The problem with the old ignition sounded like a bad ignition cap. I bet if you look into the cap of the old ignition the silicone insulator will be blackened or otherwise discolored. If the cap has ever made contact with the ground or anything, it is always a good idea to replace it. Now retired, you might disassemble the old cap and inspect it. I bet you find a problem in there and if so, you could replace the cap for about $10 and perhaps have a good spare ignition for the future. Yes, certainly the ignition box itself could be the problem but my bet is the cap.

Here is a pic of the original cap. It was brand when started and only had 10-15 minutes run time when it started missing as in the video in my original post.

Well then it sounds and looks like you had a bum ignition. No argument from me. Just be aware that caps can cause all sorts of problems and they are often overlooked as a source of problems.

Originally Posted by kimchiyuk

New ignition ...problem solved!

https://youtu.be/0hhQI4UcI64

Nice ,glad you got it running right!

I have a saito ignition that never quite work right off the bat.. do you think is worth disassembling it and keep the cap?

I think I would send the O.S. people a letter and a link to your videos.

Originally Posted by Swampflier

I have a saito ignition that never quite work right off the bat.. do you think is worth disassembling it and keep the cap?

I'd never reuse a cap. They are economical to buy new and old ones are prone to failure.

Thanks Truckracer... in the trash it goes...
Any preferences for replacement caps?

Caps available from CH Ignitions, Valley View RC, Tower Hobbies under DLE parts, RC Extreme Power just to name a few. About $10.

My O.S.33 suddenly developed a condition where it just refuses to rev up. It starts easily and idles fine but will not throttle up past about 1/3 throttle. It bogs and dies. I have tried everything. Carb kit, spark plug, etc. Just can't troubleshoot it. I am finally sending it to Horizon. We'll see if it's the ignition.