Hesitation? Not running smoothly?

[rboe]

When I have bad gas people prefer I ride the bike vs. stinking up the car.

[CB1100EX2_imp]

Wow this really worked!

I too been experiencing issues with my 2017 CB1100EX. It has just shy of 10,000 miles on it to date. The engine braking was horrible i.e. always lunging me back and forth and getting progressively harder to smoothly roll off the throttle. Sometimes the acceleration would be erratic. Today I rode to lunch and it was the worse. It felt just like bad gasoline which I have had happen twice now from using out of stored cans. (Side note: Red StaBil seems to stop working in less than a year.) Well the acceleration was terrible today on my way to lunch. I mean it was seriously dangerous, so much so that I was about to make an appointment with the dealer. I read this thread at lunch and thought "No way but I sure hope this works." Well it did. My bike was super smooth on the way back and even the engine braking was normal and not throwing me up on the tank.
I am glad this post exists and will hopefully add something useful too. For now I just wanted to add another check mark to the "it worked" category.

Jeff

[Cormanus]

Welcome to the forum, CB1100EX2.

[GoldOxide_imp]

Hey, welcome to the Forum CB1100EX2. Well, when not elsewhere, you will [always] be here.

[Brandontrain_imp]

I bought a used 2014 CB1100 with 1000 miles on it a month ago (December 2021). The bike is in immaculate condition. Has slight hesitation on acceleration from 1000 to 2000 RPM. At idle the RPM is surging at time from 900 to 1100 RPM. On the freeway it ran perfect. I hooked up a scanner to check for any stored trouble codes, there is none. Live data showed everything normal. I took a wild guess and replaced the IACV, reset the TPS. It started up and ran fine, took it for a 2 miles ride, all good. Next morning, hesitation condition came back, this time worse than before. I removed the spark plugs, #1 plug is black (misfire indication). Did a compression check, all cylinders are reading 175 PSI (WOT).
Put the sparkplugs back in and do a power balance test. #1 cylinder only has 30% drop. Did ohm test on the spark plugs and ignition wires. All read the same. I went ahead and replaced ignition coil #1,4 and all spark plugs. The bike ran perfect now. It is strange that the coil went bad at 1000 miles, and it acted like the IACV not working properly.

[GoldOxide_imp]

I've read on another Forum of a similar uncommon example of your experience Brandon. Ultimately they ended up replacing the Honda coil too. It could be possible the manufacture of the coil had a marginal short that manifested with use (i.e. with heat and/or vibration).

Glad you overcame the impairment. It must feel satisfying. Congratulations!

... and welcome to the Forum!

[the Ferret]

I wonder if Brandon's IACV is still good and would come in handy for someone with the high/low idle issue. Any way for him to check to see if it's still good (provided he didn't throw it away already)

[peterbaron]

IMHO the amount of work/labour in replacing IACV does not justify using an old part, $110.

[max]

Good job Brandon, interesting about the no 1 plug being black.
The waist spark system is normally balanced as you know very well and i think you connected the no 1 plug so it would still fire no4.

The rpm dropping from 1050 to 900 would indicate one cylinder dropping out with fuel still injecting in no 1, could have been checked with a secondary ignition pulse on the no 1 spark plug lead with a scope on both no 1 and 4 to compare maybe? ( and you could see that one spark is positive and the other negative with regard to chassis, surprise! )

If the no 1 cap was faulty that would still affect the no 4 i think, ( reduced high voltage ) but like GO said if the coil had an internal path to ground on the no 1 side then you have the effect only showing up on no 1 cylinder.

Since the voltages are so high it seems hard to test this other than setting the coil up with two known good plugs connected AND earthed to the coil metal core plus one side of the primary winding for the same reason and slowly reducing the 12 volt supply until one plug quits?

Anyway good on you for getting to the bottom of this and thanks very much for sharing this experience, great style repair job

[Lord Popgun]

Sorry Max, I just can’t resist. Forgive me

In the US we did not get the waist spark ignition. Nope, we got the waste spark ignition.

Max, I have a wireless tach that also have a high voltage function. You hold the end of the antenna on the plug wire and it displays the KV. I should check mine sometime for a baseline.