>>HEAD COUNT<< No idle/stall and high idle dilemma..

[cpg]

2012 with 15k miles.
High Idle up to 3800 and no idle.
Runs great when it is not acting up.

It will start and run if throttle is applied.
If throttle is let off it dies during the no idle issue.
It jumps back and forth from hi to low with the high idle happening more often.

No fix for the high idle. some times key off and on fixes it some times just need to ride it and it goes away until it comes back.

 

[Ramseybella]

2012 with 15k miles.
High Idle up to 3800 and no idle.
Runs great when it is not acting up.

It will start and run if throttle is applied.
If throttle is let off it dies during the no idle issue.
It jumps back and forth from hi to low with the high idle happening more often.

No fix for the high idle. some times key off and on fixes it some times just need to ride it and it goes away until it comes back.

The Fix is as i have been saying wiring harness has fixed this 98%, get on the horn YAMAHA USA Customer service and get a decent service manager to listen to your blues...
KEEP BEATING THE DRUM and DON'T STOP... Someone will get sick of you and listen.
It's not just a fluke or freak one off happening, the 12 and 13 have had this issue more than the 10 and 11.
I was told directly from the tech that replaced my harness, he also told me they can't find the gremlin in the harnesses they replaced but they now realize it's what fixes the problem.

 

[cpg]

Thank you!
I am trying.

 

[jjc1957]

My 2015 non es stalls maybe once every tank at the worse possible time. I just got back from a 1,250 mile trip in the 90 degree heat and it stalled a few times. I was with three harley riders and will never live that down. Seems to like stalling as soon as I pull the clutch in at slow speed. The bike never idled smooth 900 RPM to 1,100 RPM. I think I will try the reflash this winter. Seems to run like my Moto Guzzi maybe a bit better.

 

[Riley8]

I had similar stalling problems with my 2017 CA model ST. Adjusted R. TB to 3/4 out and did TB sync=helped a little but not much. Read forum online review of Booster Plug made in Denmark. I order one and this fixed problem along with smoothing out throttle response and reducing jerky throttle response. I highly recommend ST riders with similar symptoms to try the Booster Plug.

 

[jjc1957]

How hard was it to install? I found a website selling them for $159.00 plus shipping. Reflash is $200 plus shipping but you need to remove the ECU

 

[Riley8]

It is very easy to install. You will need to remove the bolts holding the front of the fuel tank down and lift the tank. One of the Booster Plug leads plugs into the Air Intake Temperature sensor in the side of the air box. The other lead connects to the lead that plugged into the airbox. The position you install the temperature sensor is optional but I mounted mine between the fork leg and the frame on the right side. Reinstall the fuel tank securing bolts and you are good to go. FYI: Booster Plug comes with install directions and they have a money back guarantee. I have not ridden a ST with a re-flash by a competent technician so I can't compare but I do like the ability to quickly put my machine back to stock and be emission legal for resale purposes (though any new owner after riding it both ways wouldn't want to remove it).

 

[EdR]

I will throw my ST into this list. 2013 with approximately 12200 miles on it. Had first stall mid-August, thought nothing of it. Then this past Thursday (Sept 20, 2018) experienced the high revving when not touching the throttle. Once that got sorted (via turning off letting sit and back on a number of times) it began to have the stall issue the rest of the day (but not high revving), this was a cooler morning, and having read some on this forum it seems cooler temps are not helpful...which is very frustrating as this is an adventure bike! Also I just bought it at the start of August. Have had it what? 6-7 weeks. I must have missed this issue in my research. Anyway, when running properly its a champ.