Yes, the plate. I knew I should have snapped a photo - but honestly there was nothing behing the plate at all. Just the shaft that the points cam rides on.
Yes, you are correct that I should have checked the timing of the points coming out - but sadly I didn't. It was just faster and time is an extremely limited commodity in my life, even on the weekends.
Cure for an ankle buster?
Moderator: ajleone
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Re: Cure for an ankle buster?
" but honestly there was nothing behing the plate at all. Just the shaft that the points cam rides on. "
____ Then exactly how is the points-cam held-set to the shaft ??
" you are correct that I should have checked the timing of the points coming out - but sadly I didn't. "
____ Well if you HAD done so and then found the ign.timing (normally properly) set near 22-degrees BTDC,, then without the expected 18-degree AAU included, you would've discovered your very-likely reason for not having obtained normal-power to rev up past 6-grand.
Do you think anyone had ever tried to reset the ign.timing before you acquired the Duke ?
Hopeful-Cheers,
-Bob
____ Then exactly how is the points-cam held-set to the shaft ??
" you are correct that I should have checked the timing of the points coming out - but sadly I didn't. "
____ Well if you HAD done so and then found the ign.timing (normally properly) set near 22-degrees BTDC,, then without the expected 18-degree AAU included, you would've discovered your very-likely reason for not having obtained normal-power to rev up past 6-grand.
Do you think anyone had ever tried to reset the ign.timing before you acquired the Duke ?
Hopeful-Cheers,
-Bob
PLEASE NOTE... If this-post is not-yet signed-off with '-Bob', then I'm still in the process of completing it,, and if not also included with 'DCT' near bottom as well, then I may edit this post's wording at a later time. - Dct.Bob
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Re: Cure for an ankle buster?
Then exactly how is the points-cam held-set to the shaft ??
Just by the screw that passes through the points cam lobe and into the end of the shaft. I have a feeling I must be missing something you are trying to tell me.
Do you think anyone had ever tried to reset the ign.timing before you acquired the Duke ?
It's possible...
The story I got is that the 2K mileage is accurate (but who hasn't heard that one before!)
Another story is that motorcycle killed it's first owner. (This could explain the 32mm forks since the originals might likely have been crumpled, and the off-brand front fender.)
In talking again with the previous owner that sold it to me, he admitted that the bike would not rev past 6K for him either.
I am going to touch base with him again to see if he attempted to time the bike.
Jim
Just by the screw that passes through the points cam lobe and into the end of the shaft. I have a feeling I must be missing something you are trying to tell me.
Do you think anyone had ever tried to reset the ign.timing before you acquired the Duke ?
It's possible...
The story I got is that the 2K mileage is accurate (but who hasn't heard that one before!)
Another story is that motorcycle killed it's first owner. (This could explain the 32mm forks since the originals might likely have been crumpled, and the off-brand front fender.)
In talking again with the previous owner that sold it to me, he admitted that the bike would not rev past 6K for him either.
I am going to touch base with him again to see if he attempted to time the bike.
Jim
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Re: Cure for an ankle buster?
Sounds likely the timing issue is the majority of problem though if it's running rich that would still need to be sorted also.
The aau behind the points plate should look more or less like this;

The cam that opens the points slides on to a tube that protrudes up from the aau like this;

... and that tube (that has a slot on the bottom) is actually what slides over the drive gear shaft and the slot engages a pin going across said shaft.
The tube part is held in tight by the screw in the drive shaft and the cam can pivot freely on the tube and is held in place by the two slotted ears that engage the pins on the weights.
So the cam itself, removed from/independent of the rest of the aau, has no obvious way to attach directly to the driven gear shaft without some modification/adaption. As Bob has mentioned, the fixed timing mod usually involves the simple method of tacking the weights in place so the cam can't move, as opposed to removing all but the cam portion.
I have the aau from the R/T (the 'aa367b' type made for 'magneto' operation) that I have no immediate plans for, if you'd like to give it a whirl I can drop it in the mail. If it works out that that's the way you'll go, you can use it until such time the you find another, they're not popular as many people covert to the battery type and as such can be had very cheaply.
