OS never dissapoint specially the SF series, in my opinion the golden era of 2 stroke OS engines.

No matter what oil is in the fuel, the OS engines with piston ring always run well.

Nice run. I suspect a single flip would get it started, but I know you have issues after so many years of hand starting. Great engine. I’m breaking in a K&B 65 Sportster. After around 30-40 minutes it is only getting close to your OS initial run. The SF are the the best series.

Nice I picked one up about a month ago in a package deal 100 bucks for the engine and plane kit and all to complete it I've been running os in my planes for years and have always been pleased with them great to see that you're still enjoying running rc engines as a hobby keep the videos coming 👍

Nice steady first run! funny I have just come in from running a OS 25 SF flick started and ran spot on! OS!! say no more, the SF range have always been top of my list, I have three 25s WHY? can't stop running the things from the age of 10 now 65!!!

Another well manufactured engine. It should be another great acquisition of yours.

very good run. ,its an OS. i prefer the ring engines. i still have a new,61,fsr,ringed motor,never started. maybe, one of these days.

Got one myself, also new in box. Will keep that way for a while. Nice video as always, enjoy watching 🙂

Thanks David! Sounds really good.

Hi David. I came across your channel quite by accident and wish i had found it years ago. Some of your engine videos take me back to the 50s 60s in England when i was a lad just getting into model making. my first model was a Cox plastic control line plane with a cox Pee Wee motor. then i graduated to making my own Balsa and tissue paper models powered by small diesel engines, we would make our own fuel ( castor oil, ether and paraffin <kerosene>) but i digress. I have been looking for about 5 years for a long ago discontinued OS four stroke engine which was for model cars. OS FS 40S-CX and after finding your channel i thought this guy may have one, know someone who has one or can point me in the right direction to find one. I would have liked to have emailed you direct but the 'About" section in your profile no longer exists so there was no way to find your email address. Accept my apologies if i have been waffling on but my hopes have been raised just by finding your channel.

Curious David, I notice times you put the glow ignitor back on after the engine is started? Great engine and run. Thanks

Hello David, big fan here, I recently bought a brand new bully 1.20 LS from an old timer, there are no videos on tuning the carb and internal pump and very few info in forums, is it possible to feature that engine on your channel somehow ?