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Discussion Starter #1
Hey everyone, purchased a 2017 750 last Saturday. My first Harley Davidson and first bike after about 30 years.

When I got it home, I has some issues starting it. Pressing the start button would do nothing. I'd play with it for a bit, in and out of neutral, kickstand up/down, clutch in/out, then it would start. That issue seemed to have went away because it's ok now.

My main issues is it's jerking/bucking while I'm holding the throttle steady doing about 25 MPH or under. I've only been riding in the neighborhood until I get used to the bike so I don't know how it does at higher speeds.

Is this normal during a break in? I tried up and down shifting to different gears but it doesn't help. It just jerks and bucks down the road, unless I'm accelerating, then it's fine.

Any insight is appreciated.
 

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This is exactly what has been happening with my bike for months. I can't figure out why mine does it. I just cope with it now because I really don't want to take it to my HD dealer and get screwed with their high prices. My model wasn't a model that had the pump inlet recall either, but it still seems like it has something to do with the fuel system. If you find anything out on it please let me know because more than likely that's the same problem with mine.
 

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The only logical thing I can come up with is the lag and leap issue with the xg's... But I looked up my VIN and my 2015 model wasn't one of those that were recalled. The solution would be to replace the fuel pump, but I don't understand why it would be in that "lag and leap" category but my model wasn't one of those that were recalled. I know if I take it into the dealership they will tell me it is because of the modifications I have done to the bike, so I'm kinda at a crossroad.
 

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And I know they 2017 models wouldn't be in the recalled category so it makes me think it may be something different... Hmm..
 

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Discussion Starter #6
At first I thought it was maybe a fuel starvation issue, but it clears up while accelerating. So if it wasn't getting fuel, it seems like giving it throttle would make it worse.

It's only when trying to keep a steady speed. I'm having someone else take it for a ride tomorrow just to make sure it's not me. And I will call the dealer.
 

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Same here man... Everything you are describing is happening with mine. If I want to get up and go in a hurry the bike runs perfect, but if I want to just cruise around town 25-30 mph then it sputters. Does yours do it when cornering too? Like trying to keep a steady speed in a corner and it starts sputtering? Mine does it all of the time whether my tank is full or empty. It seems to me like it runs better without as much sputtering when the weather is warming in like the 70's range, but it may not have anything to do with it... Either way, it still does it and apparently it isn't normal so if you take it to your dealership please tell me what they say is wrong with it.


Thanks!
 

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for me I just bought the fp3 and remapped bike. It runs smoothly with no throttle now

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I also bought an fp3 and a v&h VO2 high flow filter and remapped it with fp3 and it still sputters at low speeds.
 

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Not yet, I am trying to gather as much info before I flash it. I haven't been able to ride it for an extended amount of time in the past week.
 

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Discussion Starter #12
Just a quick update. I had someone else ride my bike tonight just to make sure it wasn't me. He said it felt like a misfire. The RPM's aren't fluctuatig, so the clutch isn't slipping. It really does feel like a misfire until you give it throttle. And now it's popping and back firing at times.

I'm calling tomorrow to make an appointment to bring it in. I love the bike but so far this isn't a great first impression. Although the actually buying experience was awesome.
 

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My RPM's fluctuate when my bike is at idle, and when I start to ride from a stop I have to roll the throttle about a quarter of the way for my bike to get past the "bogging" sound and then it very quickly switches from bogging to BAM normal and off we go. It's friggin' weird and the fp3 and high air flow filter isn't fixing it... I'm in the process of gathering data for the auto tune.. Maybe that will do some help.
 

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My RPM's fluctuate when my bike is at idle, and when I start to ride from a stop I have to roll the throttle about a quarter of the way for my bike to get past the "bogging" sound and then it very quickly switches from bogging to BAM normal and off we go. It's friggin' weird and the fp3 and high air flow filter isn't fixing it... I'm in the process of gathering data for the auto tune.. Maybe that will do some help.
Playing with fire kid... About to blow something up past the point of no return... And you will be stuck holding the bill and the pieces... Sounds like the data should have been collected before any parts were thrown at it and needed to be fixed first... When you get a data log link it here so I can try and decipher what is going on...
 

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Just a quick update. I had someone else ride my bike tonight just to make sure it wasn't me. He said it felt like a misfire. The RPM's aren't fluctuating, so the clutch isn't slipping. It really does feel like a misfire until you give it throttle. And now it's popping and back firing at times.

I'm calling tomorrow to make an appointment to bring it in. I love the bike but so far this isn't a great first impression. Although the actually buying experience was awesome.
On a 2 cylinder, depending on the severity of that misfire, is going to be make or break on that motor.... You will have no power, no speed, knocking and pinging, a crap ton of issues.... A slight misfire could be causing some of these issues I read you had posted, but the others, sounds like there is more to this than someone is letting on or describing...

The clutch has nothing to do with the RPMs fluctuation at all whatsoever.... if it were slipping it would feel like torque steer or exactly that, a slip and then the power catches.... Its either starving for air or fuel, possibly spark but I doubt it... From the vague descriptions... Decel pop and back firing is common when unburned fuel is not being burned properly, along with the possibility of running too lean/rich, and there is a ton of it happening with factory exhausts, but due to the glass packs, restrictive resonators, baffles etc you can't feel or hear it as with performance/open exhausts... Air/Fuel ratio must be as close to stoich/14:1 as possible, but that is in a utopian society and doesn't exist....

Let me ask this, what modifications have been done to this thing? And was it retuned properly thereafter?
 

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i had that also.
the dealer replaced my fuel pump, and it stopped
 

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I'm going to check spark plugs tomorrow and see how they look.. If they are bad i'll change them and see if that fixes anything. I was thinking fuel pump too top, how much did your dealer charge you for parts and labor? Just so I can get a general $ amount in my head if I have to resort to getting a new one.
 

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I'm going to check spark plugs tomorrow and see how they look.. If they are bad i'll change them and see if that fixes anything. I was thinking fuel pump too top, how much did your dealer charge you for parts and labor? Just so I can get a general $ amount in my head if I have to resort to getting a new one.
Or just ignore my advice yet again.... Top just came in and said his piece, and I have been saying it all along... Starving for air, fuel, or spark, that's it combination thereof... Suck bang press blow or for the techs Intake Compression Power and Exhaust strokes... And every dealer and tech comes up with their own labor/diagnosis rates. Yes there is book hours for labor dealing in values of .1 / 7 mins an hour... They will make sure they get paid regardless... The $$$ you spent on mods instead of fixing what's wrong with it would have saved you tons, not the other way around...

Like I said, you are playing with fire kid... Run lean for one second at high RPMs under a full load and watch the sparks fly.... On a turbo/super charged car it's even worse...
 
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