FLI: Stage 2 and dyno'd, sputtering on takeoff
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Cruiser
Joined: Feb 2020
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From: TX
FLI: Stage 2 and dyno'd, sputtering on takeoff
Hello! Looking for some insight/feedback/thoughts if possible.
So: 2024 Hydra Glide Revival, stage 2 with STAR 30/30 cam, dyno'd at Harley dealership.
Bike runs GREAT now, except on takeoff. From a stop, or even from idle RPMS with clutch pulled in while coasting, if the engine idles down, there's a bad delay in the throttle response when you roll back on. I've been riding 20 yrs, MULTIPLE bikes of all kinds, NEVER had this much problem taking off reliably/comfortably. It basically feels like a delay/loss of power, then depending on how much throttle you roll into, a sudden surge that could genuinely cause a loss of control. If I add throttle from a stop with the clutch pulled in, the bike will actually almost die out, to the point it's tripped the engine light like when your battery is too weak to start the bike. If I keep the throttle input, after it sputters and almost dies, it'll then ramp up rapidly to whatever the throttle is actually set for. It's just like there's this huge delay in intake response, followed by a barely-controllable surge in RPMs. I'm learning to modulate it more, and feathering the **** out of the clutch to keep actual power transfer under control, but it's something I'd REALLY prefer to smooth out in the tune if possible.
Talked to tuner and mechanic, they said it's normal and due to the cam and tune, causes it to need to kind of "spin up" before releasing the clutch. I'm not sure I buy it. I feel like if they set the TBW to more of a 1:1 ratio of input to intake response, it may remove the delay and make for more predictable takeoffs. I'm ready to take it to a different tuner up the road, but want to see if that's even warranted, or if this is normal and is just something I have to get used to.
Thanks in advance!
So: 2024 Hydra Glide Revival, stage 2 with STAR 30/30 cam, dyno'd at Harley dealership.
Bike runs GREAT now, except on takeoff. From a stop, or even from idle RPMS with clutch pulled in while coasting, if the engine idles down, there's a bad delay in the throttle response when you roll back on. I've been riding 20 yrs, MULTIPLE bikes of all kinds, NEVER had this much problem taking off reliably/comfortably. It basically feels like a delay/loss of power, then depending on how much throttle you roll into, a sudden surge that could genuinely cause a loss of control. If I add throttle from a stop with the clutch pulled in, the bike will actually almost die out, to the point it's tripped the engine light like when your battery is too weak to start the bike. If I keep the throttle input, after it sputters and almost dies, it'll then ramp up rapidly to whatever the throttle is actually set for. It's just like there's this huge delay in intake response, followed by a barely-controllable surge in RPMs. I'm learning to modulate it more, and feathering the **** out of the clutch to keep actual power transfer under control, but it's something I'd REALLY prefer to smooth out in the tune if possible.
Talked to tuner and mechanic, they said it's normal and due to the cam and tune, causes it to need to kind of "spin up" before releasing the clutch. I'm not sure I buy it. I feel like if they set the TBW to more of a 1:1 ratio of input to intake response, it may remove the delay and make for more predictable takeoffs. I'm ready to take it to a different tuner up the road, but want to see if that's even warranted, or if this is normal and is just something I have to get used to.
Thanks in advance!
Seasoned HDF Member
Joined: Apr 2015
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Likes: 5,337
This issue started after the dyno? If so, I sense that you don’t want to take it back to the dealership and have the tuner ride the bike? Which tuner, SEPST? If so, can a Star 30/30 cam be tuned properly with a SEPST?
Last edited by GalvTexGuy; Yesterday at 04:19 PM.
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Cruiser
Joined: Feb 2020
Posts: 205
Likes: 123
From: TX
My current plan is to take it to this other place that's newer on the local scene but is dead serious about their presence, and let their tuner ride it to see what he thinks. BUT, I wanted to run it by here first to see if my issue is a common thing for people going to stage 2 with a different cam, so I could save myself the embarrassment of the tuner just saying I don't know how to ride lmao
Last edited by goodguybiker; Yesterday at 04:32 PM.
Grand HDF Member
Joined: Jul 2007
Posts: 3,745
Likes: 8,580
From: Bates County MO
Find out what tuner was used. They should be able to supply you with a license (or interface device), and a copy of the original map + the tuned (final) map. Once that's complete, we can look at the map and maybe see what's happening.
Club Member
Joined: Apr 2016
Posts: 11,637
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From: Inland NW
I called and asked about bringing it back in for the tuner to check out, but the rep at the counter said it's a common adjustment people have to get used to, he had his bike worked on by the same guy and he had to learn it as well. So, I dunno...
My current plan is to take it to this other place that's newer on the local scene but is dead serious about their presence, and let their tuner ride it to see what he thinks.
My current plan is to take it to this other place that's newer on the local scene but is dead serious about their presence, and let their tuner ride it to see what he thinks.
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