Atlas Questions

Vince said:
Today I extracted a diget and decided to tempt fate and try another club ride on the Atlas. I had al sorts of plans about doing some test rides first but that didn't happen so up at 6am and off I headed to fill the fuel tank first. The last ride had me suddenly stopping after the bike travelled for 5 minutes. I had suspected it was borderline on reserve and was starving for fuel for that reason, didn't even think this last time. And then starting after a few minutes on the sidestand or so I thought. Today I avoided that expressway tunnel just to be safe. And then it happened again. At approximately the same travel time but in a much safer spot the bloody bike suddenly stopped again. Fuck me this again. But this time I noticed something earlier when getting fuel. Everybody drags out the old chestnut of the fuel tank breather getting blocked. When I filled up with fuel I noticed that the fuel tank breather hose, very typical dirt bike style had kinked right on the cap and pinched off. I tried manipulating it so it opened up but that didn't work. So after the bike stopped I pulled it off and the bike started and ran well for the whole ride, exactly 150ks with quite a bit of expressway. My bloody expensive tank bag has a cavity formed that is supposed to clear this breather hose, but apparently not. Easy fix, so simple but also easy to not notice especially if you tick this off with a specific tank bag removing any thinking of this as an issue. I also did an MPG check, I was curious as to how efficient the huge car carby might be, and it's pretty dam good at 48.6 MPG. No idea what that converts to metric, I never swung that way for MPG or tyre pressures. The main issue the bike needs now is for me to back off the rear shock preload so I can get both feet down, the way it now makes the bike very nervous at slow speeds, it steers really fast, it needs to be way more stable especially when filtering traffic. A lighter clutch pull and getting neutral would be bloody good as well.
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Vince,
You might try fitting a light spring over the tank breather pipe to prevent it creasing where your bag sits.
If you lower the rear ride height not only will your feet touch the ground easier but it will also have the effect of giving you more trail on the front thus slowing the steering down. Win win.
 
My thinking too Chris. I tried to set the rear sag at 1/3 of travel but that results in pretty much an unusable seat height close to 900mm plus it tips the bike forward into its nose reducing trail and stability as well. That might be ok on a lightweight 120kg offroad but on a top-heavy 200kg Adventure Bike, not so much. That fuel tank breather hose only comes into play with the bike on its side keeping fuel spill away from the hot bits. The main fuel tank hole bearly allows a Petrol station fuel hose into the tank making it hard to see when it's full. It probably will get a spring like you said Chris to support the hose.
 
Vince said:
fuel tank breather
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*aaaaahh* - with the symptoms our very first thought should have been for this 'classic Atlas gaffe'.
That (80th style) breather tube drove me crazy. The daily hazzle with tank bags, squeezed tubes, broken tubes, broken nippels, fiddeling the tube back into the 'fork nut hole' at each fuel stop, getting stuck bc of underpressure ( ... tank bag)
A solution had to be found : luckily this '40mm lockable and breathable cap' for 'german mopeds' fitted perfectly. What a relieve ! Adios the hazzles listed above + much easier to open/tighten e.g. with icy fingers - and no passing rascal would pour sand or water into the tank.
Maybe the best of "lite fixes" of "daily annoyances" on my Atlas. BTW it got 'Africa approved' (taking regular fesh fesh showers)
Maybe you can find it in your country:
www.motorsportgoetz.com

Tank cap with lock Hercules Puch Zündapp Kreidler KTM 40mm, 12,79 €

Goetz onlineshop motorcycle ATV Gotz Quad Moto Cross Off Road Tank cap with lock 40mm for Hercules Puch Zündapp Kreidler KTM lockable with two keys
www.motorsportgoetz.com www.motorsportgoetz.com
 
Maybe, I did search for a cap without an exposed nipple. At first, I thought Acerbis might have made the tank, they do a lockable cap so I went to see the Oz distributor before I noticed the fuel cap had a name on it. Fermi, I think. There a huge Italian fuel tank manufacturer, they do thousands of different caps including Feraris and Agricultural tractors. So I emailed them but they were discontinued. So thanks for the new lead, the detective work continues.
 
The most annoying issue I have with the Atlas is how impossible it is to get into neutral when stopped. Even with its upper clutch adjuster set to zero freeplay the clutch doesn't fully disengage. I had a play today with it on its fully jackable engine lift, unless the upper clutch cable adjuster is absolutely zeroed out with no freeplay I still get engine drive to the rear wheel causing clutch drag and the bike to creep forward. I am going to have another fiddle with the lower cable adjuster and hope I can find more clutch lift with it. It attaches and works by pulling the cable from the rear of the bike towards the front and has some complicated links between that and the clutch rods, completely different to any other bike I have seen. Really keen to get this fixed if I can.
 
It doesn't matter where I do the clutch adjustment it still drags. Before I do anything radical I am going to try changing the oil from Dino Penrite 20w50 to their full Synthetic and see if that reduces the clutch drag. With the rear wheel off the ground the bike selects neutral so easily but the rear wheel just still turns slightly even rubbing against my foot, the bike needs zero freeplay to avoid it creeping forward but still won't select neutral with that driving rear wheel still just happening.
 
