Weird starting/running issue

[sky4]

Bike:
2012 super tenere, US market, non california. Wiring recalls both done (headlight harness and TPS/APS Sensor harness) ~89,000 miles. New battery this year, plugs done like 15k ago.


Issue:
takes 2-3 tries to start. I'll hold the starter button give it throttle etc for 20 seconds at a time. shut off kill, then key. try again eventualy seems to start. Had it also die on my while riding . Pulled over, attempted restart. on the third try it worked.

my usual start procedure is key on, kill on, push starter with no throttle input. Usual off procedure is kill switch followed by key.

Got it home to my garage. shut off kill switch, turned kill switch back on, hit starter button started instantly.

shut off KEY switch. turned key and kill back on, took 3 tries to start again.

I'm thinking the key switch might be schmooed up. it's an old bike. old key switch.

Had it cut out briefly on me yesterday as well. like less than a second. I'm not throwing any codes.

I've also had a couple instances where idle would hang at 2000 rpm, but go back to normal after shutting the bike off (kill and key) it would come back to normal.

 

[Sierra1]

. . . . I'll hold the starter button give it throttle etc for 20 seconds at a time. . . .

She doesn't like that. Starter button only, no throttle.

 

[sky4]

She doesn't like that. Starter button only, no throttle.

yeah i've definitely flooded it before/made it hard to start that way.

but my standard method is no throttle. i started jacking with the throttle a bit only when i've been pushing start for 5-10 seconds iwht no response.

 

[Sierra1]

With mine, I can't use any throttle, if I do it won't start. If it doesn't start the first time, (but. it always does) I turn the key off, then turn it back on for the start up sequence.

 

[sky4]

With mine, I can't use any throttle, if I do it won't start. If it doesn't start the first time, (but. it always does) I turn the key off, then turn it back on for the start up sequence.

when this bike is working correctly it starts best with no throttle application. i usually don't even have my hand on the grip when i start it.

what it's doing now is different. i'll run the starter for 10 seconds with zero response. i haven't gone longer than that for fear of damaging the starter. I'll typically begin messing with the key and kill switch and eventually i can get it started.

 

[mran]

Check stored codes too

 

[Don in Lodi]

Code 19 comes to mind. Several of us have had the ignition harness give off an open in the side stand switch, throwing a code 19. A strong wiggle of the harness usually clears it. Did a code show briefly on your screen? Did your throttle harness recall get taken care of?

 

[mran]

What don said. Fixxed mine directly at the key tho. Have to remove the upper tripple and drill out the security bolts. Clean and lube contacts in the key. Mine would only throw a 19 on occasion..

Can confirm with the wiring off the key or ecu. Would be good to check side stand and any other sensors inline

 

[Squibb]

That hanging the revs thing has me thinking TBs, or the balancer port cap leaking air.

Best check for codes first.

 

[sky4]

That hanging the revs thing has me thinking TBs, or the balancer port cap leaking air.

Best check for codes first.

i've seen no codes. my best theory on hanging throttle is the APS is getting old.
i'll make sure that balance cap is good though.

 

[sky4]

Check stored codes too

how do i do that?

does pulling the battery clear them forever. my negative cable is currently disconnected while i drill out security bolts/remove ignition.

 

[jrusell]

Throttle body sync would be my first step, and I would plan to have the valve clearance checked if they have not been done.
Service manual has instructions on how to access/see the trouble codes and how to clear them.

 

[sky4]

Throttle body sync would be my first step, and I would plan to have the valve clearance checked if they have not been done.
Service manual has instructions on how to access/see the trouble codes and how to clear them.

synched throttle bodies 6 months ago.

restarts hot no problem, assuming it's not up to its tricks.

i have seen nothing that would make me believe this isn't an electrical issue.

 

[sky4]

ok... so pulled my key switch, took the cover off, cleaned the contacts and lightly greased with super lube dielectric grease. seems to be working well now. ive done about 300 miles this weekend. a dozen or so start events.

switch looks to be in good shape, it was dirty, and there was some minor corrosion. it seems to be a very high quality switch. spring loaded contacts, nice thick wires. I don't think i'll be replacing it.

 

[WJBertrand]

Agree about checking valve clearances. Too tight or no clearance may prevent one or more valve from seating completely when cold. The lost compression will make it hard to start. When the engine is warm the aluminum head will expand more than the steel valve components, increasing lash clearances, potentially allowing the valves to seat better.

How old are the plugs & air filter?


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[sky4]

Agree about checking valve clearances. Too tight or no clearance may prevent one or more valve from seating completely when cold. The lost compression will make it hard to start. When the engine is warm the aluminum head will expand more than the steel valve components, increasing lash clearances, potentially allowing the valves to seat better.

How old are the plugs & air filter?


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plugs have about 18k, air filter is new.

this is decisively an electrical problem. I'll try to get a valve check in this winter though.