3BOS4U1 in Bosch 2-piece points distributor. Example 1:

Example done by a customer: Remove the distributors base plate from the distributor. Grind or file of the 'bump' of the Hot-Spark base plate. Drill the 4mm screw hole of the Hot-Spark base plate to 8mm (8,5mm), so it'll fit exactly over the pivot pin base. Next drill out the (right) threaded hole of the Hot-Spark base plate so that a 3mm bolt will fit through it. Next re-attach the Hot-Spark ignition module to the Hot-Spark base plate with the left Allen head screw. Then test fit the Hot-Spark on the distributor plate. The 8mm hole can now be used for alignment on the left side. Install the magnet sleeve onto the distributor shaft to help align. Now mark where the hole on the right side needs to be, and drill a 3mm hole in the distributor plate. The Hot-Spark unit can now be mounted on the distributor plate using a 3mm screw, using a lock washher and nut. Works great!

3BOS4U1 in Bosch 2-piece points distributor. Example 2:

Example done by a customer: Take the distributors base plate out of the distributor. Drill 2 new holes in the breaker plate for the peg and screw, and use a Dremel tool of file to grind off the 'bump' on the breaker plate. Make a M4 thread on the new hole. Then fit the 3BOS4U1 kit straight on. This way I didn't have to modify the Hot-Spark ignition kit at all. Works perfectly!

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3BOS4U1 in Bosch 2-piece points distributor. Example 3:

Example done by a customer: File off the 'bump' on the bottom of the Hot-Spark base plate. Drill out the 4mm hole in the Hot-Spark base plate to 8mm, so it fits exactly over the pivot pin base. Then drill out the right hand threaded 3mm hole of the Hot-Spark base plate to 4mm. Next also drill out the right hand 3mm hole of the Hot-Spark ignition unit to 4mm. Now the 8mm hole is used for centering the base plate at one end. The other end is attached to the distributors breaker plate using a (small headed) 4mm bolt that screws into the original threaded hole where the contact breakers used to be attached, while holding down one end of the ignition unit and the hot-spark base plate. Works like a charm! (sorry for the blury pictures)

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