Engine shuts off randomly

[Ruggybuggy]

This must be contagious. Riding to work today and sled just stalled while idling for no reason. Started up right away and sounded like it was running on one cylinder but cleared itself after about 10 seconds.

That was a sign to skip work and go sledding.......... Ruggy did you get your low end bog fixed?

Put back in the Pink spring and all is better. I actually held the brake and throttled it up to make sure and no bog but did smell a little burning rubber.

 

[Ruggybuggy]

When my son comes home from school, we'll be rippin' into it again. Since I have an almost whole wiring harness, I'll replace the complete wire for the speed sensor to eliminate that.

Good luck and keep your eyes open for any bad wires that may be touching to ground. I had a quad once that did the same thing and it turned out to be a rubbed though wire at the steering post, would ground the kill switch.

 

[Mooseman]

We did some quick testing and the engine would die if I poked around wires on the left side on the big connector with 8 wires but not consistently. The lights would start to flicker and the engine stuttered and would eventually die and only if the engine has been running a good while and hot. Will have to look further into it tomorrow as we had to leave for dinner.

Next will be to remove the airbox but remove the vacuum sensors from it so I can leave them connected and have the engine running so I can poke even further. We have a bit of time as it will start raining tomorrow for a couple of days.

 

[canoehead]

Chasing wires is not fun. Good Luck sounds like you have a place to start. Are you looking at the front of the sled when you say left side or sitting on it?

 

[Mooseman]

Always from the sitting position

 

[Mooseman]

SOLVED

I think we found the culprit. This ground wire from the battery was disconnected. It wasn't readily apparent as it was partially pulled but still within the connector. Tested by unplugging it while it was running and the headlights started flickering and the engine would eventually die. Also,that wire was frayed at the battery terminal so I soldered a new separate terminal for it.

I also checked the yellow ground block which is apparently troublesome by melting and it is fine.

 

[yamahas]

Nice find! Thanks for following up.

 

[Ruggybuggy]

Perfect and one with the updated ECM from Porkchop's sled your all set.