Intermittent loss of power during acceleration

[suprsnake]

I have a 2017 Road Glide M8. This problem started at 17k miles, the  bike currently has 21k on it  Intermittently while accelerating in any gear, but most frequently 4,5,6 it will stumble and have a muffeled back fire and if you maintain that throttle position it will maintain the stumble. I had it into the dealer for this problem. They could duplicate the problem, then changed the spark plugs and the problem went away, only to return after 1200 mi.  This mostly occurred between 1700 and 2500 rpm. It has happened on flat ground and on hills. On the last 4 rides, it has exhibited this problem on the first leg of the ride (60 to 100 miles) and after a stop of an hour or more it will run normal on the second leg of like distance. These rides have been in temps of mid 40s to mid 70s.
I have called the dealership and have called Harley proper. Their fix is ride it till it breaks ... They are not willing to troubleshoot it. Has anyone else experienced this

[1FSTRK]

Is it totally stock?
If not what changes?

[suprsnake]

My Road Glide is totally stock... Tune is up to date.

[HV]

I had one doing this....when the engine was installed at the factory the Crank Position Sensor in the bottom of the Engine had its wire jammed under the front engine mount and shorting randomly....worth checking for this...  

[Scotty]

I had one doing this....when the engine was installed at the factory the Crank Position Sensor in the bottom of the Engine had its wire jammed under the front engine mount and shorting randomly....worth checking for this...

Wow how long did that take to find?
That one would have had me scratching my head for weeks.

[suprsnake]

Thanks for the Response
I neglected to include the information that this bike had blown a head gasket. This would cause the tank to be removed during repair. I had no problem with power loss before this and it did not show up till 5000 mi. after. The possibility of a pinched wire taking time to intermittently cause an issue, then when changing spark plugs the tank would once again be removed possibly allowing a wire to not short for a period of time then to start again...I'll check on this scenario I
     

[HV]

I had one doing this....when the engine was installed at the factory the Crank Position Sensor in the bottom of the Engine had its wire jammed under the front engine mount and shorting randomly....worth checking for this...

Wow how long did that take to find?
That one would have had me scratching my head for weeks.

Found it when the Engine sumped and I had to install a new Short Block ....

[Hillside Motorcycle]

Working with a combination late Friday afternoon on the dyno, and witnessed a power loss, but thought it was a tuning move we made.
Kept tuning, then it became very clear that the case was filling.
Over 1 qt of oil was in the crankcase.
GIANT power loss then.
Opening it up this morning, to diagnose.

[VDeuce]

Scott, can you tell us what oil pump was in that engine when it apparently sumped?

[Heatwave3]

Working with a combination late Friday afternoon on the dyno, and witnessed a power loss, but thought it was a tuning move we made.
Kept tuning, then it became very clear that the case was filling.
Over 1 qt of oil was in the crankcase.
GIANT power loss then.
Opening it up this morning, to diagnose.

Scott, any update on what oil pump was installed?

[BVHOG]

Make sure the plug wires under the tank are fully engaged on the plugs, they can be a bear at times.