Octane Boost
Road Master
Joined: Nov 2022
Posts: 802
Likes: 394
From: Missouri
Mixing Fuels and Calculating Octane (sunocoracefuels.com)
octane booster generally did squat,,,,say 91 and add a bottle, you may get 91.8 with a really good booster.
octane booster generally did squat,,,,say 91 and add a bottle, you may get 91.8 with a really good booster.
Road Warrior
Joined: Nov 2022
Posts: 1,539
Likes: 543
From: MN
Stock M8, here. No need for octane boost - the ignition timing and compression ratio doesn't demand it to prevent knock.
Those that mod the motor to boost power need to look at build formula for extra octane needed. Otherwise increasing octane can actually be harmful because the gas formulation has extra resistance to combustion that the engine can't burn, so you increase cylinder and valve deposits. Running the correct octane is important.
I also run non-oxy (no ethanol) gas. Even the M8 can tolerate 10% ethanol, it increases fuel consumption quite a bit. This means more frequent refueling, which is significant for only a 5 gallon gas tank. Non ethanol gas is also more stable and doesn't degrade as fast. So I don't add a fuel stabilizer in summer when I ride a lot.
In winter I always store the bike with Stabil fuel stabilizer - as with all my seasonal engines. They never fail to start in spring. I never run them dry, either. Older seals and gaskets dry out and crack causing leaks and air ingestion.
Those that mod the motor to boost power need to look at build formula for extra octane needed. Otherwise increasing octane can actually be harmful because the gas formulation has extra resistance to combustion that the engine can't burn, so you increase cylinder and valve deposits. Running the correct octane is important.
I also run non-oxy (no ethanol) gas. Even the M8 can tolerate 10% ethanol, it increases fuel consumption quite a bit. This means more frequent refueling, which is significant for only a 5 gallon gas tank. Non ethanol gas is also more stable and doesn't degrade as fast. So I don't add a fuel stabilizer in summer when I ride a lot.
In winter I always store the bike with Stabil fuel stabilizer - as with all my seasonal engines. They never fail to start in spring. I never run them dry, either. Older seals and gaskets dry out and crack causing leaks and air ingestion.
Seasoned HDF Member
Joined: Jul 2017
Posts: 5,749
Likes: 1,603
From: High Point, NC.
At least here in NC with our gase, thats what I experienced.
HDF Community Team
Joined: Mar 2008
Posts: 1,892
Likes: 552
From: NH
Not sure thats correct. I thought the same thing last year when I started running the cheaper octane gas on my SE stage 2 bike. Pinged like crazy! That was also the same time I took my bike to have it dynod. MY guy called me and asked if I was running lower octane. He said he'd been trying to get the bike dialed in all day and it was still pinging. He wound up flushing the tank, putting the higher octane gas in and finished the dyno.
At least here in NC with our gas, that's what I experienced.
At least here in NC with our gas, that's what I experienced.
Last edited by bradsULtd; Jun 29, 2023 at 04:30 PM.
Advanced
Joined: Jul 2022
Posts: 55
Likes: 4
From: Riverview Fl
I just took a road trip (on my car) up to Chicago and in Georgia I found , non ethanol gas but at 87 octanes, perfect for my other bike..but here in Central Fl., I get Non-ethanol 90 octane, and I don't hear any pinging (my old 78 triple did pinged and I would hear it ), and that is even after a cam upgrade, but I do have a hiccup in 1st gear I don't like and talked to a Dyno shop and they want "premium gas" didn't specify the octanage...so I was wondering if for dyno purposes I need to use gas 91-93 and 90 won't do it!
Stellar HDF Member
Joined: Jan 2017
Posts: 2,673
Likes: 2,079
From: Massachusetts
I just took a road trip (on my car) up to Chicago and in Georgia I found , non ethanol gas but at 87 octanes, perfect for my other bike..but here in Central Fl., I get Non-ethanol 90 octane, and I don't hear any pinging (my old 78 triple did pinged and I would hear it ), and that is even after a cam upgrade, but I do have a hiccup in 1st gear I don't like and talked to a Dyno shop and they want "premium gas" didn't specify the octanage...so I was wondering if for dyno purposes I need to use gas 91-93 and 90 won't do it!
Advanced
Joined: Jul 2022
Posts: 55
Likes: 4
From: Riverview Fl
Well non-ethanol I think is a lot better when you don't use the vehicle that often, then it is just one octane short of the 91 and since it is so humid here in Fl., (I already had a tank full of rust in my other bike using ethanol gas) it is a preventive measure and both of my bikes aren't pinging (my other bike actually calls for running on 87 Octane). That's why I use it, I was just wondering if an octane booster would help my ethanol free get to the 91 HD recommends. In my old 78 bike the 107 octane booster eliminated the pinging, and it was bad, it was a triple.
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Seasoned HDF Member
Joined: Jan 2008
Posts: 13,654
Likes: 11,424
From: State of Confusion
I keep some of this on hand, I trust it ... and took a bottle with me on my 4000 mile midwest road trip last year and used at times when there was some stations with somewhat questionable fuel quality, basically non top tier
https://www.goldeagle.com/product/st...60-protection/
https://www.goldeagle.com/product/st...60-protection/
