Originally posted by Johnnytc3
I plan on breaking in some engines but all i have is maxy 40 percent fuel, people say lower nitro content for break in, but does it really matter ?
That is because most mfg would like to suggest you to use high % lubricant when run-in.
20% Nitro may have 20% Nitro / 15%castor and synthetic oil / 65% methyl alcohol.
40% Nitro may have 40% Nitro / 9%castor and synthetic oil / 51% methyl alcohol.
More lubricant is good for break-in and your sleeve will not get scratches. If you want to use your 40% still ok if you add 2% castor oil.