I had a long hard 2am think about what the clutch adjustment needs and that's more throw and there is a way to do that. It works off a long vertical rotating rod, the clutch cable lower nipple attaches to a fork on the bottom of that rod. That nipple is movable along the cable and locks on via a grub screw, never seen that on any standard cable ever. If I move that nipple down the cable 10mm or so that should allow the vertical sharf to rotate enough to allow the adjuster to extend 3 or 4mm which will give the same extra push to the clutch central rod hopefully getting more clutch lift and removing the drag I am getting. There even looks to be a shiny witness mark showing that this was happening in the past. It might even lessen the pull needed on the lever, Maybe. It's one complicated mechanism down there transferring movement to all 4 compass bearings. I guess it was done to avoid the original exhaust routing that went right under the carbs where typical clutch cables also run.
 
Vince said:
I had a long hard 2am think about what the clutch adjustment needs and that's more throw and there is a way to do that. It works off a long vertical rotating rod, the clutch cable lower nipple attaches to a fork on the bottom of that rod. That nipple is movable along the cable and locks on via a grub screw, never seen that on any standard cable ever. If I move that nipple down the cable 10mm or so that should allow the vertical sharf to rotate enough to allow the adjuster to extend 3 or 4mm which will give the same extra push to the clutch central rod hopefully getting more clutch lift and removing the drag I am getting. There even looks to be a shiny witness mark showing that this was happening in the past. It might even lessen the pull needed on the lever, Maybe. It's one complicated mechanism down there transferring movement to all 4 compass bearings. I guess it was done to avoid the original exhaust routing that went right under the carbs where typical clutch cables also run.
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Same setup on the 500s.
 
So, What I am thinking is adjusting the clutch cable so the threaded plunger sits slightly to the left of the clutch rod centre as you see it from the left of the bike, not dead centre like it is now. Is that typical of what's done to the 500s. It's hard to explain but once seen it makes sense to me. The adjuster swings as it turns and moves into contact. I am hoping I can get a mm or 2 more push with the threaded adjuster a bit more extended towards the engine.
 
With the clutch lever fully deployed, the included angle between the cable and actuating lever under the crankcase should be close to 90° or slightly over. This affords close to maximum turning angle of the actuator shaft. Either adjust the cable or adjuster screw accordingly, easy-peasy.

piet
 
I think you might have that arse about Piet. I suspect you're thinking of the mechanical advantage, which is indeed maximum when the cable and lever at the crankcase end are at 90°. But the clutch throw (or clutch shaft rotation? - I'm not familiar with the Atlas) is minimised. If you want to achieve more rotation of the lever arm, you need to set a more acute angle between cable and lever arm, which I think is what Vince is talking about. But the trade off is that it'll be harder to pull the clutch in.
 
Its in a hard place to even get a look at the angle. I tried a couple of spots along the clutch cable for that movable nipple and it makes zero difference. What I am finding is ware on the adjusting threaded pin end and a divot where that threaded adjuster pin hits. None of these bits should spin, only rub while swinging into contact. This wear might all add up to maybe 1 or 2mm, it doesn't take much to affect a clutch working correctly. I once made a clutch rod for my 3c out of silver steel, it lasted about an hour, wearing it away by a couple of mm in that time. Hopefully, Piet has some replacement bits. I absolutely hate sitting at traffic lights with the clutch pulled in, I tried getting neutral while still moving and that also doesn't work. The only thing that does is killing the engine, getting neutral and restarting.
 
Quick question, what's the deal with reclaiming lost lengths on engine valves with Silite, no idea how that spelt or is even usable in this case. Could you use that to reclaim wear on part of the movable button, that bit makes up the outer bit of the clutch push rod. Or maybe TIG it to take up wear.
 
Vince said:
Its in a hard place to even get a look at the angle.
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Sometimes when trying to get a good look at something inaccessible, it helps to poke your phone down there and take a photo.

As mentioned above, I'm not at all familiar with the Atlas clutch, so I'm struggling to understand what you're describing with moveable nipple, threaded pin, etc. My comment about Piet's post was based on theory of simple machines (levers and such) rather than any specific knowledge about the bike.
 
Movable nipple, think HQ Holden bonnet cable. Yep, the bottom nipple slides down the cable and locks off with a grub screw. The odd thing is Andy got me a spare clutch cable and it's just that, 2 fixed nipples just like every clutch cable ever made. There is a free play adjuster at the bottom that has a threaded bolt, it bears on a captured button that contacts the outer clutch rod. I will try taking some pics.
 
Vince said:
Quick question, what's the deal with reclaiming lost lengths on engine valves with Silite, no idea how that spelt or is even usable in this case. Could you use that to reclaim wear on part of the movable button, that bit makes up the outer bit of the clutch push rod. Or maybe TIG it to take up wear.
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I think you might mean Stellite:

Stellite - Wikipedia

en.wikipedia.org en.wikipedia.org

Can be welded to the stem tips of valves to provide wear resistance. The cam followers of Triumph T160 Tridents used Stellite sections, silver soldered to the main body of the follower. I imagine that other pushrod Triumphs of the same era used the same technology. But I don't know how it might be applied in your application.

Cheers,

bazzee
 
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