As we all know the the debate about high octane and 2 stroke barely ends. So my question will basically go around this topic but not go indepth. So, recently I purchased a 1980 Yamaha DT175F (MX) and due to the fact that I'm lately busy, I just kick start it on weekends for a few mins then turn it off. So I was thinking of getting 3 or 4 gallons 100 octane and since my local shell gas station has got an offer on 100 octane for a while now so I wouldn't pay a alot more for the normal 95 octane. The reason for me wanting to get some litres of 100 octane is that it stays fresh for a longer time inside the tank rather than both affecting the fuel it self and the tank when normal fuel is used. What worries me is that I read on some site that 100 octane fuel can literally melt components of my engine. I would like your opinion fellas!

Thanks in advance

Be more worried about the ethanol in the fuel. It eats old rubber.

I just use standard 95 unleaded in my bikes. Can't be ar5ed to search the country in the hope that I can find some super fuel.

Boom.

Your engine is designed to run with lower octane fuel for your market, im assuming US with an'f'.

Unless you retune adjusting the timing for the 100 you will kill the piston. Aircooled Dts are sensitive to hot spots on the piston the piston temp on 100 grade fuel may be a step too far too.

Be more worried about the ethanol in the fuel. It eats old rubber.

I just use standard 95 unleaded in my bikes. Can't be ar5ed to search the country in the hope that I can find some super fuel.

I guess I shall just stay with the normal 95, not that its any bad in the first place, just thought the 100 would be better but gladly mistaken. Thank though.

Boom.

Your engine is designed to run with lower octane fuel for your market, im assuming US with an'f'.

Unless you retune adjusting the timing for the 100 you will kill the piston. Aircooled Dts are sensitive to hot spots on the piston the piston temp on 100 grade fuel may be a step too far too.

I'm assuming its for the American market since the frame code isn't 2A7 (MX). Mine has code 3G6