Bill
The aau behind the points plate should look more or less like this;

The cam that opens the points slides on to a tube that protrudes up from the aau like this;

... and that tube (that has a slot on the bottom) is actually what slides over the drive gear shaft and the slot engages a pin going across said shaft.
The tube part is held in tight by the screw in the drive shaft and the cam can pivot freely on the tube and is held in place by the two slotted ears that engage the pins on the weights.
So the cam itself, removed from/independent of the rest of the aau, has no obvious way to attach directly to the driven gear shaft without some modification/adaption. As Bob has mentioned, the fixed timing mod usually involves the simple method of tacking the weights in place so the cam can't move, as opposed to removing all but the cam portion.
I have the aau from the R/T (the 'aa367b' type made for 'magneto' operation) that I have no immediate plans for, if you'd like to give it a whirl I can drop it in the mail. If it works out that that's the way you'll go, you can use it until such time the you find another, they're not popular as many people covert to the battery type and as such can be had very cheaply.
Bill
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Ignition-timing's Mechanical-function
By: JimF...
" I have a feeling I must be missing something you are trying to tell me. "
____ Well actually I wasn't trying to TELL you something, rather I was trying to find-out whatever it is you actually have to work with there...
Since it seems you're sure you have nothing at all as a AAU, then I'm wondering if that which you do have is even a stock setup !? _ Cuz normally the body of an AAU is what's used to hold the points-cam while the AAU-body is held-down (by the screw) to it's drive-shaft.
__ Bill has nicely provided a very-good post which well explains pretty-much everything on this, (and in a considerably better fashion than I-myself would've done here), thus saving me from having to get any more detailed about it !!
So now hopefully you -(Jim) can clear us up on what-all is different in your case. - (A pic or two would be nice!)
__ Your Duke may be an early-65, but still, I'd expect it to be new enough to have come with a working AAU.
Have you checked your motor-number against the number-listings which list the recommended static-timing covering your particular issued-model ?
" he admitted that the bike would not rev past 6K for him either. "
____ At this point it seems likely that someone in the past swapped-out some original parts.
And it seems that you ought to source for yourself a working stock-type AAU, (as Bill has).
__ Did it not include it's 29mm SSI, either, (when you first got this Duke) ?
____ As a side-note, the pic that Bill has posted showing an AAU mounted down-inside it's cavity (behind where the points-plate is normally mounted), shows a points-cam with the longer duration that's intended for the battery-type ignition-system.
So YOURS ought look pretty-much the same except for the cam's lobe ought appear with a considerably shorter lift-duration.
Hopeful-Cheers,
-Bob
" I have a feeling I must be missing something you are trying to tell me. "
____ Well actually I wasn't trying to TELL you something, rather I was trying to find-out whatever it is you actually have to work with there...
Since it seems you're sure you have nothing at all as a AAU, then I'm wondering if that which you do have is even a stock setup !? _ Cuz normally the body of an AAU is what's used to hold the points-cam while the AAU-body is held-down (by the screw) to it's drive-shaft.
__ Bill has nicely provided a very-good post which well explains pretty-much everything on this, (and in a considerably better fashion than I-myself would've done here), thus saving me from having to get any more detailed about it !!
So now hopefully you -(Jim) can clear us up on what-all is different in your case. - (A pic or two would be nice!)
__ Your Duke may be an early-65, but still, I'd expect it to be new enough to have come with a working AAU.
Have you checked your motor-number against the number-listings which list the recommended static-timing covering your particular issued-model ?
" he admitted that the bike would not rev past 6K for him either. "
____ At this point it seems likely that someone in the past swapped-out some original parts.
And it seems that you ought to source for yourself a working stock-type AAU, (as Bill has).
__ Did it not include it's 29mm SSI, either, (when you first got this Duke) ?
____ As a side-note, the pic that Bill has posted showing an AAU mounted down-inside it's cavity (behind where the points-plate is normally mounted), shows a points-cam with the longer duration that's intended for the battery-type ignition-system.
