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IDLES LIKE CRAP IN ROCK

  • <i class="fa--xf fal fa-check "><svg xmlns="http://www.w3.org/2000/svg" role="img" aria-hidden="true" ><use href="/data/local/icons/light.svg?v=1758297946#check"></use></svg></i> Discussion starter Discussion starter David R
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BT Moto suspecting 'fire order change' probably means that in Rock Mode, the R18 ECU might be firing on each cylinder upstroke, not only every second upstroke, like the older loping Harleys did—or randomly in that vein.
 
estoma said:
BT Moto suspecting 'fire order change' probably means that in Rock Mode, the R18 ECU might be firing on each cylinder upstroke, not only every second upstroke, like the older loping Harleys did—or randomly in that vein.
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Uhhhhmmm now I am completely confused ... a 4 stroke engine fires @ TDC of the 'compression stroke' .. that is the only way it works ... older Harleys had something called a 'wasted Spark' that means they fire on every rotation (mechanical ignition 2 lobes on the ignition cam) ... which doesn't do anything because it is right after the 'Exhaust' stroke when the cylinder is empty ... the 'loping' simply happens because Harley is a 45º V-engine and it fires not one-and-then-the-other it fires pop-pop-noting-pop-pop and so forth ... you get the idea ;)
... just my 2¢ :)
 
valkraider said:
Yeah, they can make massive changes, 100% change!

Original: 1-2-1-2-1-2-1-2-1-2
New: 2-1-2-1-2-1-2-1-2-1

Its like night and day.
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This reminds me of an old "Futurama" episode where Bender had a nightmare.

He dreams in binary, and he swore he saw a "two"!!!!

Maybe OP's R18 saw the same thing in "ROCK" mode 🤣

Futurama I saw a 2.png

Mike
 
It says in the owners manual that its rocky at idle in rock mode under Engineering technical info, page 117 in Canada
 
David R said:
Something tells me that I will not be able to get this to idle smooth in ROCK.

It sounds terrible. Anyone tried to smooth it out?

I usually leave it in ROLL so when I stop, it does not shake and sputter while sitting at a light or when ever. Its smooth as can be. It should do that in ROCK too.

I am a life long mechanic. I remember folks telling me "its got a performance cam in it so this is the best it will Idle". Or "Its a performance engine" "Its supposed to sound like that".

Suggestions? Ideas?
David
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I run nothing but 90 octane pure gas in all my bikes and equipment; it's a little more expensive but well worth it. My GSA starts on the first crank even when it's in the 30's. I put 93 octane ethanol in my Honda generators and I had to pull till my arm hurt. Drained the fuel, put pure gas 90 octane in, they start after three pulls max. Ethanol is crap, it kills your gas mileage and eats up plastic. Ducati had to replace fuel tanks on a lot of their bikes because the ethanol was making them separate and swell.
 
Ethanol is a debate that is old as time, like oil, tires, and pineapple on pizza.

There is lots of anecdotal info, and lots of complex info.

The reality is that in the USA at least nearly everywhere has had E10 in pumps since the 90s. Vehicles are made to work with that, and have been for decades.

The only real considerations are for storage, or use near water (boats).

The only thing that I can guarantee - just use good gas from reputable suppliers. Most important is that their gas is turned over - gas ages in the tank at the station too. Old gas is not cool.

Now - octane. That is a different thing entirely. Generally - octane need is a function of compression ratio and timing. Using higher octane than is needed won't buy you anything - and actually will ever so slightly reduce your fuel economy (as more octane means less fuel - but it will probably be so small as to not matter). But basically - if an engine doesn't require 93 - don't use 93. Use the lowest octane your manufacturer recommends. Octane doesn't make the fuel any better, it only reduces detonation issues.
 
valkraider said:
Ethanol is a debate that is old as time, like oil, tires, and pineapple on pizza.

There is lots of anecdotal info, and lots of complex info.

The reality is that in the USA at least nearly everywhere has had E10 in pumps since the 90s. Vehicles are made to work with that, and have been for decades.

The only real considerations are for storage, or use near water (boats).

The only thing that I can guarantee - just use good gas from reputable suppliers. Most important is that their gas is turned over - gas ages in the tank at the station too. Old gas is not cool.

Now - octane. That is a different thing entirely. Generally - octane need is a function of compression ratio and timing. Using higher octane than is needed won't buy you anything - and actually will ever so slightly reduce your fuel economy (as more octane means less fuel - but it will probably be so small as to not matter). But basically - if an engine doesn't require 93 - don't use 93. Use the lowest octane your manufacturer recommends. Octane doesn't make the fuel any better, it only reduces detonation issues.
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What he said. Wise words about something often mis understood.

On the other side, Knock sensors have allowed people to use lower octane. They claim the car runs fine. Well it does, but one has to define fine. It works, likely due to reduced timing and changing of other parameter which all result in performance loss.
 
One fun thing about octane - is altitude. :) In the Rocky Mountain states it is hard to find high octane fuel, all their octane numbers are lower in general. Lower atmospheric pressure at high altitudes means you need less octane to prevent knock. Just burn it up before you drop back down to the lowlands and its all OK.
 
valkraider said:
One fun thing about octane - is altitude. :) In the Rocky Mountain states it is hard to find high octane fuel, all their octane numbers are lower in general. Lower atmospheric pressure at high altitudes means you need less octane to prevent knock. Just burn it up before you drop back down to the lowlands and its all OK.
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I like to limit, or at least take care of, the petty things in my life so I have brain space and time for the important things. For the price of a couple cups of Starbucks I can spend the year sloshing in the best stuff I can find where ever I stop and never even give it a glancing thought.

YMMV.
 
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