a spark from both leads but that doesn't mean the plugs are firing. I am charging the battery and will put the tank back on and try it with no choke and 3 full pulls on the throttle. Be great to get new plugs though. Hope it's as simple as fowled plugs.
 
It lives finaly. And what a stupid reason why it wouldn't start. I was generally going over the bike when I got it home and found ZERO throttle freeplay, I like some but minimal freeplay so I put it down to people like what they like and adjusted to my liking and thought no more about it. The clutch also was the same so I dialled it to where I like it. Then 4 days of refitting the exhaust happened and after that, I wanted to ride the bloody thing so then there was nothing doing starting-wise. I made a list of things to try and after the really easy stuff failed I tried taking the airbox lid off and squirting Ether directly into the carb while spinning it over and it fired and Idled at 6000rpms. I killed it immediately. So what the hell, sticking Choke? NO. Sticking throttle NO. Why was it revving its tits off? The throttle snaps shut and it's got 3mm of Freeplay, what the hell is going on? And then I noticed what looks like the idle adjuster thumb wheel and its 15mm away from what it looked to contact where the throttle cable connects, the throttle connection to the carb bolts to the carb mount, and its 8mm alan bolt is LOOSE. I get my brother who BTW nearly shits himself with these full revs starts, to push on a long screwdriver as I tighten this mounting bolt and it moves the whole ball and wax to where it should be and the bike now starts and idles BEAUTIFULLY at 1200. I am guessing when Andy fitted the CNC inlet manifold the throttle cable holder moved and stayed there till I just found it. So it wouldn't start with full choke and 3/4 full throttle with the loose bracket plus me activating the accelerator pumps like crazy, you think I flooded it MAYBE? To be honest that's a bit of a death trap so I will make sure it never comes loose again. So I learned a hell of a lot about my new bike doing all this stuff. I might even go for a ride around the block Tomorrow.
 
Vince said:
It lives finaly. And what a stupid reason why it wouldn't start. I was generally going over the bike when I got it home and found ZERO throttle freeplay, I like some but minimal freeplay so I put it down to people like what they like and adjusted to my liking and thought no more about it. The clutch also was the same so I dialled it to where I like it. Then 4 days of refitting the exhaust happened and after that, I wanted to ride the bloody thing so then there was nothing doing starting-wise. I made a list of things to try and after the really easy stuff failed I tried taking the airbox lid off and squirting Ether directly into the carb while spinning it over and it fired and Idled at 6000rpms. I killed it immediately. So what the hell, sticking Choke? NO. Sticking throttle NO. Why was it revving its tits off? The throttle snaps shut and it's got 3mm of Freeplay, what the hell is going on? And then I noticed what looks like the idle adjuster thumb wheel and its 15mm away from what it looked to contact where the throttle cable connects, the throttle connection to the carb bolts to the carb mount, and its 8mm alan bolt is LOOSE. I get my brother who BTW nearly shits himself with these full revs starts, to push on a long screwdriver as I tighten this mounting bolt and it moves the whole ball and wax to where it should be and the bike now starts and idles BEAUTIFULLY at 1200. I am guessing when Andy fitted the CNC inlet manifold the throttle cable holder moved and stayed there till I just found it. So it wouldn't start with full choke and 3/4 full throttle with the loose bracket plus me activating the accelerator pumps like crazy, you think I flooded it MAYBE? To be honest that's a bit of a death trap so I will make sure it never comes loose again. So I learned a hell of a lot about my new bike doing all this stuff. I might even go for a ride around the block Tomorrow.
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Well thank f**k for that! 🤗
 
It was a shock suddenly bursting into life and revving out, but it was a relief as well. Not even a pop was worrying. It now starts so easily and idles like a champ. It needs a few laps of the block to get hot then an oil change including Reds Magnetic drain plug fitted ready for next Thursday's first serious ride. There are a couple of wrinkles though, it seems reluctant to select neutral. Some clutch drag, looks like there might be some clutch drum filing needed and some of those Kevlar plates if the supply of Kevlar returns to normal. Big demand in Putin's Arsehole Area. The other issue is I underestimated how big the muffler is and how close it is to the plastic side cover. I orders 2 kits but need 3 more of the heat-resistant alfoil stick-on tiles it needs so melting is avoided. They won't arrive before Thursday's ride, so it's either my pants and leg that might burn or the plastic side cover.
 
Vince said:
It was a shock suddenly bursting into life and revving out, but it was a relief as well. Not even a pop was worrying. It now starts so easily and idles like a champ. It needs a few laps of the block to get hot then an oil change including Reds Magnetic drain plug fitted ready for next Thursday's first serious ride. There are a couple of wrinkles though, it seems reluctant to select neutral. Some clutch drag, looks like there might be some clutch drum filing needed and some of those Kevlar plates if the supply of Kevlar returns to normal. Big demand in Putin's Arsehole Area. The other issue is I underestimated how big the muffler is and how close it is to the plastic side cover. I orders 2 kits but need 3 more of the heat-resistant alfoil stick-on tiles it needs so melting is avoided. They won't arrive before Thursday's ride, so it's either my pants and leg that might burn or the plastic side cover.
Click to expand...
Once I worked on a old tractor, a Hannomag R 12. diesel, one zylinder, two stroke with roots compressor. It did not start at all. I found a ball which worked like a vent in the pump was missing and put any ball which fitted in. Tractor starts at the next try with full revs, maybe 2000 and awefull noise. I was totally shocked. I had no idea how to stop it, no ignition key at the diesel. So I drove against a wall and stopped it with the coupler in a high gear.

Did not think about opening the diesel pipe….
 
I was happy to have a working KILL switch, I tried starting it 6 or 8 times with the same result and it took a while to find the reason why it was doing it. I am used to seeing cables entering the top of the carb in a permanent fixed way,or a solid frame that connects to multiple carbs not attached to a bolt-on bracket that can be moved to allow the carb to be set at full throttle by itself. It was so subtle it took a while for me to notice it having never seen this system before. I then noticed what looked to be the idle adjuster and it was 15mm away from touching anything and which didn't look correct. I am a very happy camper that it's now going very well and I didn't need to crash it into a wall to stall it. Good story Andre.
 
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