Issues with lugging/hesitation 2018 Road Glide M8 stage IV kit
#11
02-24-2019, 07:13 PM
Supporter
I've got a 2017 CVO Ltd with stage IV kit that has the very same issues. I'm running aftermarket exhaust that was dealer installed. I've taken it back to the installing dealer without any success, they blame it on the exhaust?? Not sure if I buy into that, as I've talked to others with stock exhaust & same issues. I've learned to ride it a little differently to minimize the flat spot/stumble, riding solo & light it's not so bad, but loaded & 2 up it's a bitch.
#12
02-24-2019, 07:42 PM
Advanced
I've got a 2017 CVO Ltd with stage IV kit that has the very same issues. I'm running aftermarket exhaust that was dealer installed. I've taken it back to the installing dealer without any success, they blame it on the exhaust?? Not sure if I buy into that, as I've talked to others with stock exhaust & same issues. I've learned to ride it a little differently to minimize the flat spot/stumble, riding solo & light it's not so bad, but loaded & 2 up it's a bitch.
He had it put on a dyno and it makes less torque and hp than a stock M8 until the higher rpms where it makes quite a bit more.
The CNC heads, larger throttlebody and cam all contribute the loss of low end torque.
One of the reasons I only have a stage 2 setup in my 103.
#13
02-24-2019, 10:33 PM
My dad had stage 4 installed on his SGS with all HD parts including the exhaust and has the same issue.
He had it put on a dyno and it makes less torque and hp than a stock M8 until the higher rpms where it makes quite a bit more.
The CNC heads, larger throttlebody and cam all contribute the loss of low end torque.
One of the reasons I only have a stage 2 setup in my 103.
He had it put on a dyno and it makes less torque and hp than a stock M8 until the higher rpms where it makes quite a bit more.
The CNC heads, larger throttlebody and cam all contribute the loss of low end torque.
One of the reasons I only have a stage 2 setup in my 103.
if you voided your drivetrain warranty... well then sticking with the SE Tuner is irrelevant. Upgrade to a PowerVision and get the engine properly tuner with the fatcat.
Those are your 2 best options depending on the status of your warranty and how important it is you. My recommendation (based on experiencing 3 sumped stage IV M8s) is keep your warranty intact if you haven’t lost it already. Its very possible you might find a need for it in the future.
#14
02-24-2019, 11:39 PM
Outstanding HDF Member
Your best bet is putting a stock header and exhaust back on and seeing if the problem persists. If someone brings me a lugging hesitating bike i will bring the intake/exhaust/and tune back to stock to be 100% sure there are no problems with the big bore kit. Always troubleshoot. Add one thing at a time until you can replicate the hesitation and lugging. It could be one problem or multiple problems adding up and those are tough to narrow down. If its a problem with the motor you want to know as soon as possible. Techs make mistakes and rush sometimes. Good luck.
#15
02-25-2019, 12:15 AM
Cruiser
Spent over 7k on a Stage IV kit installation in my 2018 RGS, just got around 500 miles since its installation. I have been having hesitation issues off the line and lugging until it gets going. I had my local dealer do the install so my warranty would remain intact since it's a brand new unit. I also put a D&D 2 into 1 exhaust on this unit. Well I took it back to the dealership thinking perhaps it was an minor adjustment that may be needed to get the correct tuning. In a nutshell the service writer told me I would just have to deal with it because the tuner is the issue and if I put the proper tuner in the bike and something happened to the motor Harley Davidson wouldn't warranty the motor. My blood immediately began to boil, but before I went over the edge I was thinking I'd ask if perhaps anyone else has had this issue. Would Harley really sell a kit that wouldnt operate properly and then tell me it will cost more money to put in a new tuner and the new tuner will void your warranty. I am floored that when they were selling me the kit and the higher upgrades, I wasn't informed of this and now that I'm already $7000 deep into this build I'm told I have to accept the fact my bike isn't going to run properly or spend more money in order to avoid my warranty if something does go wrong.
I can tell you I want to go in there full on militant style and raise some hell, but that will surely not end well for anyone or get my problem resolved satisfactorily. Any advice or experiences that I can draw some knowledge from would be greatly appreciated
I can tell you I want to go in there full on militant style and raise some hell, but that will surely not end well for anyone or get my problem resolved satisfactorily. Any advice or experiences that I can draw some knowledge from would be greatly appreciated
this WILL solve the tuning issues, it will not change the stage 4 low rpm weakness, the stage 4 kit starts making its power about 3400 rpm.
I have a 2018 heritage 114 with stage 3 (now 117) and D&D exhaust screamin eagle tuner and smart tune pro with wide band sensors, my bike runs VERY well
https://mstore.harley-davidson.com/store/smart-tune-pro-automatic-tuning-module
Last edited by Hardcase61; 02-25-2019 at 12:38 AM.
#17
02-25-2019, 06:19 AM
Club Member
#18
02-25-2019, 06:25 AM
Club Member
Spent over 7k on a Stage IV kit installation in my 2018 RGS, just got around 500 miles since its installation. I have been having hesitation issues off the line and lugging until it gets going. I had my local dealer do the install so my warranty would remain intact since it's a brand new unit. I also put a D&D 2 into 1 exhaust on this unit. Well I took it back to the dealership thinking perhaps it was an minor adjustment that may be needed to get the correct tuning. In a nutshell the service writer told me I would just have to deal with it because the tuner is the issue and if I put the proper tuner in the bike and something happened to the motor Harley Davidson wouldn't warranty the motor. My blood immediately began to boil, but before I went over the edge I was thinking I'd ask if perhaps anyone else has had this issue. Would Harley really sell a kit that wouldnt operate properly and then tell me it will cost more money to put in a new tuner and the new tuner will void your warranty. I am floored that when they were selling me the kit and the higher upgrades, I wasn't informed of this and now that I'm already $7000 deep into this build I'm told I have to accept the fact my bike isn't going to run properly or spend more money in order to avoid my warranty if something does go wrong.
I can tell you I want to go in there full on militant style and raise some hell, but that will surely not end well for anyone or get my problem resolved satisfactorily. Any advice or experiences that I can draw some knowledge from would be greatly appreciated
I can tell you I want to go in there full on militant style and raise some hell, but that will surely not end well for anyone or get my problem resolved satisfactorily. Any advice or experiences that I can draw some knowledge from would be greatly appreciated
When I was looking at doing a kit on my Low Rider, I was considering both the stage 3 and 4 kits, but decided to go with the stage 3. The 4 made a lot more power, but as said, it was only up high where I only touched occasionally. The S3 made considerably more power down low where I live. Im very happy with it.
Unfortunatly there doesn’t seem to be very much you can do. I doubt a PV tune will change the curve dramatically, I’m sure it would improve things, but the nature of the kit is built for high rpm power.
The stage 4 kit uses the same 11:1 pistons as the S3 kit, so Maybe put your stock heads and TB back on and put a SE8 498 cam from the S3 kit in. But you’re talking a lot more labor $$.
Sorry for your troubles
Last edited by Mchad; 02-25-2019 at 06:44 AM. Reason: added some actually relevant info.
#19
02-25-2019, 07:46 PM
Road Master
If it was mine I would go ahead and get it tuned where it would run good and not worry about the warranty. You want your bike to run good after spending that much money. I would not bring it back to that dealer because they just want to use screamin eagle parts.
I just put a fp3 on my 2018 and I may have voided the warranty, but I don't care.
I just put a fp3 on my 2018 and I may have voided the warranty, but I don't care.
Last edited by Gary1; 02-25-2019 at 07:51 PM.
#20
02-25-2019, 08:04 PM
HD EFI Guru
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