OK so I got me Global Freestyle all ready to go and I got my YS53 four storke mounted and I got my 15% oil 10% nitro fuel ready to go. How much caster do I add to give me a 20% oil mix?

try this link


http://www.nitrorc.com/


see the custom fuel section, great mixing chart!

You don't add ANY castor oil.....because it's a YS.
They recommend only synthetic oil for their engines.
Castor gums up the regulator and piston ring.
If you must add oil, add about 4-5 oz of Klotz synthetic oil.

For a gallon, I calculate 8 ounces.

I did this quickly, so I may be mistaken, but:
.15(128)+x=.2(128+x) Solving, I get 8 ounces.

In 128 ounces, 1 gallon, of fuel with 15% oil, there is .15(128) = 19.2 ounces of oil
Adding 8 to this gives 27.2 ounces, but we now have 128+8=136 ounces total fuel.
27.2/136 = .2 or 20% oil.

You'll need to do this in a larger container than a gallon fuel jug.

The formula, as I make it, would be:

Oil Added = (fuel amt) times (new% - old%) divided by (1 - new%)

Check out the link above, it is a mixing calculator

I would not use caster. I would use a good synthetic

You can download my fuel-mixing spreadsheet from http://www.redb.5u.com/
Its a 20kB MS Excel spreadsheet. Enjoy!

/Red B.

My vote also goes to the not add castor column.

You risk gumming everything up and then those horrible stais on the muffler.

Taxman

Adding oil will reduce your nitro content even further (below 10%). YSs prefer 20% or higher. Do the decent thing and buy some 20/20 fuel, and don't bother fiddling about mixing your own.