'72 XS 650 Auto Advance Issue

[IM SYKO]

Hello all. I just picked up a '72 XS650 and the auto advance is spinning around. Unfortunately I couldn't find a manual on PDF so waiting for printed version to get here.
The plate with the red line is spinning around and I assume there is a locking pin or something that secures its orientation. Before I started ripping into it I thought I would ask. The next question I have is of I remove the lock nut and slide the plate of will it upset anything internally?
Appreciate in and all input. Thanks for looking!

 

[JOHNDADDY]

There is a pin that locates the base plate. And yes you can remove the unit with out damage. It's a small pin may be an 1/8" X 3/16". Take a look in your cover, it might still be there, it shouldn't be able to escape with the cover on.

 

[IM SYKO]

There is a pin that locates the base plate. And yes you can remove the unit with out damage. It's a small pin may be an 1/8" X 3/16". Take a look in your cover, it might still be there, it shouldn't be able to escape with the cover on.

Got it. I will double check. Thanks for responding!

 

[JOHNDADDY]

While the advance weight are off do not spin the shaft or you can put your timing out 180°

 

[IM SYKO]

This is what I found. I assume that the pin by the red arrow has worked its way out and needs to go back in for it to line up the plate? The pin with the green arrow has me stumped.

 

[IM SYKO]

While the advance weight are off do not spin the shaft or you can put your timing out 180°

Got it. I am going to have to reset everything from the chain tension to valves etc.

 

[5twins]

The notched ring that holds the advance unit backing plate on has a raised "lip" around it's I.D. and that should face out .....

In your pic, it looks like yours may have been installed backwards ("lip" facing in). That may not tighten down properly and hold the backing plate in well enough.

That pin sticking out of the backing plate is a retainer to stop the locating pin from falling out .....

 

[IM SYKO]

The notched ring that holds the advance unit backing plate on has a raised "lip" around it's I.D. and that should face out .....

View attachment 249800

In your pic, it looks like yours may have been installed backwards ("lip" facing in). That may not tighten down properly and hold the backing plate in well enough.

That pin sticking out of the backing plate is a retainer to stop the locating pin from falling out .....

View attachment 249801

Got ya. They guy I got it from had a somebody repair it and it made it a few miles and quit so assembled backwards doesn't surprise me. the retaining ring was loose when i took it apart

 

[5twins]

While you have it apart, you'll also want to service the advance rod (clean and grease). It needs to be kept lubed to function properly (turn easily and smoothly). The outer bushing in each end of the cam should have grooves cut in the I.D. You want to pack them with grease. The factory shop manual recommends a grease with moly in it .....

Although it's not mentioned in any of the manuals, this should be considered a maintenance item. You don't have to do it very often, maybe every 5 years or so, but it needs doing. Most haven't been serviced since they left the factory and are long over-due.

 

[IM SYKO]

The notched ring that holds the advance unit backing plate on has a raised "lip" around it's I.D. and that should face out .....

View attachment 249800

In your pic, it looks like yours may have been installed backwards ("lip" facing in). That may not tighten down properly and hold the backing plate in well enough.

That pin sticking out of the backing plate is a retainer to stop the locating pin from falling out .....

View attachment 249801

Bingo! You nailed it. Now the pin in my picture with the red arrow is that correct or should it be flush?

 

[5twins]

It looks correct. It has to stick out for the slot on the advance unit to lock onto it.

 

[IM SYKO]

It looks correct. It has to stick out for the slot on the advance unit to lock onto it.

Got ya. I'll clean this up lube everything and see what we end up with. Appreciate the help!

 

[JOHNDADDY]

Glad it wasn't blown out. Over revving the engine will peel that locating flange back like a tuna fish can key. No Tach or Speedo on mine.

 

[IM SYKO]

Glad it wasn't blown out. Over revving the engine will peel that locating flange back like a tuna fish can key. No Tach or Speedo on mine.

 

[IM SYKO]

Got it back together and it fired right up. Thanks for all the help. No tach or speedo on this either.