I had an issue last week. I dropped my 2011 fe 390 on its side. Nothing hard. The tip over sensor tripped, the bike turned off. I picked up bike, started it, and off i went, for another 30 seconds anyway. The bike started to sound rough and more jolty when I gave it gas. Then it stalled as if I had hit the kill switch. I removed the spark plug cap and unscrewed the cap from wire to test for spark, I got a single spark. Long story made short I figured out that a faulty throttle position sensor was causing this effect.
A test for this spark condition is to disconnect the tps sensor. If you then get multiple sparks then your tps sensor is bad. A functioning tps should put out approx. .6 volts when the throttle is closed and up to 4.7 when the throttle is wide open.
The resistance on mine with the throttle closed was at 4.4 volts and 4.9 open throttle. I used a fine pin to stick into the yellow wire lead at the connector. With the sensor connected, start the bike. Using a voltmeter set to dc volts, i clamped the positive lead of the voltmeter to the pin and neg to ground. the blue wire(+) should read 5 volts when starting the bike. The yellow wire then tells the ecu not to start or spark because it senses that my throttle is nearly in wide open position.
A test for this spark condition is to disconnect the tps sensor. If you then get multiple sparks then your tps sensor is bad. A functioning tps should put out approx. .6 volts when the throttle is closed and up to 4.7 when the throttle is wide open.
The resistance on mine with the throttle closed was at 4.4 volts and 4.9 open throttle. I used a fine pin to stick into the yellow wire lead at the connector. With the sensor connected, start the bike. Using a voltmeter set to dc volts, i clamped the positive lead of the voltmeter to the pin and neg to ground. the blue wire(+) should read 5 volts when starting the bike. The yellow wire then tells the ecu not to start or spark because it senses that my throttle is nearly in wide open position.
