• We are no longer supporting TapaTalk as a mobile app for our sites. The TapaTalk App has many issues with speed on our server as well as security holes that leave us vulnerable to attacks and spammers.

Low Idle Afr Nytro

chris_erhard

Newbie
Joined
Jan 4, 2022
Messages
5
Age
25
Location
Bozeman, Montana
Country
USA
Snowmobile
Yamaha Nytro MPI supercharged
I have a Yamaha nytro MPI supercharged with the gems controller, i am having an idle issue where AFR readings are as high as 22.4 … I have changed my low rpm Gems settings as high as possible and there is no change.

One thing that I have noticed is when I turn the key on, without starting the engine, my afr gauge boots up and displays 22.4. Is my Afr sensor going bad?

Sled runs good Afr numbers when revved up, Afr drops lower at mid rpm’s then and actually runs rich at higher rpm’s.

Sled tends to stumble off the line unless I feather the throttle.

I’m thinking it may be a vacuum leak but would the sled even run at all with Afr above 20??
Could my blow off valve be stuck closed at idle?

Thanks,
Here’s a video
 

I would guess you have a bad sensor... boosted sleds when running any kind of race gas will take out sensors.
 
Mine is doing the same thing. Replaced the sensor, same thing. Any luck?
 

Attachments

  • 20221213_201728.jpg
    20221213_201728.jpg
    92.1 KB · Views: 56
At first After start up gauge would read 22.4. Occasionally read 7.1. Replaced the wideband sensor with a bosch. Now reads 7.1 or so at start up. Give it throttle goes to 22.4. Pull the sensor out of the pipe and layed it then started the sled, same thin. Did the rag test by spraying brake cleaner on the rag and covering the sensor to read rich. Will read 7.1.
 
Only thing different is the cold air pipe for the mpi s/c. And mbrp headers and muffler.
 
I do have LEDs in ir. Replaced one of the LEDs with a different brand. Ill have to look into that when i get home. Thanks for the info.
 


Back
Top