Am Interested in Opinions, already know the answer.

[Buellbloke]

Bought a 2015 Dyna FXDF 103 Fat Bob from Edinburgh Harley towards the end of lockdown. Only saw it in pictures and video.
Had about 6k miles, 1 previous owner and the Originals warranty.
Came with V&H Big Radius standard baffle and a Stage One Harley tune. A Screaming Eagle Heavy Breather with rainsock.
Otherwise it was standard.
Wicked popping and banging on the overrun, so much it often attracted the attention of the old bill, not enough to get a pull, but enough for them to show they were taking notice.
A few months into ownership on longer weekend blasts of around 120miles found the bike to be revving high coming down the gears, even with the clutch engaged.
Occassionally it would cut out at low speed, start again, maybe be ok or it could cut out again then clear.
This happened on a few occassions until I sorted it, at first temporarily then permanently.
Anyone fancy a diagnosis on both the popping and banging and the completely seperate running issues?
As a partial clue a dealer can fix the running issues for what was about £80, then they can fix it again in a few months or longer depending how long and how often you ride. You can fix it permanently for a tad more

 

[Halal Tim]

They all do that, sir.

 

[Buellbloke]

They all do that, sir.

A lot do in the UK as climate does seem to have an effect.

 

[watchman]

Hard to tell without hands on Popping on the overrun is either exhaust air leak or symptoms of lean mixture and it sounds like the s/e flash tune which are notoriously poor when used over here may be partly to blame probably cured with a decent dyno tune using direct link tuner or a power vision both far better to harleys crap as air density temperature ect all come into play when doing a tune i have seen kit set up over there run like a donkey until redone here and the s/e tuner binned
as for the running issues hmm sounds like an inlet air leak which is easy to test for or the tps is twatting about both will cause the revs to stay high on changes another another one is the manifold sensor which can play up got any codes ?

 

[softail898]

My guess is a manifold air leak.

 

[watchman]

If we get this right without hands on i will be buying a lotto ticket tomorrow….

 

[Buellbloke]

If we get this right without hands on i will be buying a lotto ticket tomorrow….

This was an old problem rectified, you are quite correct about a harley tune, they are quite worthless. Only those that don't know trust harley dealers to map their machines. They are controlled by emissions so are unable to map a Stage One without implimenting the same conditions that applied to your original factory exhaust system. Also as they did not at that time possess maps specific to V&H products or any products not their own they could only supply maps made for Screaming Eagle products/slip on's. Any tuner not made by harley will supply a more richened map and eliminate popping on the over run, that will make your bike run cooler sweeter and more engine friendly, though not necessarily faster. A weak map can actually be a tiny bit faster map, certainly if you use a V&H Fuel Pack 3. Though the V&H Fuel Packs do allow you to edit some of the pop back in as well as edit things like your tickover. You may have to decide whether you want to de-emission your bike and make it run at its most healthy or stick with a weak map that can over time potentially damage your engine. Its not that harley don't care its just their hands are tied.
A dyno can provide the absolute best outcome though not all dyno tuners are equal.
On a side note now that harley have abolished its "Screaming Eagle Super Tuner Pro", what a piece of dog poop that was, a con at best, almost unusable by the end user. You needed a laptop, a dongle then had to edit the fuel map, ride the bike and edit it some more.
I believe most dealers are now using Colourtune by Power Commander, I do not know if they are using healthy maps or still edited for emissions versions?

So that's the popping on the over run dealt with
Now the shitty running, so far your cold on that one except for the sensor part, as yes thats to blame but not how your think.

 

[watchman]

The only thing i can think of is years ago i brought an s+s crate lump for my fxdxt it came with their ist ignition to plug in and its own loom to connect to the stock wiring and it had a temperature sensor fitted to one of the heads and a knock sensor on the top motor mount when i put it on the dyno to jet it and sort discs on the supertrapp she got a tad hot and then the ignition started to twat about between maps and all sorts turned out the temp sensor sensed the head heat and the ignition kept pulling the curve to save the lump from cooking and i am wondering if your fuel injections doing the same holding revs up to cool lump poss caused by s/e tune ?

 

[Buellbloke]

Nope, its an age old problem certainly been around since the Evo, early twin cams the 1450's had it worse I believe. Am not 100% but believe the IAT sensor on early 1450's was in the mouth of the inlet. On later twin cams they moved it into the left inlet which meant it got washed with fuel

 

[watchman]

So where do they put it to cure the problem ? In the air filter inlet before the injectors ?

 

[Buellbloke]

So where do they put it to cure the problem ? In the air filter inlet before the injectors ?

Don't believe I've mentioned the problem except it has something to do with the IAT sensor.
You never suffered with lumpy starts? Low speed cut outs? revs hanging clutch depressed? Just smooth sailing.
Never noticed an issue with my early 2008 fatbob, had a Power Commander on that thing, no O2 sensors the Power Commander couldnt work with them, made for a strange tickover. No issues on that one.

