2014 starts for about 3 or 4 seconds then dies

[spin05]

So half way thru riding today my sons 14' 250f starts to die randomly. It has 32hrs on it. It restarts then dies after 3 seconds like someone hit the kill switch. Have not taken anything apart recently and he hasnt rode since last weekend when it ran great. Anybody have any ideas??? Tommorrow will take apart check every connector but after that im stumped if its not a connector.

[Thunder Bike]

Is the FI warning light on. 

[spin05]

It lights up when it starts and lights up when it dies. But only for a second or 2. My son says he thought that was normal from what he recalls.

[kawamaha]

check the vehicle-down sensor

[spin05]

 

check the vehicle-down sensor

how do ya do that or are you just talking for loose connectors and such?? not testing it

[kawamaha]

the sensor is located in front of the cylinder. remove it and shake it, it should rattle.

a correct mounted sensor (arrow up) should have 0.4 - 1.4V at the brown wire (grey is ground) when the motor is running.

at more than 3.7V it says "tilt" and will shut the engine off after a few seconds.

 

if it's not the vehicle down sensor, you should read out the error codes, must be shown in the owners manual

 

PS: wire colours are from the 450 schematics, look at the schematics in the owners manual for correct colours...

[spin05]

cool thanks. Give that a shot

[mxracermx]

cool thanks. Give that a shot

you should run a compression check. I hope it's not but that's enough hours and they have weak stock pistons. They are prone to cracking and will do just that

[spin05]

the sensor is located in front of the cylinder. remove it and shake it, it should rattle.

a correct mounted sensor (arrow up) should have 0.4 - 1.4V at the brown wire (grey is ground) when the motor is running.

at more than 3.7V it says "tilt" and will shut the engine off after a few seconds.

 

if it's not the vehicle down sensor, you should read out the error codes, must be shown in the owners manual

 

PS: wire colours are from the 450 schematics, look at the schematics in the owners manual for correct colours...

 

 

kawamaha  your the man. /it was the vehicle down sensor. I used swapatronics to verify. haha.  Now i just hope i can get the new part by friday for a 4 day race we have.  

[kawamaha]

?  good to hear!

[Thunder Bike]

Yep good to hear.

[kawamaha]

... Now i just hope i can get the new part by friday for a 4 day race we have.  

if not, you can plug a 1.5V battery or 1.2V Accu (brown + and grey -) to the connector until the new sensor arrives... ?

[spin05]

if not, you can plug a 1.5V battery or 1.2V Accu (brown + and grey -) to the connector until the new sensor arrives... ?

 

We borrowed one from a friend who is still hurt and cant ride just in case.......

[crackhead]

my mates 2012 did the same thing, vehicle down sensor

strange issue, but seems common enough with the injected 2012 kx250f's

easy fix atleast.

 

wtf cracked piston, strangest suggestion out.

[Nick Staciwa]

On 8/27/2014 at 4:13 AM, crackhead said:

my mates 2012 did the same thing, vehicle down sensor

strange issue, but seems common enough with the injected 2012 kx250f's

easy fix atleast.

 

wtf cracked piston, strangest suggestion out.

Did you order a new one or did you have a way to test if it was broken first?