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This isn't really a "Performance" situation, but I figured with some of the builders that are on here frequently, it would get me the best answers.

Here is my issue:
I have a '12 SG. You can see all the mods in my sig.
After the bike has sat in the garage for a while (about 3 weeks this last time) and/or the weather is colder, I have an issue when first starting the bike. After turning it on, putting it in neutral, and hitting the start button, it fires up almost immediately. As usual, the rpms come up a little, but when they come back down after only a few seconds, the bike will die. When I hit the starter button again, it seems to have to spin twice as long to try and start. When it does catch and try to start, it just... well it sounds like its backfiring through a carburetor. I know it doesn't have a carburetor, but... (I've never heard anyone say "backfired through the fuel injection... Also, it will blow out a pretty good amount of bluish smoke. and this last time it did it, there was a pretty loud clank that came from the inside the motor.
Now after all this, it will start right up after that and go ahead and run.

The only thing else that I can add that may help someone diagnose what may be wrong is a while back a buddy ran into the back of my bike when his brakes failed (coming out of a parking lot). We had to replace the V&H Power Duals and Hi Flow Mufflers. It seems that ever since this, it has had an issue with wanting to cough and nearly die when you first take off. (it did this same thing after the first dyno tune when I originally put them on, but was fixed when the tuned it again). I also have changed the paper filter in the Ventilator to a K&N filter.

I hope someone can give me some advice as to what may be wrong and what I man need to do to solve the problem.

thanks for your time,
MH
 

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Hit it she goes boom
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This isn't really a "Performance" situation, but I figured with some of the builders that are on here frequently, it would get me the best answers.

Here is my issue:
I have a '12 SG. You can see all the mods in my sig.
After the bike has sat in the garage for a while (about 3 weeks this last time) and/or the weather is colder, I have an issue when first starting the bike. After turning it on, putting it in neutral, and hitting the start button, it fires up almost immediately. As usual, the rpms come up a little, but when they come back down after only a few seconds, the bike will die. When I hit the starter button again, it seems to have to spin twice as long to try and start. When it does catch and try to start, it just... well it sounds like its backfiring through a carburetor. I know it doesn't have a carburetor, but... (I've never heard anyone say "backfired through the fuel injection... Also, it will blow out a pretty good amount of bluish smoke. and this last time it did it, there was a pretty loud clank that came from the inside the motor.
Now after all this, it will start right up after that and go ahead and run.

The only thing else that I can add that may help someone diagnose what may be wrong is a while back a buddy ran into the back of my bike when his brakes failed (coming out of a parking lot). We had to replace the V&H Power Duals and Hi Flow Mufflers. It seems that ever since this, it has had an issue with wanting to cough and nearly die when you first take off. (it did this same thing after the first dyno tune when I originally put them on, but was fixed when the tuned it again). I also have changed the paper filter in the Ventilator to a K&N filter.

I hope someone can give me some advice as to what may be wrong and what I man need to do to solve the problem.

thanks for your time,
MH
Sounds like a lean condition.
Scott
 

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12,494 Posts
Good start would be to clean the air idle circuit. Dying on cold idle is the first symptom as the air idle circuit starts to gunk up.

Pull your service manual (if you don't have the manual, and I mean the harley service manual, you need to get one) and go to the section on the idle air circuit and get it cleaned up.
 

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Check for an intake leak. With the engine idling squirt some WD-40 around the intake seals at the heads taking care to not get any spray into the back of the air cleaner. If the engine faulters or RPMs change the seals are sucking air causing a lean condition.
 
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