So YOURS ought look pretty-much the same except for the cam's lobe ought appear with a considerably shorter lift-duration.
Hopeful-Cheers,
-Bob
PLEASE NOTE... If this-post is not-yet signed-off with '-Bob', then I'm still in the process of completing it,, and if not also included with 'DCT' near bottom as well, then I may edit this post's wording at a later time. - Dct.Bob
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Re: Cure for an ankle buster?
So YOURS ought look pretty-much the same except for the cam's lobe ought appear with a considerably shorter lift-duration.
There's a pic of it here in the 5th post (the one with the points plate), it's the short lift-duration cam...
Bill
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Re: Cure for an ankle buster?
Sounds to me like Jim has the solid point cam. This is simply a hollow shaft with notches on one end that engage the flats on the ignition spindle and a point cam machined on the other end. This slides on the ignition spindle and is held in place by the screw that threads into the end if the ignition spindle. Doesn’t rotate on the spindle at all. The point cam is indexed to provide correct timing within the adjustment available via the slots in the point plate with correct point gap. Achieves the same effect as a welded AAU but without all the added (and wasted) hardware that makes up an AAU. This is a cataloged Ducati part. Seems to me they were specified for the Diana Mk3 or Mk3 but I don’t have my parts book handy (might be in the parts catalog on this site but when I enlarge those liveshare images they just blur). I have an 88xxx series motor that was in a ’65 chassis and I think it had the solid point cam. I’ve also seen them in the later Mk3’s. I always figured the welded AAU’s were some genius deciding that locked advance was going to give better performance and tack welded the unit solid. Was the welded AAU a factory part on some bikes? Matt
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Fixed-advance Points-cam Units
" Sounds to me like Jim has the solid point cam. This is simply a hollow shaft with notches on one end that engage the flats on the ignition spindle and a point cam machined on the other end.
Seems to me they were specified for the Diana Mk3 or Mk3 "
____ I've seen that simple part but only once or twice on early pre-1963 4-speed 250-Motocross models,, and it seems that once Ducati began employing the AC-type of AAU (for their magneto-type ign.system), they would afterwords never revert-back to the fixed-advance setup, (unless there became an extended parts-shortage for that unique part).
" I’ve also seen them in the later Mk3’s. I always figured the welded AAU’s were some genius deciding that locked advance was going to give better performance and tack welded the unit solid. Was the welded AAU a factory part on some bikes? "
____ That's always been something which I also have long wondered about !
At first, in the late '60s, (after finding a fair number of the braise-welded 18-degree AAUs), I then thought perhaps that there had been a popular cycle-mag tech-report article (which I had somehow missed), that must've claimed that lower-end power would be usefully increase by completing such a mod,, but after finding quite a few more of such units (by the '80s), all done-up the same way, I then-later came to highly suspect that the D.factory was the actual source of those (wasted!) AAUs (for some strange & unknown reason). _ But still not sure though !
__ Once thinking of them as ruined junk, I had tossed at least a half-dozen of them into the metal-scrap heap.
Dukaddy-DUKEs,
-Bob
Seems to me they were specified for the Diana Mk3 or Mk3 "
____ I've seen that simple part but only once or twice on early pre-1963 4-speed 250-Motocross models,, and it seems that once Ducati began employing the AC-type of AAU (for their magneto-type ign.system), they would afterwords never revert-back to the fixed-advance setup, (unless there became an extended parts-shortage for that unique part).
" I’ve also seen them in the later Mk3’s. I always figured the welded AAU’s were some genius deciding that locked advance was going to give better performance and tack welded the unit solid. Was the welded AAU a factory part on some bikes? "
____ That's always been something which I also have long wondered about !
At first, in the late '60s, (after finding a fair number of the braise-welded 18-degree AAUs), I then thought perhaps that there had been a popular cycle-mag tech-report article (which I had somehow missed), that must've claimed that lower-end power would be usefully increase by completing such a mod,, but after finding quite a few more of such units (by the '80s), all done-up the same way, I then-later came to highly suspect that the D.factory was the actual source of those (wasted!) AAUs (for some strange & unknown reason). _ But still not sure though !
