1QwkSport2.5r

Your system will not work in a bump start engine as I expected. For the OPs engine, he wanted to convert from bump start to pullstart or rotostart. That means they would need the crankshaft that picture number two would drive (extended crankpin needed and not present in a bump start engine), then they would need the backplate (present only on pullstart/rotostart engines) in picture number one to hold the starter shaft from page two. So your system will not work on a bump start engine.

The problem with OS engines is that parts are expensive and on older engines very hard to find due to poor distribution. Those two parts could equal half the cost of a whole new engine easily. Your system (although very neat) would work on an existing pullstart engine at the expense of parasitic power losses due to the engine driving the starter/charger system. Then there's the expense of the system. What does the system cost? I am guessing it would need to be shipped from China? Does the system come with the modified backplate? If not, how would the average modeler without a lathe or milling machine modify the pullstart backplate to fit the bearings? Is the starter shaft only bushed with the bronze bushing or is it sealed with an o-ring too? What modifications were done exactly? What safeguards are put into the system to prevent oil from getting into the starting unit from the backplate? Can you link us to the installation instructions or are there not any?