No worries..think of it as the old choke on carbed engines. Does the same thing (or is designed) to allow a richer mixture during cold starts...
I am not a mechanic or a physicist, but I did stay at Holiday Inn Express in Albany once (very generous continental breakfast and nice rooms).
For whatever it is worth, I read that the ethanol in gas actually serves a cleanser; after all, it is alcohol; and that fuel injector cleaner has become obsolete. I am not saying you or anyone else is wrong, just parroting what I read. In my own experience, ethanol gas is a big no-no in carbureted two-strokes because the cleansing action can free up grime that would otherwise just stay in the bowl or other parts of the carb but get washed away and end up in bad places. This, in turn, can partially plug a jet, creating a lean condition ... and a lean condition on a two-stroke = pistons melting.
Former Ride:
2013 F6B Standard, black; sold 7/2019
Latest Addition:
2016 Gold Wing Level 3, red; SCT transmission stuck in manual mode
2019 Miles:
7,900 as of 10/6
There would be no code since the ECU thinks its doing what its supposed to.
I read a lot about this before I got mine. It is programed that way, And Honda will do nothing under warrantee.
There are even units designed to fool it into thinking its seeing a different air temp than what it actually is.
But I guess they don't always work.
Its the air temp to fuel ratio thats causing the stumble.
The ECU is cutting the fuel mixture down before its warmed up enough.
They have this all figured out when you get the reflash done.
Getting my reflash done this fall.
ITS ALL GOOD
It looks like every member who has contributed to this thread is from the eastern half of the country. Is this a data point that is of any value? Fortunately, my 2016 has been flawless for 23,000 miles. I should probably go for a ride today just to make sure.
allen
My bike is still under warranty and a re-flash might void it. The Boosterplug can simply be removed. It's $150 bucks well spent.
Exactly..the bike is set to a lean condition, hence the stumble when cold. To much air and not enough fuel...The enriching circuit is not good on these machines. Could be bad mapping of the ECM, mismatched factory sensors (with ECM). Several components come into play on this circuit (cold start).
Please investigate ethanol fuel before making assumptions. With water and vapor issues it is not recommended over ethanol free fuel.
I believe I've had the stumble once or twice, however I usually let the bike warm up for a minute or so as I close the garage and put on my gloves. Given my experiences with different vehicles and MC's I would tend to agree it's something with the ECM. I know my VTX gets crap for mileage if it's under 80 degrees out. It could be that wherever the B reads the temperature at gives a false value. My buddies truck (yes yes different animal) has an issue on the cold weather circuit on his ECM that causes similar issues to the stumble described by many here.
Sensors and gizmos oh my, sometimes I'd prefer that carbureted mule. Easier to diagnose and repair.
Gents, on my 2013B I experienced that stumble only on one occasion or should I say for one tank of gas. I have always run premium fuel and after reading other threads I decided to try Mid-Grade gas and the stumble appeared and stayed till I filled up again. If you haven't tried Premium fuel exclusively you might just find the solution there. I do not get any stumble warm or cold, low RPMs or high. Just Sayin.