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sprocket/Rotor Spacer

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I have a spacer which according to ANIL fits between the driver engine sprocket and armature rotor. Can anyone confirm this is correct? There is no mention about this spacer in my Haynes 650cc workshop manual.

I have what might be the spacer but it will not pass over the sprocket's woodruff key, since I have not yet removed the woodruff key I am sure the 'spacer' was NOT fitted when I took the primary side apart to fit my side stand.

If there should be a spacer does anyone know it 's dimensions so I can possibly identify what I have in my box - sorry if this is a long shot?

Anyway thanks for any help, again.

 

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Roger, It depends on which alternator set you have fitted.  With the smaller o/d rotor (70mm) the depth of it is wider so no spacer is required.  With the higher output set (RM18/19) the rotor has a larger o/d (74mm) but the depth is thinner so a spacer was fitted.  Cheers, Howard 

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Roger.....I am guessing that your bike is a 650, so probably post 1960. In which case, as Howard says, if it has the later RM 21 Alternator fitted then the only washer/shim needed is a nice chunky spacer to fill the gap between the thread on the end of the crankshaft and the rotor. There should also be a large  spring  (or star) washer to help keep everything in position. A missing washer can lead to the rotor moving around and making a sound (plus vibes) similar to the bottom end failing.

See attachment for the position of parts on my 99. The washer is getting on for 2mm thick with a fully compressed heavy duty spring washer between it and the nut.

With the thicker RM19 rotor there is no real need for the spacer but also no harm in it being there. The only time you might need a shim/spacer on the inside of the rotor is in trying to get the rotor and stator centres to line up. This is generally not worth the time and effort.

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Well thanks for your words I had better get my measuring stick out.

Regards Roger

Hi Howard and Philip, the rotor I have has a diameter of 70mm and length or depth of about 40mm. This is a Lucas  rotor with number 466177. Since it is 70mm then it does not require a spacer between rotor and sprocket.

The stator has the numbers 47127    B and 48   72 if that means anything.

So thanks again I will rebuild without a spacer.

 

 

 

 


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