lol - you dont have to change your piston and sleeve if you change fuels or percentages of nitro content.
It is suggested that you maintain the fuel you break you engine in with for the duration of the engine. That is purely because your engine is 'used to' it and you have properly tuned for it.
Switching fuels may bring cause to adjust your needle settings.
Switching nitro content can do the same.
Keep in mind, running 10%, 20% and 30 can all have varrying effects on temperature conditions. If you do not pay mind to that impact, it COULD have adverse results. But the same can be said if you dont pay attention even with what you are running now.
Changing the piston and sleeve because you change percentage of nitro is not reality.
The ONLY time I suggest changing ANYTHING internally, are the shims, and that is only if you go from 10% to 30% and cold plugs to hot. You are in fact chaing the timing by changing the plugs, and therefore, may have to increase the amount of head shims you use to allow for more fuel to build up before firing.
But that is a WHOLE DIFFERENT SUBJECT!
Good luck man....
Go Odonnle :thumbup: