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I run 93 octane in mine almost exclusively. New, there was a sticker on the tank that said 90 octane minimum. Mine has different intake, exhaust and tune. So 93 octane is just good business. Only time I ever ran 87 in it was when out riding, needed gas, and the only nearby station only had 87. I put maybe half a tank in it and babied it until I found some 93 at another station.

Sometimes I mix half a gallon of 110 octane Sunoco in it. but mainly just for the lovely exhaust smell .
 

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Higher octane produces less horsepower unless you increase compression. Higher octane allows you to run higher compression. I only use 93 , even in the lawnmower because the 93 has no ethanol in it here. The pumps all say ''May contain up to 10%'' , but my own testing shows none. I haven't tested the lower grades. One of my bike I raised the compression from 8.3:1 to 10.25:1 , so I run 93 in that. You should test your local gas yourself. Octane boosters are basically diluting your fuel , less heat content. You can also raise the octane number for a high compression motor by adding 2-stroke oil , on high performance fuel injected cars it keeps the knock sensors from backing off the timing.
 

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You ever looked up the compression ratio for the M109R? It's pretty up there for a stock bike. Same for my B-King. And yeah, 93 here has no ethanol. There's 91 here without it, but I've used the same brand 93 practically since the day I bought the Nine, I'm just not going to change it. And also, it's an old school station. No card readers on the pumps. Pump first, pay later. Mikey likes it!
 

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I normally run 87 octane. When it is hot and when I know I am going to be running the bike hard will might use 90 or higher octane. I have only had problems (knocking) a couple of times running low octane when I don't downshift and accelerate too hard. I have been running mostly 87 octane in my ST-1300 for 24,000 miles and it calls for 90 octane.
 

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You ever looked up the compression ratio for the M109R? It's pretty up there for a stock bike. Same for my B-King. And yeah, 93 here has no ethanol. There's 91 here without it, but I've used the same brand 93 practically since the day I bought the Nine, I'm just not going to change it. And also, it's an old school station. No card readers on the pumps. Pump first, pay later. Mikey likes it!
All fuel is the same until it goes into the haulers , then the top tier brands add their additives. Off brand/no name gas is the same. NONE of the 93 here at any station actually has ethanol in it , yet a few of them still have the over priced advertised non-ethanol pumps.
 

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All fuel is the same until it goes into the haulers , then the top tier brands add their additives. Off brand/no name gas is the same. NONE of the 93 here at any station actually has ethanol in it , yet a few of them still have the over priced advertised non-ethanol pumps.
Well, I buy the 93 from a Sinclair station. But, the owner gets it from Arkansas. Has it brought in special, since 93 is kind of rare here in Oklahoma. And so, the 93 is actually Shell V-Power Nitro 93 octane.
 

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Well, I buy the 93 from a Sinclair station. But, the owner gets it from Arkansas. Has it brought in special, since 93 is kind of rare here in Oklahoma. And so, the 93 is actually Shell V-Power Nitro 93 octane.
I'm not a chemist so I'm not clear on the benefit of a non flammable , inert gas like nitrogen to an engine. A couple of my bikes don't like Shell V-Power.
 

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We have 87, 89 and 93 octane here, so 93 is all I use. Most of the time I fill mine up when my wife's C50T needs filled, so we fill hers first to get that little bit of 87 out of the lines.
 

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My friend organizes powerboat races and gets me 150 octane fuel regularly and I've been running that exclusively for the whole summer and I can tell you the difference on a stock bike is insane. And with octane boosters it's hard to keep the rear wheel from losing traction in 4th!
 

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Ok thx all.
I will use the premium to avoid deposits from ethanol..and not expect the perf gains of yesterday.
Years ago when I had a 1986 Honda Gold Wing, I was advised by a Honda mechanic not to use high octane fuel since the bike required only 87 octane. He said that he'd seen the combustion chambers of several Gold Wings that had been running high octane fuel and they had more deposts than those that ran only 87 octane.
 

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Higher octane pump gas has a slower burn rate than lower octane pump gas.
You want to run the fuel/octane that the bike was tuned for.
If your bike was tuned using 93 octane fuel you would not want to run a lower octane fuel as this will cause your AFR to move farther to the lean side.
And the reverse of that is using a higher octane fuel will move your AFR a bit more to the rich side.

The M109R states 90 octane from manufacturer, but running 93 - 94 octane is not a bad thing with the M109R.
The bike is tuned lean from factory so the higher octane will help prevent knock, richen your AFR a bit and the extra raw fuel left at the end of the power stroke helps keep down your cylinder temps.

BCS
 
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