M8 Hesitation after 117 Inch Stage 4 Install
Thread Starter
|
1st Gear
Joined: May 2013
Posts: 5
Likes: 4
From: Blackfalds
M8 Hesitation after 117 Inch Stage 4 Install
Folks, I'm looking for suggestions as to what could be causing my 2019 Roadglide Special to have, off the line hesitation problems following the install of a Stage 4 117" kit. I had the dealer install stage 1 when purchased, the bike ran perfect when delivered back to the dealer in the fall for the stage 4 install. From the moment I picked the bike up after stage 4 install, the bike immediately had hesitation (and backfire)issues off the line. The dealer has now had the bike for over 2 months. They tell me they have changed sensors, injectors, pulled the street tune and reinstalled but the problem persists. They are presently waiting on a new wiring harness to install. I'm puzzled as to how this may fix the problem being the bike ran perfect prior to tearing down the engine. We are half way through the riding season in Alberta and am getting frustrated not being able to ride this bike while making payments to H-D for a bike I can't ride. My thoughts; if the bike ran fine until stage 4 install, this has something to do with the build.
Any suggestions?
Any suggestions?
Last edited by dave.clarke; Jul 18, 2020 at 03:35 PM.
Ultimate HDF Member
Joined: Oct 2016
Posts: 5,063
Likes: 2,582
From: On my bike!
Yes sir I think you're correct, it's hard to beat a proper dyno tune in the hands of a skilled tuner, I really believe that would fix your issue.
Club Member
Joined: Apr 2016
Posts: 11,500
Likes: 8,336
From: Inland NW
It does sound like it MIGHT be a bad tune, as Quik mentioned. The worst my bike ever ran was with a damned SEPST tune. As luck would have it, the tune the dealer put in my bike after the cam upgrade was the 117 Stage 4 EPA tune. It never back fired, but definitely had a stumble and a hole in the tune after the cam was upgraded.
The PowerVision and a good dyno tune is great. I too have the Smart Tune Pro wide band module, and Jamie at Fuel Moto wrote a tune for my PowerVision to use it.
Good luck
The PowerVision and a good dyno tune is great. I too have the Smart Tune Pro wide band module, and Jamie at Fuel Moto wrote a tune for my PowerVision to use it.
Good luck
Road Captain
Joined: Nov 2009
Posts: 646
Likes: 61
From: Raleigh NC
Hate to say it but there are many stories of unreliable dealer builds. Ongoing problems. I had it on my build years ago. Nothing is more reliable than the factory engine not messed with. If I were doing it today... I'd get the 131 crate engine built at the factory and just dropped in.
Road Warrior
Joined: Nov 2018
Posts: 1,276
Likes: 1,018
From: Eastern Ont.
A buddy and myself both had the smart tuner and now have got rid of them. Mine never ran proper, but buddy had put a S&S 475 in his bike and it would fall on its face off idle quite often, not all the time, but it shouldnt be happening. We went with the PV and both are running much better, no falling on it face.
Trending Topics
Seasoned HDF Member
Joined: Jan 2007
Posts: 5,564
Likes: 3,979
From: Virginia
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Southpaw Super Glide: A Left-Hand-Drive 1979 Harley FXE Built to Fit the Rider
Verdad Gallardo
Tourer
Joined: Sep 2016
Posts: 390
Likes: 52
From: Pearland, TX.
As I understand it being a little hesitant off idle is a characteristic of the 117 Stg IV. Mine was pretty bad off idle (pre-dyno tune with street tuner map) Much better with a dyno tune (SE street tuner) but still noticeable. I then went with a PV and a canned Fuel Moto Map and it was probably a little worse off idle but of course was a beast when in the power band. I also had quite a bit of decel pop. Currently I've had a dyno tune done with the PV and it's back to running pretty smooth throughout but again it doesn't really like just off idle as the power band is basically moved up in the rev range with the Stg IV.
Road Master
Joined: Jul 2020
Posts: 1,195
Likes: 1,346
From: Banana Republic of amerika
I agree that it sounds like the tune. Id get a power vision and have it tuned by a reputable tuner. If warranty is a concern, you could always buy another ecm and use the power vision on the new one keeping the current tune on the current ecm with no traces of having used a non compliant tuner if you need to take the bike in. I personally dont know all the details in doing this, but Ive heard about some folks going this route. Do your research if think this is something your interested in.