HarleyTechTalk

Technical Forums => General => Topic started by: robertg on February 07, 2024, 10:42:02 AM

Title: 2021 M8 Touring Throttle Butterfly Barely Opening
Post by: robertg on February 07, 2024, 10:42:02 AM
I have a 2021 Touring that feels really sluggish, not much power. With the air cleaner off I can see that the butterfly will barely open when I try to rev it. Maybe 1/4". Is it supposed to do that with no load? I can't drive it on the road for a few more months.

The bike was in an accident last year before I bought it. No damage to the wiring or throttle that I could see. It had several codes after the accident which is normal. I cleared them and they never came back. When the bike was first started after the crash it was really sluggish, then it seemed to get a little bit better.

I was thinking it was sumping, but there wasn't that much oil coming out of the crankcase when I checked it.

I was going to try a new throttle grip sensor first. Does anyone else have any ideas?

Title: Re: 2021 M8 Touring Throttle Butterfly Barely Opening
Post by: Jamie Long on February 07, 2024, 02:33:40 PM
On 21-later models when in neutral and reving the engine the ECM only allows the throttle to open to 20% TP. When in gear & moving (or stationary and in gear with the clutch pulled in) it will operate as normal.   
Title: Re: 2021 M8 Touring Throttle Butterfly Barely Opening
Post by: robertg on February 07, 2024, 03:24:05 PM
Thanks, I'll put it in gear and see if it changes.

I also didn't mention that I replaced the instrument cluster with a brand new one. I wonder if that might have something to do with this problem?
Title: Re: 2021 M8 Touring Throttle Butterfly Barely Opening
Post by: robertg on February 07, 2024, 04:57:04 PM
I put it in gear and with the clutch pulled in, the butterfly opens wider now. The bike still feels a little sluggish, but it might be my imagination. I have been mainly driving BMWs now that rev a lot quicker than a stock 114 Harley.
Title: Re: 2021 M8 Touring Throttle Butterfly Barely Opening
Post by: Hossamania on February 07, 2024, 05:07:02 PM
At what rpm, gear, and speed are you trying to accelerate?
Title: Re: 2021 M8 Touring Throttle Butterfly Barely Opening
Post by: robertg on February 07, 2024, 05:33:46 PM
Quote from: Hossamania on February 07, 2024, 05:07:02 PMAt what rpm, gear, and speed are you trying to accelerate?
I'm not even riding it now, it is Winter here. I only rode this bike 300 miles last year and wasn't really impressed by its power in any gear. My main bike is a R1200GS BMW, so a stock Harley will seem a little slow compared to the BMW.

I just was moving this bike and a 2019 117 from my heated shop to a cold storage across my yard. They were both sitting beside each other idling. I always thought this bike didn't feel right and in neutral the 117 revs a lot quicker. The 114 just didn't seem to rev that quick, but since the throttle only opens 20% in neutral that explains a lot.

Title: Re: 2021 M8 Touring Throttle Butterfly Barely Opening
Post by: kd on February 07, 2024, 07:15:35 PM
Quote from: robertg on February 07, 2024, 05:33:46 PM
Quote from: Hossamania on February 07, 2024, 05:07:02 PMAt what rpm, gear, and speed are you trying to accelerate?
I'm not even riding it now, it is Winter here. I only rode this bike 300 miles last year and wasn't really impressed by its power in any gear. My main bike is a R1200GS BMW, so a stock Harley will seem a little slow compared to the BMW.

I just was moving this bike and a 2019 117 from my heated shop to a cold storage across my yard. They were both sitting beside each other idling. I always thought this bike didn't feel right and in neutral the 117 revs a lot quicker. The 114 just didn't seem to rev that quick, but since the throttle only opens 20% in neutral that explains a lot.



We're you not riding a built 120 RG before?  Either one will feel a little lazy/soft compared to a cocked and loaded hot rod.   Just sayin.