 

[watchman]

Sprayed an iat with carb cleaner on a softail to clean it when it had been stood for 6 months and it ran better so i must have been on right track and there was a fix by moving it by the sound of it he would clean yours then next time put a new one in the air filter before the injectors leaving the old one as a hole plug glad all my stuff is carb only now
Ps cancelling lottery ticket…

 

[softail898]

Ps cancelling lottery ticket…

 

[Buellbloke]

If it gets fouled by anything then it can certainly cause a whole host of issues. When I posted the cure on a UK social media group all the harley aficionados had to say was, we don't care, we don't want to know, our bikes are perfect as they are. USA owners are more keen to address the issue. The problem lays in the fact a vast majority of harley owners pay for servicing, pay for others to do any work on their machines, too few have the confidence to take a drill to their beloved machines. In the USA lots are fitting their own cam upgrades and f*cking up their handle bar upgrades so I guess its understandable.
Harley hit their desired young peoples market with the new M8 Fatbob, Street bob and Low Rider S. What they didnt account for was the amount of claims for knackered machines ridden to the red line in every gear, thrashed and wheelied to within an inch of their mechanical lives. The new issues 4 valve heads would cause their oil pumps and other mechanical related parts including the compensator, the excess crankcase pressures, the sumping, how emissions would screw this engine over. I digress, harley has made an attempt to address the above issue on the new M8's but due to budgets the new part is failing too! So am getting ready to experience what I originally posted on my new M8 Street Bob too! Am keeping a curious eye on it.

 

[watchman]

Looks like you joined the right club in here in november a lot of the lads are avid spanner merchants tuners and builders have a look at the thread “what have you done to your bike today” it will give you an idea

 

[softail898]

Looks like you joined the right club in here in november a lot of the lads are avid spanner merchants tuners and builders have a look at the thread “what have you done to your bike today” it will give you an idea

Make a Cup of Coffee, it’s a Long Thread.

 

[Gez]

Harley hit their desired young peoples market with the new M8 Fatbob, Street bob and Low Rider S. What they didnt account for was the amount of claims for knackered machines ridden to the red line in every gear, thrashed and wheelied to within an inch of their mechanical lives. The new issues 4 valve heads would cause their oil pumps and other mechanical related parts including the compensator, the excess crankcase pressures, the sumping, how emissions would screw this engine over.

Sounds like I should get rid of my FXLR Low Rider, they must be a really crap bike?

 

[Buellbloke]

Sounds like I should get rid of my FXLR Low Rider, they must be a really crap bike?

It's a gorgeous bike even the Dyna though she's a bit too raked out at the front end the Dyna (still got old skool cruiser in her). That 110 motor sure does run hot! I've got an M8 114 Street Bob its the same engine even if you have the 117 basically its the same motor. She just needs some basics done as soon as you obtain her. Vent the crankcase and fit a stage one asap including a non catalytic exhaust pipe but not with a harley tune.
I fell out with a facebook group that turned out to be an OZ bike shop over speculations that the early oil pumped M8's pre 2020 could be cured of most sumping issues just by cheaply venting the crankcase. (Well didnt really fall out just roughened their heckles) They used some fancy word for foaming oil that is basically the response of too much crankcase pressure and a modicum of vaccume. They claimed all sorts about the new oil pump and why really you might as well change your cam, camplate and followers in the process of changing to the new pump. That and you should fit a new compensator their one for over $700 bucks. Well they would wouldn't they they're a bike shop. The new pump helps with scavenging but does not cure sumping as the foaming oil is still present unless the pressures are vented. Venting alone can make a massive difference to the original pump, as for the sumping you keep an eye on it. Ron had an original pump when he vented his bike.

 

[Gez]

The M8 issues have been thoroughly debated elsewhere on this forum so won't go there on this thread. Save to say I'm happy to leave it (the engine anyway) standard, apart from V and H 3" (d.i.y. silenced mufflers). Think you're right though, if they're continually thrashed, "over tuned" etc, they're gonna give trouble.........

 

[Buellbloke]

The M8 issues have been thoroughly debated elsewhere on this forum so won't go there on this thread. Save to say I'm happy to leave it (the engine anyway) standard, apart from V and H 3" (d.i.y. silenced mufflers). Think you're right though, if they're continually thrashed, "over tuned" etc, they're gonna give trouble.........

Can I assume you at least vented the crankcase??
Done at 300 miles from new.
Has a non return valve inline to retain what little vacumme is present and a pod filter on the end.
Barely noticeable once the fake oil tank/side cover is re installed.
£20 and a little bit of effort to cure excess crankcase pressure and the potential for sumping eliminated.