Changing amount of nitro. Problems?

[Vantskruv]

Hello!
So...I couldn't resist the eager to get my old Vibe 50 to air after much struggle with my old engine. I recently bought an YS56 with a Hatori 566 (or SAB 55) muffler.
So while waiting for it to arrive I'm having this dilemma:

I've a couple of gallons of Rapicon 20% fuel, which I used for my "dead" TT53. I also have a couple of gallons of Rapicon 30% fuel, which I'm using for my two working YS91SR engines.

I'm planning to run my YS56SR with the 20% fuel, and because of how expensive the fuel is nowadays, I also plan to run this fuel with my YS91SR engines when my Rapicon 30% runs out. So is it is applicable to change from 30% to 20% for my YS91SR engines? Or should I continue to use 30%?

I've read somewhere that you should not change the amount of nitro after the engine has be runned in, but I can't verify it. And also, how much more power and reliability do you get when running 30%? Is it really worth it compared to 20%?

[seanh]

I've always been told to break-in your engine with what you plan on running. So on that point, if you've run 30% stick with it. But if you want to change nitro content, it's fine.

other than tuning, you might want to run a cooler plug to decrease timing. From what I understand, this will give a light increase in temp/power.

As to power differences? Doubt it's significant.

[Jafa]

You can chop and change fuel/nitro - don't worry about it

30% does give more power and it's handy for smack style collective thrusts and big collective pulls
If you don't fly that way then no need to pay more for 30%, just use 20%