ORIGINAL: Dr1Driver
15% nitro is uneccesary.
In your opinion. Some people like it. Personally, it makes my engines start easier and idle better. Not theory, practical experience.
Which still doesn't make it a necessity. You'll have slightly more power with 15% and it might be that an engine starts more easy, however I have never had starting problems using 5% nitro. I start all my engines (4, 3 twostroke and 1 fourstroke) with a chicken stick and have had no problems starting it.
What i ment is: a two stroke engine will run fine on 5%. You won't damage it and it will run. 15% nitro might have some advantages, but it's not neccesary.
For engine break-in, castor oil might be slightly better, because it is in fact an inferior oil to the synthetic oil used in Coolpower.
Absolutely wrong. Prove it. In fact, castor will hold up better in some conditions than synthetic will. I don't think Morgan's puts "inferior" oil in their Omega. I've used it for years in sport and competition planes. My engines start easily, have good power (.32s turning 10x4 props at over 14k), and give me no trouble.
I don't know about Morgan's, it's not available over here. So can't say anything about that. Over here we get coolpower or 'own mixtures'. Worst oil is recinus. If you do your engine breakin on 20% recinus, 75% methanol and 5% nitro, you'll get better results than using coolpower, simply because the oil in coolpower lubricates better, which slows down the break-in process. I didn't believe that myself, until someone asked me to flip his fresh-broken-in OS 46FXi, which had tons more compression after breakin than my 46FXi (which was broken in with coolpower).
To prevent misunderstandings, I'm referring to two-stroke engines here. I also own a fourstroke and use 10% nitro with 'klotz' oil. For breakin I used 5% nitro.
Keep in mind that fuel might be more expensive here (The Netherlands). I pay like 22 euro for a gallon 5% coolpower which is about 28 dollar. 15% nitro costs somewhere around 32 euro here, or about 42 dollar. I guess you can imagine why i run 5% coolpower (fly about a gallon a week), however I must admit that I have tried 10 and 15% but noticed no difference, besides having slightly more power. If starting your engine is a problem, it might be that it helps, however my engines all start within 2 or 3 flips with a chicken stick.