From:Steve Marks
Subject:RE: Simms Magneto SR4X Date:Wed Mar 17 11:14:20 2010
Response to:2858
Hi Fritz
The correct Simms magneto is a C4 but anything which is dimensionally correct and the correct rotation will work OK. I don't have any dimensions for an SR4X to hand but the C4 has four fixing holes in a square at 50mm centres. The centre height of the drive shaft is 45mm above the base. The SR4X has large brass flaps over the oil holes which would get in the way of the dynamo saddle. These could be replaced by a sheet metal flap as on the C4. (If the mag is overhauled correctly with grease filled bearings, you don't need to oil them anymore anyway). Finally, make sure that the direction of rotation is correct - clockwise on a Henderson. This is always referred to as seen from the DRIVE end. So the points end will go anticlockwise. The points are different for the two rotation directions - the heel of the points should be 'pulled' and not 'pushed' as the armature rotates. Internal timing can be changed to reverse rotation but you do need to have the correct points!
At risk of being accused (correctly) of blatant advertising, some of you guys may be interested in my website -

Is a Simms SR4X magento suitable for my 1925 henerson?