Bike Runs Intermittently! Help!

[tgroah]

This is a really weird situation I've found myself in. My bike will sometimes start right up and run forever. Then I can shut it off, and it will not start back. It's as if fuel or spark has been cut. The bike will also exhibit the same behavior cold. The tach goes through it's normal functions, and I hear the pump prime (even when it won't start).

I've made sure I have a great battery charge. I have checked for proper connections, and I have checked fuses.

Any ideas as to what could be the culprit?

Thanks for any ideas you guys may be able to lend.

 

[Motogiro]

This is a really weird situation I've found myself in. My bike will sometimes start right up and run forever. Then I can shut it off, and it will not start back. It's as if fuel or spark has been cut. The bike will also exhibit the same behavior cold. The tach goes through it's normal functions, and I hear the pump prime (even when it won't start).

I've made sure I have a great battery charge. I have checked for proper connections, and I have checked fuses.

Any ideas as to what could be the culprit?

Thanks for any ideas you guys may be able to lend.

From what you're describing it sounds like the kick stand safety switch. Does the starter turn the motor and it doesn't fire up or is it dead, no starter noise? Check wiring and plug at side stand safety switch.
Once it's started does it ever die on you? That could be the, "Kill Switch"

 

[tgroah]

It rolls over and over. Just doesn't catch to fire.

 

[Motogiro]

Do you have spark? Is there a raw gas smell from the exhaust when you crank it?

 

[tgroah]

I'm going to check that now. It only smells like raw gas after i keep cranking on it

 

[deeptekkie]

In the old days when coils were filled with oil, or all bikes had carbs, (as such), either would have exhibited this exact behavior, (it would have definitely been bad coils or vapor lock). On these fine machines though I think Cliff is on the right track. Since you are getting gas it must one of the safety interlocks somewhere. Just my biased, un- professional opinion. Good luck!

 

[Motogiro]

Fouled plugs??? Are you getting spark?
I'm wondering if you got some bad fuel or contaminant in the fuel. Check to see if you have spark...

 

[tgroah]

Fooled with it some more last night. It now starts and runs for roughly three seconds then stops. I can do this over andover until i kill the battery.

There is a small black enclosure with " UP" embossed on the side. Sounds like something slides inside of it. I wiggled it when it would not start and it started run briefly.

Any idea what this is? This might be sheer coincidence too.

 

[TownsendsFJR1300]

Fooled with it some more last night. It now starts and runs for roughly three seconds then stops. I can do this over andover until i kill the battery.

There is a small black enclosure with " UP" embossed on the side. Sounds like something slides inside of it. I wiggled it when it would not start and it started run briefly.

Any idea what this is? This might be sheer coincidence too.

Sounds like the "lean angle sensor". Its designed to turn off the bike if the bike tilts too far/falls over when running. Its usually under the left side pod (at least on my 2007)


EAS28130
CHECKING THE LEAN ANGLE SENSOR
1. Remove:
• Lean angle sensor
(from the bracket.)
2. Check:
• Lean angle sensor output voltage
Out of specification → Replace

a. Connect the lean angle sensor coupler to
the wireharness.

b. Connect the pocket tester (DC 20 V) to the
lean angle sensor coupler as shown

c. When turn the lean angle sensor to 65°.

d. Measure the lean angle sensor out put voltage

Lean angle sensor output voltage
65°: 1.0–4.0 V

 

[Motogiro]

Fooled with it some more last night. It now starts and runs for roughly three seconds then stops. I can do this over andover until i kill the battery.

There is a small black enclosure with " UP" embossed on the side. Sounds like something slides inside of it. I wiggled it when it would not start and it started run briefly.

Any idea what this is? This might be sheer coincidence too.

That lean angle sensor has three wires. It looks like wire Y/G is the common wire and B/L and Y/G are the triggers. If the bike tilts to much in either direction and you get contact it send a signal the tells the CPU to stop engine. See if you can unplug this assembly and start the engine. I'm including a PDF with the schematic. The lean angle/tilt sensor is # 16 in the circuit.

Also can you keep it running with throttle open? Or is the Idle the problem?

 

[Motogiro]

Sounds like the "lean angle sensor". Its designed to turn off the bike if the bike tilts too far/falls over when running. Its usually under the left side pod (at least on my 2007)


EAS28130
CHECKING THE LEAN ANGLE SENSOR
1. Remove:
• Lean angle sensor
(from the bracket.)
2. Check:
• Lean angle sensor output voltage
Out of specification → Replace

a. Connect the lean angle sensor coupler to
the wireharness.

b. Connect the pocket tester (DC 20 V) to the
lean angle sensor coupler as shown

c. When turn the lean angle sensor to 65°.

d. Measure the lean angle sensor out put voltage

Lean angle sensor output voltage
65°: 1.0–4.0 V

We need a picture for instruction (b.)

 

[tgroah]

I can't keep it running with the throttle. It behaves as though you've just flipped the kill switch.

 

[Motogiro]

I can't keep it running with the throttle. It behaves as though you've just flipped the kill switch.

Pull the spade connectors off the kill switch and make a jumper between the spade connectors. We had a member with a bad kill switch and this confirmed it. Make a jumper and tape it up so it can't get grounded.

 

[necrotimus]

Pull the spade connectors off the kill switch and make a jumper between the spade connectors. We had a member with a bad kill switch and this confirmed it. Make a jumper and tape it up so it can't get grounded.

If you don't want to pull off the connectors you can also strip the wires a bit and run the jumper there. That is what I did. Just make sure whatever option you choose you tape it well. I will be installing my new kill switch as soon as I have a free weekend.

 

[tgroah]

I'll do that when I get home this evening. I tried similar jumpers on the kick-stand switch, and the clutch safety switch. I also left them unhooked and tried as well.

 

[TownsendsFJR1300]

We need a picture for instruction (b.)

I was copying and pasting from my on computer PDF shop manual, the picture wouldn't copy..

If he, or anyone else, wants a PDF copy for an 07, e-mail me direct (my member name @AOL.com) ..

 

[tgroah]

Is there a way to bypass the lean switch?

 

[Motogiro]

You might unplug the tilt switch and see if it starts. Don't know the actual configuration of the lean angle switch. I don't think the schematic is showing it accurately. Could be a Normally Open or Normally closed loop. Just off the top of my head I would guess normally open so I would try unplugging it first.

Also, We just re-installed a spark plug (for a forum member) that had worked it's way out of the head and the bike would not start. We got one ignition of all cylinders and then it puffed out. It would not restart. We reset the ECU by disconnecting the battery for a few minutes and then tried starting it. Still didn't start but then I opened the throttle while cranking and it started and stayed running. Sometimes the ECU will learn a bad habit from some type of anomaly and when the anomaly is gone the ECU still treats the engine the same way hence it will run funny or quit. Try the disconnect battery routine. It may work. Open the throttle when you try to re-start.

 

[tgroah]

Well i'm fairly certain of the problem now. I made my bike into a streetfighter. By doing so, i had to relocate the lean sensor. I oriented the long axis of the sensor up and down. It should be horizontal correct? Can someone confirm this?

 

[Motogiro]

Well i'm fairly certain of the problem now. I made my bike into a streetfighter. By doing so, i had to relocate the lean sensor. I oriented the long axis of the sensor up and down. It should be horizontal correct? Can someone confirm this?

It is a lean angle sensor so I would say yes it should be oriented the same way as it was. Unless you're going to by pass it but I personally don't recommend it.

Perhaps one of our own naked modifiers on the forum can help with how/where to locate the sensor.
So I'll assume it started now?