__ Once thinking of them as ruined junk, I had tossed at least a half-dozen of them into the metal-scrap heap.
Dukaddy-DUKEs,
-Bob
PLEASE NOTE... If this-post is not-yet signed-off with '-Bob', then I'm still in the process of completing it,, and if not also included with 'DCT' near bottom as well, then I may edit this post's wording at a later time. - Dct.Bob
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Re: Cure for an ankle buster?
I definitely have the solid point cam.
I was too anxious to wait until tomorrow - I buttoned everything up and went for a quick ride tonight.
The engine started rather easily - no ankle-breaking kick back.
Revved the unloaded engine on the driveway and saw 8000 rpm. Looks promising.
I took the bike out and... Oh Crap! It's sputtering at 6000 rpm again. Of course the engine is now under load too.
Twice around the block. 6K limit in all gears.
Back in the driveway I pulled the spark plug and it was sooty. I would call it dry soot, not wet. I don't know if that's a clue or not.
Possibly it got to 8K rpm upon initial start-up because the plug was clean - and the soot formed quickly and that suppressed the RPM.
I am now at a 180 main jet (down from 190 but remember the previous owner admitted that the bike was unable to get over 6K when he had it.)
I have the needle at the middle. I could drop the needle but if the consensus is that I need to drop the jet size I will have to order more jets and wait for them.
I was too anxious to wait until tomorrow - I buttoned everything up and went for a quick ride tonight.
The engine started rather easily - no ankle-breaking kick back.
Revved the unloaded engine on the driveway and saw 8000 rpm. Looks promising.
I took the bike out and... Oh Crap! It's sputtering at 6000 rpm again. Of course the engine is now under load too.
Twice around the block. 6K limit in all gears.
Back in the driveway I pulled the spark plug and it was sooty. I would call it dry soot, not wet. I don't know if that's a clue or not.
Possibly it got to 8K rpm upon initial start-up because the plug was clean - and the soot formed quickly and that suppressed the RPM.
I am now at a 180 main jet (down from 190 but remember the previous owner admitted that the bike was unable to get over 6K when he had it.)
I have the needle at the middle. I could drop the needle but if the consensus is that I need to drop the jet size I will have to order more jets and wait for them.
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- Joined: Sun Nov 01, 2009 10:53 am
- Location: Near SE side of Lake Michigan
Re: Cure for an ankle buster?
____ Isn't this post in the wrong thread ?JimF wrote:I definitely have the solid point cam.
I was too anxious to wait until tomorrow - I buttoned everything up and went for a quick ride tonight.
The engine started rather easily - no ankle-breaking kick back.
Revved the unloaded engine on the driveway and saw 8000 rpm. Looks promising.
I took the bike out and... Oh Crap! It's sputtering at 6000 rpm again. Of course the engine is now under load too.
Twice around the block. 6K limit in all gears.
Back in the driveway I pulled the spark plug and it was sooty. I would call it dry soot, not wet. I don't know if that's a clue or not.
Possibly it got to 8K rpm upon initial start-up because the plug was clean - and the soot formed quickly and that suppressed the RPM.
I am now at a 180 main jet (down from 190 but remember the previous owner admitted that the bike was unable to get over 6K when he had it.)
I have the needle at the middle. I could drop the needle but if the consensus is that I need to drop the jet size I will have to order more jets and wait for them.
____ Anyhow, what about the ign.timing, do you have it set about 40-degrees BTDC yet ?
Hopeful-Cheers,
-Bob
PLEASE NOTE... If this-post is not-yet signed-off with '-Bob', then I'm still in the process of completing it,, and if not also included with 'DCT' near bottom as well, then I may edit this post's wording at a later time. - Dct.Bob
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