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Discussion Starter · #1 ·
My bike has trouble Starting, what is mean is it cranks and cranks and on and on but doesn't wanna start.
And then it suddenly starts and when it does start it doesn't wanna stay running, it runs for about 5-10 seconds and shuts off unless i give it some gas. when i hold it between 2.5 to 5k rpm it stays running some times the revs start playing.

If anyone can explain how, id add a video showing the issue

things I have done so far are : New battery,
Took apart the throttle body and cleaned it,
New spark plug.(the old one when I took it apart had smelled of gas and seemed black at the tip)
New air filter.
Valve clearance was checked and is fine.
Fuel pump was presure checked and is fine.


Could anyone help me work this out ?
Any info would help.
 

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What year is your Duke?
Changed the fuel filter?
Ignition checked? sparks well?
It sounds to me like a fuel issue though.
 

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Duke 390
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Discussion Starter · #6 ·
What year is your Duke?
Changed the fuel filter?
Ignition checked? sparks well?
It sounds to me like a fuel issue though.
Ignition I haven’t checked yet as I don’t really know how, I did change the spark plug tho.
Fuel filter I haven’t check.
The year is 2015 1st gen.
I am leaning towards a faulty fuel injector, what do you think?
 

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Yes, the fuel filter sits under the tank included, if you want, in the fuel pump/float unit.
Easy to change out but do get a new 1 first as these are not a simple run through 1 side in, 1 side out filter, it has 3 connections.
It can be a (partially)blocked injector. See Youtube for cleaning instructions you could try.
Good luck (my 390 is also from 2015)
 

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Discussion Starter · #10 ·
Yes, the fuel filter sits under the tank included, if you want, in the fuel pump/float unit.
Easy to change out but do get a new 1 first as these are not a simple run through 1 side in, 1 side out filter, it has 3 connections.
It can be a (partially)blocked injector. See Youtube for cleaning instructions you could try.
Good luck (my 390 is also from 2015)
I think I’ll change the injector, I’ll update as soon as I did
 

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Yes, the fuel filter sits under the tank included, if you want, in the fuel pump/float unit.
Actually, on my 2017 Duke, the fuel filter is a separate entity from the fuel pump. It's connected to the pump by a rigid quick disconnect hose.

Edit: I just realized the bike in question is 2015, sorry for putting my foot in my mouth. @theduke3900 , please follow @KTMasean 's advice.
 

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Discussion Starter · #12 ·
Do
Yes, the fuel filter sits under the tank included, if you want, in the fuel pump/float unit.
Easy to change out but do get a new 1 first as these are not a simple run through 1 side in, 1 side out filter, it has 3 connections.
It can be a (partially)blocked injector. See Youtube for cleaning instructions you could try.
Good luck (my 390 is also from 2015)
Do you think by any chance the ignition coil may be faulty ?
 

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Not very likely as in general the coil will either work or it does not.
If able to start with the throttle opened a little I am more of the opinion it is a fuel (supply) issue.
If you can easily replace the injector if only to try, by all means.
Please bear in mind though that if this is the culprit there is a reason for the injector to get blocked and the fuel filter is the one to prevent this from happening.
In other words, when replacing the injector make sure you install a new fuel filter as well because otherwise the new/replacement injector could get blocked in no time as well.
If you have a good motorcycle shop nearby, take out the injector and have them check this for functionality.
There are even tools (like the one from Motion Pro; Fuel Injector Cleaner Kit for ND - Motion Pro) to clean the injector.
In countries where I ride you some times end up buying a litre of questionable fuel in a bottle along the roadside.
The fuel filter will filter out most of the solids and prevent your injector from getting blocked up.

A mechanic is able to check if there is an issue with the ignition coil or you can take out the spark plug, plug it into the wire running from the ignition coil, hold the threaded part of the plug to mass (-) and push the start button while watching for sparks between the electrodes of the plug.
If these come continues and strong/bright your ignition coil most likely works fine.
Caution: while holding the spark plug to mass, make sure you do not touch any metal part of the plug, wear a rubber glove to prevent getting an electric shock.

Good luck.


Do

Do you think by any chance the ignition coil may be faulty ?
 

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Discussion Starter · #14 ·
Not very likely as in general the coil will either work or it does not.
If able to start with the throttle opened a little I am more of the opinion it is a fuel (supply) issue.
If you can easily replace the injector if only to try, by all means.
Please bear in mind though that if this is the culprit there is a reason for the injector to get blocked and the fuel filter is the one to prevent this from happening.
In other words, when replacing the injector make sure you install a new fuel filter as well because otherwise the new/replacement injector could get blocked in no time as well.
If you have a good motorcycle shop nearby, take out the injector and have them check this for functionality.
There are even tools (like the one from Motion Pro; Fuel Injector Cleaner Kit for ND - Motion Pro) to clean the injector.
In countries where I ride you some times end up buying a litre of questionable fuel in a bottle along the roadside.
The fuel filter will filter out most of the solids and prevent your injector from getting blocked up.

A mechanic is able to check if there is an issue with the ignition coil or you can take out the spark plug, plug it into the wire running from the ignition coil, hold the threaded part of the plug to mass (-) and push the start button while watching for sparks between the electrodes of the plug.
If these come continues and strong/bright your ignition coil most likely works fine.
Caution: while holding the spark plug to mass, make sure you do not touch any metal part of the plug, wear a rubber glove to prevent getting an electric shock.

Good luck.
Thank you sir ! Very informative.
 

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Caution: while holding the spark plug to mass, make sure you do not touch any metal part of the plug, wear a rubber glove to prevent getting an electric shock.
Can confirm: it is NOT fun to be shocked by the ignition coil. It's not extremely painful, nor is really dangerous like a normal AC shock is, but it's very unpleasant.
 

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My bike has trouble Starting, what is mean is it cranks and cranks and on and on but doesn't wanna start.
And then it suddenly starts and when it does start it doesn't wanna stay running, it runs for about 5-10 seconds and shuts off unless i give it some gas. when i hold it between 2.5 to 5k rpm it stays running some times the revs start playing.

If anyone can explain how, id add a video showing the issue

things I have done so far are : New battery,
Took apart the throttle body and cleaned it,
New spark plug.(the old one when I took it apart had smelled of gas and seemed black at the tip)
New air filter.
Valve clearance was checked and is fine.
Fuel pump was presure checked and is fine.


Could anyone help me work this out ?
Any info would help.
[/QUOT
Hi
Maybe check your fuel filter
and clean or change your injector
 

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Discussion Starter · #17 ·
Is it the symptoms of a bad fuel filter? I have changed the injector and nothing has changed
 

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Is it the symptoms of a bad fuel filter? I have changed the injector and nothing has changed
Did you read KTMasean's response? Please re-read it.
Please bear in mind though that if this is the culprit there is a reason for the injector to get blocked and the fuel filter is the one to prevent this from happening.
In other words, when replacing the injector make sure you install a new fuel filter as well because otherwise the new/replacement injector could get blocked in no time as well.
 

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Sounds like fuel to me. If your bike has been sitting for the winter, you may now have bad fuel or water in your fuel. I'd definitely start with changing the fuel filter and just getting some fuel out of the bottom of the tank if not just fresh gas period.
.
 
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