I am in the process of trying to fit the Tri Spark Classic Twin Ignition on my 75' Mark III and am having difficulty removing the auto advance unit. I do not have the service tool so they state to thread in a correct size bolt and gently tapping it until it falls off the taper. We have tried tapping around on the unit to loosen it but to no avail. Does anyone know the correct size bolt to fit in there or any other way to do this. Thanks in advance for any response as your advice is greatly appreciated. By the way it is the Lucas Rita Unit that is being removed.

porterg wrote:By the way it is the Lucas Rita Unit that is being removed.

As I understand it, it is the Lucas pickup "reluctor" that you are trying to remove?

You will probably find the reluctor extractor thread is metric M8? The original AAU ext. thread would be 5/16" UNF, so the Norton service tool (a 5/16" x 3-3/16" fully threaded bolt with the first 2-9/16" machined down to 0.20" -would be no use.

The reluctor won't self extract, no matter how far in you try to screw in the extractor bolt unless you insert a short piece of rod into the reluctor first, so that the extractor bolt has something to push against once it has been screwed in a few turns?
In any case, screwing the M8 bolt of approximately 2"/50mm in length into the reluctor by a few turns of thread and then lightly tapping the bolt head UP-DOWN-LEFT-RIGHT a few times, should be enough to loosen the reluctor from its taper?

Look in the Tri Spark package. Mine came with the bolt.

L.A.B., it is called the Reluctor, I did a search and came up with a layout for a Rita. I went to the hardware and purchased an 8M bolt, it will only turn in about 1/2 turn and when tapped gently it moves quite a bit and I do not want to bugger it up. I am trying to proceed cautiously becase this is the first time I have had the points cover off an engine. Any other thougths or ideas would be appreciated.

Cookie, you were right, the bolt supplied by Tri Spark is an 8M and 2 1/4 inches long and I originally thought it was used to secure the stator. Thanks for the reply.

porterg wrote:I went to the hardware and purchased an 8M bolt, it will only turn in about 1/2 turn and when tapped gently it moves quite a bit and I do not want to bugger it up.

Sorry the M8 didn't fit.

Try a 5/16" UNF and see if that fits?

M8 certainly fits my reluctor threads better than a 5/16" UNF, however after further research, a 5/16"-24 UNF thread could be the right one for some RITA reluctors?

Tri Spark does say that sometimes they can be so tight as to require the factory type puller.
I think mine came with three bolts, two for the possibilities on center bolts and perhaps the last as a puller bolt. It's a small company and perhaps once ina while there are variations in the kit.

Wouldn't the bolt for the reluctor be a 1/4-26? Unless it is a MegaCycle cam who threads their cams 1/4-28.

Ron L wrote:Wouldn't the bolt for the reluctor be a 1/4-26? Unless it is a MegaCycle cam who threads their cams 1/4-28.

The Commando reluctor fixing bolt would normally be 1/4"-26 (BSF) same as for the standard AAU fixing bolt, however the extractor bolt that that is used to pull it off the cam taper obviously must be a larger diameter, as it screws into the internal reluctor threads and not the camshaft.

I didn't realize the reluctor was internally threaded until this discussion! I checked a couple I had in the shop and they are not 5/16-24 or 5/16-18. An M8 X 1.25 also does not thread. I tried a 5/16-26 tap and it doesn't seem to thread either! Now I'm curious what thread form that is. The RITA instruction sheets do not mention any puller bolt or thread size.

I have always had success using a long 1/4 inch bolt slipped inside the reluctor (or AAU with points) and tapping sideways in all directions until the taper releases.

Ron L wrote:I checked a couple I had in the shop and they are not 5/16-24 or 5/16-18. An M8 X 1.25 also does not thread. I tried a 5/16-26 tap and it doesn't seem to thread either! Now I'm curious what thread form that is. The RITA instruction sheets do not mention any puller bolt or thread size.

The only logical alternative would be 5/16 -22 BSF, then?

[Edit] I've just tried a 5/16 BSF screw, and it could be the right thread, as it does screw in about 6 or 7 turns until it tightens up, but so does the M8 as the reluctor threads are bit chewed up inside, maybe from myself and previous owners using metric or UNF extractor bolts?

Thanks for all the feedback. I just received a note back from British Cycle Supply for the status of an extractor, they have one at a price of 28.99. I am certain I can fit this ignition and the Podtronics 200W Regulator myself if I can get this piece out. I am really concerned about buggering the piece as I would have to drive 220 miles round trip to Atlanta or Birmingham to a tech and leave the bike and go back so the price of the tool is about half the gas involved. I also get the self satisfaction of doing it myself. I will post as things progress, thanks again fellows.

Sorry again that the 8mm didn't fit.

I suggest you try Ron's suggestion of fitting a long 1/4" bolt inside the reluctor and then tapping the head each way as described?
As the reluctor is only held by the camshaft taper and a few taps on the bolt head should shock it loose?

Just as a note of caution, don't whack it too hard sideways as the camshaft nose surrounding the internal taper is not all that thick.

It shouldn't be a problem with an older standard cam which I assume you've got but cold-chilled PW3s can and do shatter there if abused so it may be that the newer Andover cast iron cams are vulnerable too ?

I've seen the results of somebody trying to do a hasty race paddock reluctor change on a PW3. Not nice !

The tool is attached and after 30 minutes of judicious slide hammering I only have 1.5mm of movement. This doesn't strike me as correct, any suggestions?

I'm sure you tapped the tool sideways?