AAU Fixing Screw m4x10

[tobydmv]

Anyone have a pic of the auto advance screw and washer? My screw rotted out a long time ago and was replaced with a socket head allen bolt since that's all the hardware store had. I'm trying to track down the source of some random kick backs that kind of come and go as they please. I'm wondering if the AAU might be getting stuck in full advance due to the allen bolt i'm using or maybe the springs arent retracting it, IDK at this point. If you have any other ideas please let me know. It seems to be really bad some days and other days not at all. I probably need to reset the timing again.

[Duccout]

I'm not sure that can happen - the AAU cam on mine has a lot of end float and would not be gripped by a washer. These parts are now so old that I would guess that most AAU are really worn.

[tobydmv]

I'm not sure that can happen - the AAU cam on mine has a lot of end float and would not be gripped by a washer. These parts are now so old that I would guess that most AAU are really worn.

Yeah I agree, I just took a really close look at the old AAU and the cam lobe is recessed from the advance shaft. I dont think the fixing bolt or washer can capture it unless the washer is conical and mine isnt. My AAU also seems to be free to advance so i'll check the timing again and go from there.

[ducwiz]

Have you looked into a parts catalog, especially for your bike? In most of them the dimensions and types of screws and shims are given.

Hans

[tobydmv]

Have you looked into a parts catalog, especially for your bike? In most of them the dimensions and types of screws and shims are given.

Hans

Yes sir, thats where I pulled the m4x10 and verified that the driven gear and shaft parts are universal across models but the AAU is not. The scrambler and monza have different aau. My bike started as a scrambler and was converted to monza DC ignition. I've been trying to get it right ever since. Thanks Hans!

[Jordan]

Don't dismiss the AAU as being probably worn out.
This part of the Ducati singles that is well designed and generously proportioned.
I have rarely seen one that is worn out, just some dead ones that had rusted due to poor storage.
It is easy enough to check for smooth operation. After disassembly and cleaning, lubricate and reassemble to the bike.
It should be easy to twist the cam with fingers, and letting it go will allow it to spring back.
A sloppy action could be due to worn springs.
A minor issue with the AAU is that it can be installed 180 degrees from correct position, easy to put right.

A battery-less Ducati "points" single uses an AAU with a reduced ability to retard, so it is inherently more prone to kick back if not given a swift kick.