No Fire sometimes.

[Captjohn]

Let's see if anyone has any ideas on this. 06 K-9, 117ci. Starts up and runs like brand new. Go out next day, hit the starter, engine turns over, no fire at plugs, Try over and over...nothing. Go out hour later and it fires right up like brand new. This has happened a couple of times. I thought it was a problem with gas cap(vapor locked)but now I'm not sure since I checked fire. Bike has Wire Plus Kit and heavy-duty switch installed.

 

[blacktopper]

Check the jst connector to the ignition module I had the power wire pin back out once and it would act like that

 

[Captjohn]

Thanks for the tip! I'll check it out.

 

[Brew]

Inspect and clean your crank sensor also...

 

[bruce]

check wires at battery, I had a main ground wire broken just before connector at battery. at first look it looked fine because of how wires are in there, but at closer look it was broken clear thru. bike would run fine and then not start, it was like this for awhile before I found.

 

[droden59@gmail.com]

not firing

I was riding I gunned it then let off and it just dies and now it isn't firing.My battery ends were loose and battery act low.Will that cause it not to fire ?

 

[BadDawg Bill]

You got to blow harder in the breathalyzer...

 

[Davis296]

This is gonna sound crazy, but this works on my '04 mastiff. Key on, arc the coil to ground. BOOM out the exhaust, and it fires right up and usually runs/starts all day. If anyone can explain it I'd love to hear it. I've swapped coils, have WP374, done it for years...No rhyme or reason.

 

[Guillaume]

Thanks for this treat because I have the same problem with my 07 K9 yesterday .
Checking out what your guy, s suggest. :2thumbs:

 

[Sven]

Key on, arc the coil to ground. BOOM out the exhaust, and it fires right up and usually runs/starts all day. If anyone can explain it I'd love to hear it.

Coil acts like a set of points or a computer being on/off or 1's and 0's mean the same thing. On is a condenser call it. Off or Ground it makes spark or jumps to ground is a stored energy source is a coil. So key on, sparks both cylinders at the same time, one has fuel left over and keyboom, starts up where the piston has to be past TDC and fires off with a spark.

No way would the spark fire on the piston that is before TDC? Then the spark would push the piston back down and fire backwards. But it can't climb up to compress, you ground the coil. It has to be at the power side [ATDC] so that is a closed or sealed cylinder to cause the 'sealed' air, not compressed air to fire.

Make sense?

My battery ends were loose and battery act low.Will that cause it not to fire ?

Yes. Poor contact plus vibration causing a loose connection.

You got to blow harder in the breathalyzer...

1+ :roll: