Does fuel's Ron affect idling stability???

[zirconxi_imp]

Hi All, interesting thing I encounter today, I ran my CB till the tank almost empty and pump in 12Liter of fresh RON97 fuel. I believe the '13 CB tank is only 13L.. Previously the bike was running on RON95 fuel. Right after I refuel, my bike started to run a bit high on idle on a warm engine (about 1250rpm). Then I did a throttle position reset and now the idle is fluctuating between 1000 and 1100, jumping up and down quite actively. Before this while running on ron95, the idle was stable at 1050. After the bike cold down I wash the bike and after washing, the idle become stable at 1050 again.

Is the ECU learning to adjust to new fuel? or I ran the tank till too low and fuel pump is hurt? or the mysterious idle unstable issue?

Does our CB have any knock sensor that will adjust Ignition Timing based on knock sensor??

[Lord Popgun]

Don’t know what is going on, but the CB1100 does not have a knock sensor.

Running any vehicle down to almost empty is not a good idea for a few reasons.

[pdedse]

Hi All, interesting thing I encounter today, I ran my CB till the tank almost empty and pump in 12Liter of fresh RON97 fuel. I believe the '13 CB tank is only 13L.. Previously the bike was running on RON95 fuel. Right after I refuel, my bike started to run a bit high on idle on a warm engine (about 1250rpm). Then I did a throttle position reset and now the idle is fluctuating between 1000 and 1100, jumping up and down quite actively. Before this while running on ron95, the idle was stable at 1050. After the bike cold down I wash the bike and after washing, the idle become stable at 1050 again.

Is the ECU learning to adjust to new fuel? or I ran the tank till too low and fuel pump is hurt? or the mysterious idle unstable issue?

Does our CB have any knock sensor that will adjust Ignition Timing based on knock sensor??

I can't answer any of your questions, but several CB1100 owners, myself included, reported that the high idle started immediately after filling the tank after a substantial ride, meaning bike was fully warm if not quite hot. I don't recall if the gas was different that first day. The idle spike I experienced was more in the 1500-1700 range, and once started, it wouldn't come down from that. Next ride, all would appear to be ok for 5-10 minutes, then high idle would start again. Over time, mine morphed into low idle issue as well.

[dave]

Hello zirconxi. My idle instability began the same way you describe, and I though maybe it was the fuel also. I am sorry to inform you, but it sounds like your IACV is on the way out and the only way to fix the problem is to replace the IACV. Some days it will work fine, other days it won't.

[Speed_imp]

Hello zirconxi. My idle instability began the same way you describe, and I though maybe it was the fuel also. I am sorry to inform you, but it sounds like your IACV is on the way out and the only way to fix the problem is to replace the IACV. Some days it will work fine, other days it won't.

Luckily or unluckily I am the last CB 1100 owner to confirm your theory, tried with 95 or 98 Octane, tank full or empty, performed the throttle adjustment procedure... no way. Issue always came back after some kilometers at the beginning of the idle issue and lately it came back almost inmediately, most of all with traffic and stop and go circumstancies.

[Cormanus]

I think the ‘13’s tank is actually 14.6 litres, so there should have been a bit of fuel left.

[zirconxi_imp]

...hmm, so few owners idle problem began this way.....
Ok, will monitor again and if it is getting worst will update in the idle instability thread.....Thks all...

[Cormanus]

I hope it's a just a temporary problem for you zirconxi.