ColoNat
Well-Known Member
I have an 85... was designed to run on 91 Octane Leaded fuel w/o ethanol... everything near me has eth and is obviously unleaded... do these early engines have hardened valve seats or do they require a lead substitute?
LEAD replacement needed in early model engines?
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You don't need to run a lead substitue. You don't need to run 91. Regular, cheap gas is fine. Ethanol is an issue for everyone but sadly, unavoidable for most. If you plan on not riding the bike for any length of time, treat the fuel with a stabilizer of your choice.
ColoNat
Well-Known Member
naughtyG
Well-Known Member
Ya, all vehicles sold in the US since 1973 are unleaded fuel-friendly. No worries there, 87 unleaded is all the Max wants, even if it's hard to find without ethanol these days.
RaWarrior
Well-Known Member
The reason the sticker says 91 octane is because I seem to remember that is RON octane(used pretty much everywhere except US/Canada), while gas pump octane is (RON+MON)/2, or the more user friendly "anti knock index". 91 RON works out to about 87. Running "premium" will have zero benefit, and dyno testing suggests power is actually lost when used in a motor not designed for it. The ideal condition is to use the lowest octane possible without detonation, meaning the fuel mix is at it's absolute most volatile(just before it would light itself), when the spark fires it. High octane fuel is actually less volatile so it can tolerate more compression without detonating, but a low compression engine won't get the high octane mix to it's most volatile, and a small amount of power is lost because of it. This also results in cooler running temps than the motor was designed for, so carbon can build up rather than be burnt off.
The Vmax service manual says that any fuel with up to 10% alcohol is acceptable, so I wouldn't worry too much about fuel lines or anything like that. While I wish fuel didn't contain ethanol, for everyday use the "up to 10%" blend doesn't present much of an issue. My bike runs just fine on it. I've tried running ethanol-free(the marina where I work sells it for boats), and maybe thought it ran a bit stronger, but tough to tell. E10 presents problems when it sits around, especially in damp environments. If you burn through a tank of gas every couple days, you'll be fine. If you have to leave the bike for a while, fill the tank to the brim to prevent condensation, and then phase separation. And one more thing....additives that claim to prevent or "repair" phase separation are 100% fake. Rejoining the two phases is impossible, and the only way to "prevent" phase separation is to add MORE alcohol to the fuel and "force" the water back into the gas. Several of the "ethanol treatments" out there are 50% or more isopropyl (aka rubbing) alcohol. Adding that to E10 fuel can turn it into E15 or E20 depending on mix. Check the MSDS for the additive you use, using any that contain alcohol is furthering the problem, not preventing it. Here's a handy list I found about it...
http://www.fuel-testers.com/is_gas_additive_safe_with_e10_list.html
The Vmax service manual says that any fuel with up to 10% alcohol is acceptable, so I wouldn't worry too much about fuel lines or anything like that. While I wish fuel didn't contain ethanol, for everyday use the "up to 10%" blend doesn't present much of an issue. My bike runs just fine on it. I've tried running ethanol-free(the marina where I work sells it for boats), and maybe thought it ran a bit stronger, but tough to tell. E10 presents problems when it sits around, especially in damp environments. If you burn through a tank of gas every couple days, you'll be fine. If you have to leave the bike for a while, fill the tank to the brim to prevent condensation, and then phase separation. And one more thing....additives that claim to prevent or "repair" phase separation are 100% fake. Rejoining the two phases is impossible, and the only way to "prevent" phase separation is to add MORE alcohol to the fuel and "force" the water back into the gas. Several of the "ethanol treatments" out there are 50% or more isopropyl (aka rubbing) alcohol. Adding that to E10 fuel can turn it into E15 or E20 depending on mix. Check the MSDS for the additive you use, using any that contain alcohol is furthering the problem, not preventing it. Here's a handy list I found about it...
http://www.fuel-testers.com/is_gas_additive_safe_with_e10_list.html
