Saw this on the home page and decided to give it a read.
As a boater we push our stuff to the limits and run nitro content that would scare most pilots!
For me I don not get any life out of OS plugs, tried a few heat ranges and all of them last about a run. If they last the coil is really messed up. They just seem too delicate. Maybe the wire is a smaller gauge, I honestly don't know the reason.
Why a cheaper plug like the McCoy lasts a day or more of running and a twice as expensive OS plug fails every run is beyond me, have the same issue with HPI plugs, I was stuck one day and pulled a 30 year old fox plug out of a 35 cl engine and got a days running, the plug is still fine and back in the CL engine.
And yes after 25 years of boating I know how to tune a hot boat engine. Including how to properly shim a head to adjust for nitro content etc.
My real world testing in a very harsh environment has proven as far as I am concerned is that OS plugs really suck in a marine application! This is across a number of brands of engine and sizes, all the way from a HPI .15 air cooled buggy motor in a small outrigger to big OPS .67s in deep vees, O.S .46 marine, K&B 3.5 and 7.5 marine inboard and a outboard 3.5, Nova Rossi 3 port .12 marine.
A wide variety of engines and no luck with OS plugs. I have no brand favorite and try out a few brands on each new engine until I find what it likes. For some reason that always seems to be a cheap McCoy! depending on the size of the engine and nitro content either medium or hot.
I run 30-50% nitro depending on the size of the engine. 18% oil with 3% being castor.
Flame away, thems the facts as far as I'm concerned, many years of real world testing there in a variety of engines in an environment way more brutal than most plane engines could live up to. I said MOST not all!
No idea how the work for a sport flyer but in my application they are a waste of money.