A little history.... Have never had to work on this unit before other than normal maintenance, just over 9000 miles..(great machine) About 300 miles ago stopped having to push red button to put into reverse, it just sifts when I hit the button. (Electric Shift) About 100 miles ago the machine started to JUST Quit after it got good and warmed up (Suspect Coil) Just let it cool off for 10-15 minutes and fires right up and run again until good and warm. Discovered cooling fan has seized up (replaced) Same dying issue when warm. The other day Ran about 7 minutes down trail, stopped and idled about 1 minute. Hit throttle to leave,,, Unit Backfired and died. Would not restart, pulled home. Next day it started right up and ran good until I put it in gear. It died and wouldn't restart. 2 days later - repeat performance. Now won't start at all... Things checked.. It has spark, Fuel injector fires, fuel pump working. Valve clearance is good, Valves appear to move free when cranking. Good strong suction when I put hand over throttle body intake while cranking. Fuel injector only fires for the first couple of revolutions, then stops firing. Tried Starting fluid,, does not fire,,, double checked spark, still sparking. Any Ideas???
2008 400 TRX died
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OKAY, I got it started again using starting fluid. It idled just fine. Checked the timing as best I can and it seems to be good. It idled about 3 minutes. As soon as I touched the throttle it died. Now it will not re-start. It still has spark???? I am lost. I took the throttle body apart. It is pretty clean all except the little black electronic controlled "Jug" needle valve. It was pretty gummed up. I cleaned it up real good. I assume it is some kind of fuel control or air bypass???? I checked resistance between pins but don't know what the values should be?? In my experience it seems like it is okay but not sure. I forgot to mention that the "dying" problem when warmed up started right after I cleaned the air filter and changed the oil etc... Is it possible something got into the throttle body causing this? Or is it possible the Injector gets hot and shuts down or sticks? Not starting even with starter fluid confuses me.
Well Now,,,, Let's sort of start this thread over again,,
As I mentioned in the beginning, the fuel injector is firing but only the first couple of revolutions.... As it turns out, here is what's happening.
I can leave the key in the ON position, hit the start button, The fuel injector fires once or twice then stops firing, ALSO the spark Plug is only firing once or twice then stops firing. Once in a while, when I release the start button it sparks again as winding down.. It repeats this action every time I hit the start button.
Occasionally it will give a single spark during continuous cranking but not often. As I can not see both, the fuel injector and the spark plug at the same time, I assume they are firing on the same revolutions but neither of them continuous. It has got to be something electrical ??? CDI,,,, Sensor,,, Throttle Position Sensor maybe?? Still looking for idea's. It has not re-started sense it idled about 3 minutes this morning.. The battery is on a charger to keep it charged and it is only about 3 months old, It will crank a long time without running down so I know the battery is good.
As I mentioned in the beginning, the fuel injector is firing but only the first couple of revolutions.... As it turns out, here is what's happening.
I can leave the key in the ON position, hit the start button, The fuel injector fires once or twice then stops firing, ALSO the spark Plug is only firing once or twice then stops firing. Once in a while, when I release the start button it sparks again as winding down.. It repeats this action every time I hit the start button.
Occasionally it will give a single spark during continuous cranking but not often. As I can not see both, the fuel injector and the spark plug at the same time, I assume they are firing on the same revolutions but neither of them continuous. It has got to be something electrical ??? CDI,,,, Sensor,,, Throttle Position Sensor maybe?? Still looking for idea's. It has not re-started sense it idled about 3 minutes this morning.. The battery is on a charger to keep it charged and it is only about 3 months old, It will crank a long time without running down so I know the battery is good.
One more update---- I am done,,
I found the problem,,,, The connector under the rear right fender that connects the Stator to the wiring harness. It is milky clear, round and five wires - 3 to rectifier and 2 appear to go to EFI unit...
I was just looking everything over trying to figure out each various sensor etc. I decided to attempt a start. It fired right up. Started back through the wiring harness to make it die. Yep, made it die a few times and then it would fire right back up. Kept going until I narrowed it down... Zero'd in on the connector. I could Just touch the wires on the bottom of it and the motor would die. Flex them around and it would fire back up.
Cut the wires off the connector and hard wired them. Connector would not pull apart without destroying it. Can see black char inside it.
Problem has gone away..
Conclusion, Poor conduction through connector causing low voltage to Ignition coil and or an internal short in connector killing all voltage to EFI control killing the whole circuit... This was a puzzler!!!!
I still have no idea why it seemed to only happen when warmed up at first,,, but I am satisfied I found it.
I found the problem,,,, The connector under the rear right fender that connects the Stator to the wiring harness. It is milky clear, round and five wires - 3 to rectifier and 2 appear to go to EFI unit...
I was just looking everything over trying to figure out each various sensor etc. I decided to attempt a start. It fired right up. Started back through the wiring harness to make it die. Yep, made it die a few times and then it would fire right back up. Kept going until I narrowed it down... Zero'd in on the connector. I could Just touch the wires on the bottom of it and the motor would die. Flex them around and it would fire back up.
Cut the wires off the connector and hard wired them. Connector would not pull apart without destroying it. Can see black char inside it.
Problem has gone away..
Conclusion, Poor conduction through connector causing low voltage to Ignition coil and or an internal short in connector killing all voltage to EFI control killing the whole circuit... This was a puzzler!!!!
I still have no idea why it seemed to only happen when warmed up at first,,, but I am satisfied I found it.
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