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Discussion Starter · #1 ·
Hi.
I have a VRSCDX and have an issue.
When i'm out and making full throttle i notice some sort of lag at 5000rpm. While under it goes as supposed, and when i'm around 5500-6000 it feels like it loose up and start going great again.

So around 5000rpm it feels like it's getting drained.

Anyone have any idea of what it might be?
Already tried to reset everything with a computer but it didn't help.
Now i'm trying with injector cleaner to see if it might help, but nothing so far.

Spoke to one guy who thought it needed to be tuned since it has a different airfilter (KN).
But if i can recall it all started after switching to a new battery. Can't seem to recognize that this problem was before the battery change.

Regards // Kenny
 

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Hi.
I have a VRSCDX and have an issue.
When i'm out and making full throttle i notice some sort of lag at 5000rpm. While under it goes as supposed, and when i'm around 5500-6000 it feels like it loose up and start going great again.

So around 5000rpm it feels like it's getting drained.

Anyone have any idea of what it might be?
Already tried to reset everything with a computer but it didn't help.
Now i'm trying with injector cleaner to see if it might help, but nothing so far.

Spoke to one guy who thought it needed to be tuned since it has a different airfilter (KN).
But if i can recall it all started after switching to a new battery. Can't seem to recognize that this problem was before the battery change.

Regards // Kenny
If that's your bike in your avatar it looks like you have different exhaust pipes also. Did it have the problem before the pipes were changed? Was it tuned then?

It's unlikely K&N filter made much difference. The main advantage is you can clean and re-oil the K&N.

If it was never tuned pick a tuner of your choice. Dyno Jet PCV or Power Commader are 2 good examples.
 

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-MIG
Delilah, my '16 Muscle & Fiona, my '14 Triumph Rocket III Touring
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I run K&N in all my bikes and have never had an issue or required a tune update. However, any other upgrades or tweaks (pipes, etc) has required a tune update. It's possible you need to get your fuel tables fine tuned as mentioned. Without knowing how old, I'd say ensuring you have fresh spark plugs will give you added piece of mind (and you can take a look at how they are burning and see if you do in fact have a fuel mixture issue).
-MIG
 

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Discussion Starter · #4 ·
If that's your bike in your avatar it looks like you have different exhaust pipes also. Did it have the problem before the pipes were changed? Was it tuned then?

It's unlikely K&N filter made much difference. The main advantage is you can clean and re-oil the K&N.

If it was never tuned pick a tuner of your choice. Dyno Jet PCV or Power Commader are 2 good examples.
Hi.
Yes that's my bike and the exhaust is changed for a custom one.

There wasn't any problem when i bought the bike 6 weeks ago, and the exhaust has been one from the day i bought it. But i guess the air/petrol mixture get's wrong since new pipes/airfilter?
 

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Discussion Starter · #5 ·
I run K&N in all my bikes and have never had an issue or required a tune update. However, any other upgrades or tweaks (pipes, etc) has required a tune update. It's possible you need to get your fuel tables fine tuned as mentioned. Without knowing how old, I'd say ensuring you have fresh spark plugs will give you added piece of mind (and you can take a look at how they are burning and see if you do in fact have a fuel mixture issue).
-MIG
Hi Mig.
Thanks for answering. Yeah i guess that might be the issue,more then one have pointed that direction so guess there is a air/petrol issue. What's confusing me thou is the fact that it did run perfect before the swap of battery. Any thoughts of that?
 

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-MIG
Delilah, my '16 Muscle & Fiona, my '14 Triumph Rocket III Touring
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It's possibly a coincidence. Once your bike is started the alternator and voltage regulator take over. The voltage regulator increases or decreases the charging rate of the alternator based on the battery condition. Have you added any electrical components? Regardless, this doesn't sound like your issue if it smooths out at higher RPM's. Definitely points to a fuel-air mixture issue... controlled by the ECU. Once you get her "tuned" let us know how she does. I like to follow folks' issues and resolutions; especially since it could effect me one day.
-MIG
 

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Discussion Starter · #7 ·
It's possibly a coincidence. Once your bike is started the alternator and voltage regulator take over. The voltage regulator increases or decreases the charging rate of the alternator based on the battery condition. Have you added any electrical components? Regardless, this doesn't sound like your issue if it smooths out at higher RPM's. Definitely points to a fuel-air mixture issue... controlled by the ECU. Once you get her "tuned" let us know how she does. I like to follow folks' issues and resolutions; especially since it could effect me one day.
-MIG
I hopefully get her tuned in september and i'll let you know afterwards if that were the issue. Thanks for taking the time to share your thoughts regarding this.
 

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I hopefully get her tuned in september and i'll let you know afterwards if that were the issue. Thanks for taking the time to share your thoughts regarding this.
This is a long shot and a grey area of the J1850 ECM as in fact or fiction. I cannot get a straight answer to it but this is common on many ECMs with a battery disconnect. It's entirely possible but not for sure that if the battery is disconnected for this HD ECM, for a given amount of time , long term fuel trims might be lost. It's a form of block learn, stored in an EPROM chip in the ECM. Saved trims sent to the calibration on each key on event. Basically, If the exhaust was changed it will run on prior learned fuel trims. Battery change might have cleared them and now fueling is off and even with O2 sensors installed to learn new trims over time, it may not ever be right. It takes quite a while for long term trims to develop through the whole calibration, especially in areas of specific rpm like that 5k rpms. A tune is likely in order.
This is the only explanation I can come up with for your symptoms related to battery change.
Ron
 

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Discussion Starter · #9 ·
This is a long shot and a grey area of the J1850 ECM as in fact or fiction. I cannot get a straight answer to it but this is common on many ECMs with a battery disconnect. It's entirely possible but not for sure that if the battery is disconnected for this HD ECM, for a given amount of time , long term fuel trims might be lost. It's a form of block learn, stored in an EPROM chip in the ECM. Saved trims sent to the calibration on each key on event. Basically, If the exhaust was changed it will run on prior learned fuel trims. Battery change might have cleared them and now fueling is off and even with O2 sensors installed to learn new trims over time, it may not ever be right. It takes quite a while for long term trims to develop through the whole calibration, especially in areas of specific rpm like that 5k rpms. A tune is likely in order.
This is the only explanation I can come up with for your symptoms related to battery change.
Ron
Thanks Ron for that answer, seems like we have figured out one possible solution then.
as soons as it's tuned i'll let you all know if it worked or not.
Super thanks to all.
 

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Thanks Ron for that answer, seems like we have figured out one possible solution then.
as soons as it's tuned i'll let you all know if it worked or not.
Super thanks to all.
Possible yes but I cannot confirm if the HD ECM will clear the EPROM with a battery disconnect. My case, running PV I disabled it because I could never get a stable tune with it active. I only use the short term learn during each ride. It resets on each key on event and never gets written to the EPROM.
Ron
 

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Hi.
Yes that's my bike and the exhaust is changed for a custom one.

There wasn't any problem when i bought the bike 6 weeks ago, and the exhaust has been one from the day i bought it. But i guess the air/petrol mixture get's wrong since new pipes/airfilter?
Well if you have the race tuner go in the map section of the forum and look for mileage and performance. It's a map I worked on for a year it'll give a smooth throttle up to about 7500 where the torque falls off. I dyno'd the bike and got 121HP and 91 ft/lbs along with 42 MPG ............... Just a thought
 
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