BMEP Brake Mean Engine pressure or PSI exceeding right around 120lbs engine warm, or more is when you need to consider using fuels other than pump gas, say 140-150lbs or more.. . Cylinder Pressure of 90lbs or higher is good up to 115-120lbs or so. Keep in mind these are engine warm measurments. I have found that a 120 warm can be 150 cold. When you get to these higher pressures, under detonation you can put more than 400lbs of pressure on the wrist pin and crank pin, crank ect.. This is a lot ! These little F50 and F80 engines are really not made for such pressures. You can bend wrist pins and cause bearings to fail under such pressure. You can increase power by adding compression.. But as with many things, there are limits.. If you keep engine BMEP around 100lbs or so, and open your exchange ports, port match the intake and Exhaust to exhaust pipe, you will gain amazing power. All with out adding compression.. Another aid to power is oil. More oil adds power. More 2 stroke oil in your fuel will add power. The extra oil helps to seal imperfections in cylinder wall, helps cool better, which all adds up to more compression and more power.. Here again.. There are limits.. Once you exceed 18:1 or there abouts,. Say.. You go to 15:1 or 12:1, you start to get too much oil and not enough fuel to burn, and you begin to lose power.. But on the positive side, you will not hurt your motor because of too much oil. Never had that happen where I hurt a 2 stroke engine because of too much oil in the gas.. Currently on my KTM and KX 2 stroke race bikes, the factory states that mix on these race bikes is 32:1.. And these are expensive race bilks to be sure.. And so..With that, I also tell my customers to never run less oil than 32:1 mix. Also.. I have spoken to racers in Canada that use the Opti lube and they never go leaner than 60:1 using that stuff and they educated me on the process of getting to that mix ratio of 60:1. Yes.. It is a process.. Anyway.. Enjoy the ride..