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Discussion Starter #1
So after reading some of these forums I’m prob gonna be spending some money on new things because I’m pretty sure I fried something

Any way bought this rolled bike , was sitting for 4 year before I bought it so I drained gas tank and put fresh in and hooked battery charger up to it ( bad idea to many amps I know this now) any way it ran like a boss when it started so I know it runs amazing ! But now won’t start , pump is on but no spark to coil pack , bought used one off buddy that for sure worked but still nothin ,all fuses are good but one of the 10 amp fuses were blown( fixed now ) but now where to I go ? The roll over Sensor? Ecu? Doesn’t seem to be any shorted wires but didn’t fully go in to harness , ive checked wires with a light tester and all have power help !
 

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So after reading some of these forums I’m prob gonna be spending some money on new things because I’m pretty sure I fried something

Any way bought this rolled bike , was sitting for 4 year before I bought it so I drained gas tank and put fresh in and hooked battery charger up to it ( bad idea to many amps I know this now) any way it ran like a boss when it started so I know it runs amazing ! But now won’t start , pump is on but no spark to coil pack , bought used one off buddy that for sure worked but still nothin ,all fuses are good but one of the 10 amp fuses were blown( fixed now ) but now where to I go ? The roll over Sensor? Ecu? Doesn’t seem to be any shorted wires but didn’t fully go in to harness , ive checked wires with a light tester and all have power help !
Welcome to the Forum.....!!!!

Is your ECU OEM factory...???

Does the (far left) F.I dash light remain ON or flashing while trying to start...!!!

The battery needs to be fully charged 12.8v standard or the DFI & sensor don't function below 12v...!!

Do you have access to a Digital multimeter which you'll need to proceed to trouble shoot...?? If not Harbor freight sell them for $6.36 see picture below .

Motor completely stock..or has upgrades...list them if any...cams, intake exhaust fuel controller ect...??

When it was running, ran it for a short time, turned it off & wouldn't start or did anything happen while riding it causing it to not run, crashed, rolled or flipped it...???

If it sat for 4 years with fuel in it...check the fuel flow rate by removing the hose, turn the key ON, see if it pumps fuel...see pic

you'll need to test the output voltage of the vehicle down /tip-over sensor...see pic
 

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Discussion Starter #3
No light on just neutral light and reverse light , all bone stock
Previous owner flipped it but got it running three different times , once after changing gas , buddy came over didn’t believe me and started up and started 10 mins after that to see if the battery charged , bike ran perfect all three times prob about 20 mins running each time but now won’t start , fuel pump on and injector sprays gas but no spark to coil where do I begin
 

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So check voltage on roll over sensor ?
Yes...check the tip-over's output voltage & check if the fuel flow rate when the key is turn on...

Also check for 12v on the ignition coils Y/R wire to frame ground...If not..
check the handlebar start/stop/starter button/head light switch for 12v on the brown wire to frame ground & follow the wires to where they plug into the main wiring harness "Check that connection" for being loose, dirty or corroded...!!!.


wiring schematic (color coded)...see pic
 

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Discussion Starter #6
Checked fuel good , checked y/r wire to ground got 12 v outta that and brown ground got 12v there can’t figure out how to get 12v from roll over sensor when forum says to keep it hooked up ,
 

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Bought a new regulator, and rollover sensor , new battery and new coil , new fuel pump relay as well still no spark to plug and fuel pump still won’t turn on
 

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Bought a new regulator, and rollover sensor , new battery and new coil , new fuel pump relay as well still no spark to plug and fuel pump still won’t turn on
Ok! Save your money & don't buy anything else until the problem is found...

I'm suspecting either a bad ECU or a faulty vehicle down sensor...I attached the fuel pump/injector circuit diagram below...!

The vehicle down sensor will cut the fuel & spark when activated by rolling the quad...so you'll need to test it before anything else.!!!!!!!

Yes you have to keep it hooked up...!... but stick the meter leads into the back of the electrical connector of the Vehicle down sensor to test it...or stick pins into the wire to make contact to measure the voltage...if you can...!!

If the vehicle down sensor checks out good..I think you might need to replace the ECU or do you know of someone with a KFX450 near you to borrow an ECU from to see if your will start...????
 

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Discussion Starter #9
Okay so now it has fuel and spark but the black wire with red line that goes to Ecu and it’s not grounding it but if u take a piece of wire from relay to ground I have pump and spark , but it still won’t run , betting my money on ecu for sure now
 

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Okay so now it has fuel and spark but the black wire with red line that goes to Ecu and it’s not grounding it but if u take a piece of wire from relay to ground I have pump and spark , but it still won’t run , betting my money on ecu for sure now
Yea! It's pointing to the ECU...It won't run because the ignition Coil & injector activate by negative pulse
 

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So do you think it’s save to drop the money on a ecu ? And the reasoning why I need a ecu is because I hooked car charger up to it ? Pretty much fried it ? Good assumption atleast ? Thanks dust devil
 

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So do you think it’s save to drop the money on a ecu ? And the reasoning why I need a ecu is because I hooked car charger up to it ? Pretty much fried it ? Good assumption atleast ? Thanks dust devil
Before spending $400.00 new or less used on a ECU
I'd first recommend that you double check the output voltage of the vehicle down sensor..!!

You can stick the meter red & black leads into the back of the vehicle down sensor connector with it hooked up...

red meter lead into the Y/G sensor wire..
Black meter lead into the Brown/black sensor wire...

with the arrow on the down sensor pointing up should read be between 3.7~4.4 v DC

Post exactly what the voltage is...!!!
 

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