Need help with Mechanical advanve R&R

[Slimbob]

Hello,
My Haynes manual does not cover this action.

I'm trying to replace the ignitions mechanical advance plate assy.

I removed the weights and springs and tried to back the star nut off but it seems to bind when I get it off so far. It will not come all the way off the unit. The whole shaft starts to turn.

Can someone please give step by step on how to R&R the whole assy?

Thanks,
Slimbob

 

[XSLeo]

On the few I have done you don't need to remove the weights, just turn the nut and pull the advancer out as the nut loosens.
Did you remove the advance rod before you tried the advancer?
I can't think of anything it can bind on.
Maybe other will have more helpful advice.
Leo

 

[5twins]

Once the star nut or slotted ring is loose, it should screw right off. I would examine the threads on the end of the cam. Maybe they're damaged or clogged with rust or dirt. A little work with a thread file may help.

 

[Slimbob]

Ok, here is the answer.

XSLeo, you had the fix when you mentioned removing the shaft first.

The star nut would not come off over the ATU (Automatic Timing unit) adapter. This is the piece that the weights small arms ride in. I tried to loosen the nut on the end of the ATU shaft but it broke loose on the points (left) side of the shaft. I was then able to remove the points mounting plate and points, as a unit and pull the whole shaft out the right side.

Likewise, I had to place the new star nut and advance ATU on the shaft before reinstalling the shaft through to the points side.

I didn't care about the points mounting plate because I am installing the Pamco electronic ignition at the same time.

The advance weights seem to be working properly now. I can pull them out and they return to their normal position easily.

Now I can consentrate on installing the new Pamco ignition.

Thanks for your suggestion. Easing the plate out with the nut did allow me to get the nut off the threads but it would not come all the way off without removing the shaft.

Thaks again,
Slimbob