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Discussion Starter #1
Hey guys, I just picked up a 2008 KFX450R off a buddy for 900 bucks. Has a bent A-arm and a no start, the hour meter on the bike only reads 54 hrs on it and over all it isn't in all that bad of shape. I am coming off of a Honda trx700xx, it got stolen from me a couple months ago.

Now that my intro is over with, here is what I've got going on. I've got no spark and have no power going to my fuel pump. The things I have checked
Checked fuel pump fuse-good
Swapped out relay with fan relay and i have power on all wires except the white with a red tracer wire.

I had to stop for the night but am looking for ideas on what to check next, with it having neither spark or fuel i was thinking it has to be something related with each other. Any advices or help is welcomed!
 

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Check the main 30 amp fuse under the hood.

54 hours is nothing! Check eBay forever a used a arm.
 

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Discussion Starter #3
I've checked it and it is good, bike turns over fine. And good deal, hopefully once I get this issue figured out and the a-arm fixed I'll get some good use out of it!

Another thing, I've got the green light on and one red light on when cranking over.
 

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I've checked it and it is good, bike turns over fine. And good deal, hopefully once I get this issue figured out and the a-arm fixed I'll get some good use out of it!

Another thing, I've got the green light on and one red light on when cranking over.
Green light is the neutral...!

Far left is the F.I light...If it this one...check for DFI errors...see pics

ground the orange wire to the frame, turn the key on & the F.I light will blink to an error...If any...??
 

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Discussion Starter #5
Thank you, I will check that this afternoon.

What're some of the things that will kill both spark and fuel? Roll over switch? Will a kill switch?
 

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Thank you, I will check that this afternoon.

What're some of the things that will kill both spark and fuel? Roll over switch? Will a kill switch?
Yes both a kill switch & Roll over switch will cut spark & fuel...!!

Check if the roll over sensor is on it's bracket, if yes, then check it's output voltage...!!
 

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Discussion Starter #7
Jumped the hot and ground on fuel pump relay and the fuel pump runs. Pulled the roll over switch apart and the circuit board looks burnt. I am going to order a bypass for it and atleast start there. I have battery voltage at the yellow/red wire on wire, so shouldn't I have spark of am I missing something?
 

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Kms eliminator or procom ecu. Kms is cheaper
 

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Jumped the hot and ground on fuel pump relay and the fuel pump runs. Pulled the roll over switch apart and the circuit board looks burnt. I am going to order a bypass for it and atleast start there. I have battery voltage at the yellow/red wire on wire, so shouldn't I have spark of am I missing something?
If the vehicle down sensor is bad, then no, the ECU triggers the fuel injector & ignition coil on a negative pulse circuit...But the Y/R wire needed to be checked for voltage, in case of bad or dirty connection...!

here's the KMS bypass... https://www.kmsperformance.com/shop/item.aspx?itemid=9
 

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Discussion Starter #11
Okay this is the point I am at. I have checked my black/yellow grounds on ecm, and I checked source voltage on it at the white and brown in the ecm and I had battery voltage. I checked my key switch and I have power coming in and out. But I do NOT have input voltage at my roll over switch? Where else to check with that? Several manual just says to check harness and key switch. I checked continuity from ecm plug to roll over switch and had continuity.
 

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Okay this is the point I am at. I have checked my black/yellow grounds on ecm, and I checked source voltage on it at the white and brown in the ecm and I had battery voltage. I checked my key switch and I have power coming in and out. But I do NOT have input voltage at my roll over switch? Where else to check with that? Several manual just says to check harness and key switch. I checked continuity from ecm plug to roll over switch and had continuity.
Input voltage comes from the ECU at 4.75~5.25 volts...so if no voltage being sent to the roll over from the ECU, could be a bad ECU...

Check the reference voltage/input voltage of the TPS...see pic
 

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Discussion Starter #13
I pinned into the tps, I had no input voltage at it either. But when I un plugged ecm I ran a continuity test on the light blue to the ecm plug and then from the black/brown to ecm plug and I had continuity on both of them. But when I checked continuity on the black/brown, I had continuity on both the blue or the black/brown to the black/brown pin on the ecm plug. So is that telling me that those are both shorted together or what?
 

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I pinned into the tps, I had no input voltage at it either. But when I un plugged ecm I ran a continuity test on the light blue to the ecm plug and then from the black/brown to ecm plug and I had continuity on both of them. But when I checked continuity on the black/brown, I had continuity on both the blue or the black/brown to the black/brown pin on the ecm plug. So is that telling me that those are both shorted together or what?
Yes.. I suspect a short too either in a sensor or the wires...!

oh..don't stick pins into the ECU/ECM plug terminals, it can spread them causing a bad connection....!!!!

You can narrow it down by doing an self diagnostic & search for error codes...!!!

see pics..

 

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Discussion Starter #15
Tomorrow I'll unplug the plug from the tps again and do a continuity test from plug to plug to eliminate the tps being shorted internally.

And I hate having to pin into thing and back probe but without having any break out harness's it makes it tough. I used little sewing needles in hopes it wouldn't spread a plug or damage anything.

I'll get back to you tomorrow, thanks for your help. I'm hoping I can find those two wires shorted instead of having to buy a ecm.
 

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Discussion Starter #16
Okay, I eliminated the tps sensor and check the wires again and I still had continuity. So I un plugged each sensor that used the LB and brown/black and was re checking each time, when I un plugged the vehicle down sensor the short went away. So does that tell me that the vehicle down sensor is internally shorted and causing my issue?

If that's the case then I don't understand why i still didn't have any input voltage at the ecm.
 

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Okay, I eliminated the tps sensor and check the wires again and I still had continuity. So I un plugged each sensor that used the LB and brown/black and was re checking each time, when I un plugged the vehicle down sensor the short went away. So does that tell me that the vehicle down sensor is internally shorted and causing my issue?

If that's the case then I don't understand why i still didn't have any input voltage at the ecm.
Yes...the vehicle down sensor is shorted/bad and need to replaced or bypass with KMS tip over eliminator... https://www.kmsperformance.com/shop/item.aspx?itemid=9

or a Procom ECU... Procom PE E AK450 A Procom CDI Rev Box Kawasaki KFX450R 08 11 | eBay

The ECU "might" be bad also due to the vehicle down sensor shorting...????
 

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Discussion Starter #18
Well now I checked my LB wire on pin 15 out of the ecm where I should have reference voltage at but I have 12 volts coming out? This thing is running me!

What's your opinion dust? Replace ECM?
 

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Discussion Starter #20
Just an update, I got a procom ecm and it took care of the issue, bike runs pretty good. Once I figured out I had no input voltage to the roll over sensor it was a red flag, thanks for all yalls advice.


One question I do have, the bike has a two brothers exhaust on it other than that it is stock. Which number should I have the dial on?
 
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