ET: Engine (Twin) Dynamo Alignment

[Rob H]

I am having a problem aligning the dynamo sprocket with primary drive chain. The issue seems to be that the PD16 dynamo boss does not seem to go far enough onto the taper even when tightened with the nut.

The result being the nut can not be fully threaded and the boss protrudes to far into the primary drive for the dynamo drive sprocket to line up with the centre of the primary drive chain.

Bike is an early B with a 3.1/2" miller dynamo.

Struggling to find a solution, I am looking to gain about 1/16 - 1/8" to be able to line up the drive sprocket.

 

[fogrider]

In absence of any other advice coming forth, it looks as though the amount you need to gain could be simply turned off the boss - it looks quite thick ?

But why is there a mismatch ? have you changed some components ?

 

[Rob H]

I have not changed components, it went to the refurbisher with the boss on and came back with it. I assume it is still the same boss but cannot be sure.

 

[ernie]

Can’t you push the dynamo out a bit? And there is a special shouldered nut.

 

[Rob H]

Can’t you push the dynamo out a bit? And there is a special shouldered nut.

Yes can move the dynamo out a bit but that would leave a large gap between the face of the dynamo and crankcase.

I have studied and measured up the solution seems to be as suggested to machine 1.8mm of the face of the boss

 

[timetraveller]

Why not just make up a thick 'O' ring to fill up the gap. With the 'Walkernators' for twins I provide a length of either silicon rubber tube or soft nitrile 'O' section material which can be cut to length, glued into a continuous ring and then compressed between the back of the crankcase and the front face of the dynamo replacement. The soft nitrile material is for those who use normal oil in their primary drives and the silicon rubber for those who use ATF or similar.