The 9.17 cc (0.56 cuin.) O.S. K6 spark ignition engine of 1986 was a faithful replica of the 1940 O.S. Type 6 sparkie which had been one of the more successful pre-WW2 models from this famous manufacturer. 2,000 examples were manufactured in 1986 to mark company founder Shigeo Ogawa's first 50 years as a model engine manufacturer.

Althoigh it was extremely faithful to the original in design terms, the K6 replica did incorporate a few detail improvements which made it if anything a better engine than its Type 6 progenitor. For one thing, it used high-quality investment castings in place of the sand-castings used in the origial 1940 products.

These engines were produced with the very clear expectation that they would be purchased for the most part by collectors, with relatively few examples actually seeing service in a model. This proved to be an accurate assessment, the result being that the majority of the 2,000 engines still survive today in new or near-new condition. They do run very well indeed if any owner cares to give them a try.

A full review and test of the O.S. K6 replica appears elsewhere on this website.