1950's Bosch Pendulum Starter in motion

Unlike other electric starters, the Bosch pendulum starter of the '50s rocks the engine's crankshaft back and forth rather than rotate it. A somewhat complex system of contact switches and a solenoid makes sure that the plug fires multiple times during the starting attempt, but only while the engine is turning in the forward direction.

In this video, the flywheel is seen changing direction back and forth - it's not spinning.

The idea behind this starter design is that it takes much less electrical power to just rock the crankshaft than it would to spin it over past the combustion chamber's compression. By rocking it back and forth and generating multiple ignition sparks only while the engine is moving forward, the starter simply has to fire the engine enough to "bump" it past the compression point, where the engine will generate enough momentum to start rotating on it's own and begin running.

Category:

Autos & Vehicles

Tags:

• vintage
• motorcycle
• scooter
• maicoletta
• oddscoot

[ossamotocross]

So it rocks the engine back and forth? I heard these systems can be a bit temperamental - True?

[seat850c]

A bit. Mostly they're just so wierd that something else acts up you end assuming it's the odd starter, start messing with it and then get it all out of adjustment.

[seat850c]

Absolutely. It works out 1 out of 5 times at best. I get my excercise push starting the bike as it has no kick starter as a fall-back!

[injunscout]

Very interesting, but what was the point? The ability to use a smaller battery?

Thanks for posting.

[seat850c]

That's a good question. The assumption is packaging, as the engine on this scooter has no real facility for an electric starter, and this system allows using the dynamo that's already there as the starter.

[cd1306]

ho why one pendulun motor?

[ossamotocross]

I have several vintage Maico motocross bikes myself

and love anything Maico in general - wouldnt mind an electric start on my 490 somedays - LOL!