I suppose 87 octane is minimum but we always use premium. Some say 87 builds more hp, that is not a huge requirment for me. I want longetivity and reliability. Al
alswagg said:
The reason I asked is that you're more likely to get fresh fuel from a pump labeled 87 than one labeled 91. But even stale 91 is going to be higher than 87... hopefully.
Since your sleds don't require a minimum of 91 the premium you're using (even if it isn't actually 91) I'd guess is more than enough to combat detonation... even in the Viper.
I do agree with what you are saying especially mid grade, 89. Who uses this? 91 or premium get used more in summer time due to high end cars. Up North 91 is used alot in sleds I believe. Maybe just lucky. In my younger days I remember running right on the edge, utilizing pyrometer gauges, piped, carrying jets, rejetting as the day went on. Lol So many burn downs. Now, I prefer to keep it running, may not be the fastest but nobody pulls me down the trail either. Al
alswagg said:
gbic1
New member
The pumps by were we stay in Wisconsin have no Ethanol in their premium. So I use their premium. I am all stock 98 700 red head. Sled has 5600 all Wisconsin miles .
Nobody has yet hit on the reason alcohol in the pumps burns down sleds.
IT TAKES TWICE THE AMOUNT OF ALCOHOL AS GAS TO RUN AN ENGINE
Soo, if you try to run full alcohol in your engine (I did for years in a super modiifed) You need to be able to deliver twice the fuel.
So if you add 10% alcohol you LEAN the existing system. If you are already on the edge of lean....well...you know. NOW, if the pump happens to have even more than 10% look out!!
One more thought. When I ran it in my super mod we would unhook the fuel line and run gas through it before storing it as alcohol will disolve aluminum...or at least corrode it with that white stuff as described in a previous post.
IT TAKES TWICE THE AMOUNT OF ALCOHOL AS GAS TO RUN AN ENGINE
Soo, if you try to run full alcohol in your engine (I did for years in a super modiifed) You need to be able to deliver twice the fuel.
So if you add 10% alcohol you LEAN the existing system. If you are already on the edge of lean....well...you know. NOW, if the pump happens to have even more than 10% look out!!
One more thought. When I ran it in my super mod we would unhook the fuel line and run gas through it before storing it as alcohol will disolve aluminum...or at least corrode it with that white stuff as described in a previous post.
WRONGstingray719 said:
You ran gasoline through it because alcohol washes the oil off of the metal. It also would dissolve any rubber in your fuel system. It also attracts moisture which will cause your fuel system, and engine internals to rust, as it washed all the oil off of your cylinder walls etc... That was 100% alcohol, or methanol in a super mod.
As for a two stroke engine, oil, mixed with the fuel is needed to lubricate the entire rotating assembly, not just the piston, and cylinder walls. There are many small bearings in your motors which depend on that oil in the fuel to live. Remove that oil, and the motor is not going to last too long. Enter alcohol no matter what form it is in to that fuel, and it makes your oiling system less efficient. Alcohol is an excellent cleaner of oil. The alcohol will actually lift oil off of any surface, and will surround the oil molocules to prevent it from sticking. That is what it does to your engine internals. Too much alcohol, and I think you know what happens. A 2 stroke engine can safely handle up to 10%, adding anymore is dangerous. The idea of enrichening your your mixture to combat the alcohol is not a good idea' Running rich keeps your internals wet with gasoline, and alcohol and will contribute to a crappy running, short lived motor. Keep it tuned, and the carbs clean, and you'll be fine. I personally run mid grade fuel. Not because I need it, but around here regular contains up to 10%. Mid up to 5%, and premium 0% at some stations. I like to stay away from ethanol, but don't need, or want to pay for premium
LOL, there is always one huh?
In a super mod we could care less about washing oil off metal as it is a four stroke. Super mods have a special fuel system so rubber is not an issue. Alcohol bladder (looks like rubber but is not) will disolve if you put gas in it. Supers also have filtration designed to keep water out.
NOW, put full alcohol in low grade aluminum as most fuels systems are made of and go back and check it a month later and see how much aluminum has corroded and disolved. When I ran an alky carb I forgot to drain the bowls on a Holley and somewhere I still have that mess.
Anyways I can tell you that alky is a truly horrible thing to put in a two stroke, I think we all agree on that.