ORIGINAL: Khizer
Hi Guys,
I have read a lot of posts that says during running-in don`t 4-cycle 2- Stroke ABC/ ABN Engines.
Well this is not true. I ve 36 OS engines all broken-in in the 4-stroke regimes and all running well. I never had any cylinder peeling either.
4-stroking an ABC engine during break in is the worst thing you can do to it. Your confused. Also--4-stroking an ABC during break in is NOT what leads to cylinder peeling. The cylinder peeling is from leaning the needles out too much and getting the darn thing too hot.
I also wrote a letter to OS engines Japan back in 2001 asking about this and they confirmed that peeling of liner is not because of running in 4-cycle regime but due to lack of lubrication caused by synthetic fuel and running engines in dusty environments e.g (areas where sea sand blows as most cases were reported in US)
The only reason why OS advocates stupid rich settings during break in is because it saves them from warranty claims. If you break it in with a stupid rich setting--it won't seize up or fall apart--but your ruining the compression and longevity of the engine. OS doesn't care about that. They just want to make sure you don't blow it up while doing the initial break in--and then send it back for warranty. How long the engine lasts or how much power it puts out for the end user is of absolutely no concern to OS.
I use a fuel which is a blend of 20 % pure Caster Oil and 80 % methnol since here in Pakistan Caster Oil is very cheap and hi-quality.When it comes to lubrication nothing does it like caster Oil , its onlt downside is vanish residue.
Good for you. Castor is a very good lubricant.
The Lubrication mechanics inside an engines are Hydrodynamic lubrication and boundary layer lubrication.The shear characteristics of Caster Oil are superb as evident from the Bingham diagram and this is the area where it beats synthetic oils. Since in America most of commercial fuels available are either synthtic or blend with caster they dont offer superior protection at low temperature this is point where break-in is done and peel off may occur.
Again, your confused or mis-informed. Rich running is NOT going to make your cylinder peel. Lean running is what makes cylinders peel.
So the major cause of peeling or engine seizure is not 4-stroke running of 2-stroke engine but it is function of the fuel used.
Well, which is it? Now your saying that 4-stroking is NOT the cause of peeling--rather fuel. I think the part about fuel is total BS. As long as you run any commercially available fuel with about 16--20% oil your going to be fine as long as you don't get stupid and lean it out too much
Just to give you an example of how fine my engines are still running by using this break-in method I am quoting My 61 SF ABC. I log my flights and I ve done 150 flights with this one and it is still running as good as new, turning a MA Race tip 12 x 6 @ 12700 , 80 Methnol / 20 Caster Fuel, Ambient Temperature 15 Celcius, Plug OS # 8 , Elevation 700 '
150 flights is nothing. Put another 500 flights on it and then get back to me about longevity. That engine would still be almost new if you hadn't slobbered a bunch of fuel through it while you broke it in. You probably took about 3yrs worth of life out of that engine by not following the advice of all these guys on RCU that have told people time and time again how to break in an ABC engine.
Had you listened to all the guys who KNOW how to break in an ABC engine, it would be putting out more power, and it'll last longer in the end.
My 61FX would turn just about any 12-6 prop at 12,500RPM with 5% fuel and 6000' elevation.
You still got some learnin' to do. Get back to us when you have about 750 flights on that motor and let us know what prop it's turning and how many RPM after all those flights. Nice try though.