Tom,

I have done quite a few of the OS46AX engines. I have always done them per the manual for the exact same reason you mentioned in regards to the warranty claim if needed.

Now, I personally have never had a problem with the engines and even though I no longer have any of them, I do get to see them run on a weekly basis as I sold everyone of them along with the plane that they were mounted in to other club members.

Most all of them are now over 200 flights using the exact same fuel I broke them in on (Byron 15/20 Castor/Syn blend) and all of them are on the same glow plug as they started life with as far as I know.

The only adjustments they ever needed after getting then properly tuned on both the low speed and high speed needles was the odd click here and there for the high speed which was more weather dependent than anything else.

I every case, if the engine was cold, open the throttle, 3 or 4 flips of the prop with my finger over the carb to get fuel up, close the throttle to normal idle attach the glow driver and bump it with the starter and off she went. If the engine was recently run, no priming, just attach the glow driver, hit it will the starter.

I have now used the same breakin method for my OS160FX's and they have all responded the same way with the big difference being I do not use a starter. I prime it, attach the glow driver and bump the spinner clockwise against compression which then kicks the engine the other way (counterclockwise) and off we go. On occasion I bump it too hard and it runs backwards but I just close the throttle completely and try again.

Maybe I was just really lucky on all of them.