joe czech
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whac-a-mole problems and alton e-start (alternator rotor) timing marks.
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Back in the early 70's I bought my first low mileage used Comando cheap because that same thing happened to it. While getting it going again I noticed that the nut would get tight before pressing against the rotor enough. I seam to remember the nut not being threaded all the way through and getting tight before fully pressing the rotor or maybe it was bottoming against the flat of the crank. The fix at the time was to fit a thicker washer under the nut. You can't go too thick on the washer or it will hit the timing mark stamping on the cover. This is all memory from 50 years ago but I'm almost certain it was the nut thread problem. Wouldn't hurt to check that.
It does not rely on the key. I’ve just had a key sheer, I have to admit that I was disappointed.
The drive is made by the 70 pus foot torque on the nut clamping the rotor solid.
Alton states that you should use loctite on the thread.
I have just cleaned mine up as described lictite and torqued the nut. I’m hoping this will be the last time this happens!
The drive is made by the 70 pus foot torque on the nut clamping the rotor solid.
Alton states that you should use loctite on the thread.
I have just cleaned mine up as described lictite and torqued the nut. I’m hoping this will be the last time this happens!
johnfitzw
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Here's how I fixed mine. I keyed the Alton sprag into the engine sprocket, after talking to Paul at Alton. It was a real mission, getting the sprag keyway aligned to with the drive recess in the alternator... You could give up on the rotor key and just use the engine sprocket drive arrangement, but I wouldn't recommend it - there's helluva twisting force applied if you get the occasional standard Pazon / Boyer kickback when starting.
swooshdave
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I didn't realize the Alton relied on the key to hold the sprag. I don't think that part of the crankshaft was ever designed to take that kind of torque. It was just designed to hold the rotor which as minimal stress as it's just spinning.
swooshdave
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So am I correct that the Alton relies on the key or not? I don't mind be corrected.
This post seems to say yes: https://www.accessnorton.com/Norton...ternator-rotor-timing-marks.32685/post-523559
This post seems to propose a solution. https://www.accessnorton.com/Norton...ternator-rotor-timing-marks.32685/post-523572 I'd expect Alton to come up with a solution like this at some point.
On my CNW E start : the Lucas rotor nut needed a retorque after only a few starts on the bench. and the nut turned about 1 flat. But luckily the belt drive does not need oil and I had not installed the primary cover, so it was just a matter of doubling checking all the fasteners. I know with aluminum belt pulleys that is to be expected. And now I will even recheck that again after about 80 miles on it.
swooshdave
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Retorqing even after using locktite?
joe czech
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lots of good posts and replies, but still a little confused. so am i to understand that the woodruff key is only for alignment, and what holds the sprag clutch/rotor assembly is the clamping force of the nut and the spacer that goes between the sprag and the crank engine sprocket? looking at my crank, i MAY have bigger problems here - look at the pic - is the keyway for the engine sprocket and the keyway for the rotor supposed to be be aligned to each other? have to plead ignorance here - not enough experience on these twins. if those keyways are supposed to be aligned, it looks like the engine sprocket's woodruff key may also sheared and the sprocket slipped on the crank. if that's the case, i may have bigger problems and significant damage to the crank end. ?????
The blue locktite is not all the at strong, But I did fully remove the nut after I saw the nut would move and cleaned everything up and started from scratch, I put a witness mark with a ink marker, so I knew how much more it tightened/ turned. The aluminum pulley taper makes it necessary as everything is changing and stretching and seating. I expected it to happen and it did. Most of my bikes are equipped with belts. Hence the re tork.
ntst8
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I would loctite at the retorque.
ntst8
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That is the way I see it, and the clamping force will reduce if the drive sprocket (or pulley) eases further on to the taper after a heat cycle or two, hence the retorque suggestion.
That I did, and will do at the next tork check.. The last thing I need to do is tear up my crank or ruin the sprag..
And the witness marks on the nuts, to show what you done at the retork with a fresh coat of blue on the cleaned and degreased. threads , Just a tight fitting key and make things change too. The key fit needed to be addressed and doctored up some if needed.
kommando
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No, the nut on the end of the crank should be tight enough to hold all the parts in place, the key is just to locate the rotor for timing not to drive the rotor. The BSA B25 had soft mainshafts which let the nut unscrew and the rotor started to wander, the fix was to have dowels in the engine sprocket to fix the rotor in position.
cliffa
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No you’re ok Joe, the key ways are supposed to be 90° apart.lots of good posts and replies, but still a little confused. so am i to understand that the woodruff key is only for alignment, and what holds the sprag clutch/rotor assembly is the clamping force of the nut and the spacer that goes between the sprag and the crank engine sprocket? looking at my crank, i MAY have bigger problems here - look at the pic - is the keyway for the engine sprocket and the keyway for the rotor supposed to be be aligned to each other? have to plead ignorance here - not enough experience on these twins. if those keyways are supposed to be aligned, it looks like the engine sprocket's woodruff key may also sheared and the sprocket slipped on the crank. if that's the case, i may have bigger problems and significant damage to the crank end. ?????
you can see mine here..
Journey into the unknown..
Hi folks, This weekend I plan to commence the fitment of my Alton starter in combination with the existing Maney outrigger. As I've not stripped a Commando primary before and I have limited imperial sockets could somebody kindly tell me what spanner sizes (or A/F sizes) the clutch and rotor...
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joe czech
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SUPER!!! one additional question - i'm assuming the keyway for the rotor aligns with TDC on the crank - correct?No you’re ok Joe, the key ways are supposed to be 90° apart.
you can see mine here..
Journey into the unknown..
Hi folks, This weekend I plan to commence the fitment of my Alton starter in combination with the existing Maney outrigger. As I've not stripped a Commando primary before and I have limited imperial sockets could somebody kindly tell me what spanner sizes (or A/F sizes) the clutch and rotor...
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