Random engine stoppage/stall

[norcalwelder]

I wasn't really able to find what I was looking for using a search, so maybe somebody can clue me in on what is happening, or what to search for. Anyway, last night I fired the bike up and let out the clutch to take off. At about 15mph the engine just kinda ran out of RPM like it had ran out of gas. The check engine light came on as well. I put the kick stand down, turned the ignition off and back on, and the bike started and ran just fine. Today, I was doing some slow speed handling in a parking lot and put the clutch while in first and got something almost the same, except no check engine light. (Really bright sun outside, so I might just have missed it) I hit the starter and it fired right up like nothing had happened. My kill switch was disconnected by a shop because it was causing some random stalls and such several years ago. Any ideas?

Edit--TPS range is from 16 at idle to 100, just like it should be. Idle is set at 1250-1350.

 

[VEGASRIDER]

How many miles on the bike?

 

[ChevyFazer]

it sounds like intermitent power loss, it could be the kill switch again or could be as simple as one of the battery cables coming loose. the battery thing happend to me when i first got my bike and had the same exact symptoms.

 

[Motogiro]

Check where the shop made a jumper to bypass the kill switch.
Other than that you could have failure in a number of areas. Fuel pump, pinched fuel line, bad fuel. Loose electrical connectors including battery terminals. Check your side stand switch If there's an intermittent problem with it it can kill your engine if the bike is in gear.

 

[norcalwelder]

50,000 miles on the clock, and the battery might be a possibility as I wired in a 12v plug before my last long trip. I didn't notice the headlights going out or anything the first time (it was dark).

 

[ChevyFazer]

when mine did it it was the neg side that had worked itself loose and the bike would lose power to the engine but nothing else unless i went WOT then it would run fine (stator output increased?) but only one or 2 times did everything shut off and that was a day or 2 before i found the probelm and the the bolt had worked itself completly out and would touch the terminal every now and again

 

[Motogiro]

50,000 miles on the clock, and the battery might be a possibility as I wired in a 12v plug before my last long trip. I didn't notice the headlights going out or anything the first time (it was dark).

If your tank was up, also check your fuel and vent lines didn't get kinked..

 

[norcalwelder]

Hasn't happened since, and the only thing wrong that I've found was that apparently my cousin (the previous owner) stuck the coolant reservoir overflow tube INTO the left gas tank vent line! When I figured out that that wasn't normal, I pulled the hoses apart and had decent amount of coolant run out. Hopefully it wasn't actively putting coolant in the tank! I was trying to figure out why my coolant reservoir overflowed in the parking lot and that was why.... I'm thinking maybe I got some sketchy gas because right before this happened those two times, I filled up at kind of a sketchy gas station.

 

[TownsendsFJR1300]

+1 on checking the kill switch bypass and the battery connections...

Please post what you come up with...

 

[TownsendsFJR1300]

Hasn't happened since, and the only thing wrong that I've found was that apparently my cousin (the previous owner) stuck the coolant reservoir overflow tube INTO the left gas tank vent line! When I figured out that that wasn't normal, I pulled the hoses apart and had decent amount of coolant run out. Hopefully it wasn't actively putting coolant in the tank! I was trying to figure out why my coolant reservoir overflowed in the parking lot and that was why.... I'm thinking maybe I got some sketchy gas because right before this happened those two times, I filled up at kind of a sketchy gas station.

Unless the coolant tank was way overfilled with coolant, I believe the fuel pressure/fumes would expand TO the coolant tank , not the other way around...

5+ gallons of fuel in a hot gas tank, vibrating as your riding, in sun is going to make a bit of pressure...