bad speed sensor ?

[w8tn4snow]

w8tn4snow
i had the exact same problem as you. if you want to run the sled you MUST diconnect the speed sensor. just follow the wiring from the sensor and youll find the plug in close to the tank area. unplug and ride. it will give you codes but you can ride without issue. your sled will suddenly stall if you leave it plugged.

Yeah thanks for the heads up , this post was last feb though , a new bearing and sensor and it was good to go . If id had known i could unplug it on the trail and keep going it would have saved the day though .

 

[GT Mills]

Edited Jan 7, 2025:

We aircraft builders use Yamaha Genesis RX1, Apex, Phazer, Nytro and Vector engines for aircraft because they are [bleep]-ing awesome. In the past I (Mohawk Aero) always just used the stock MFD/tach. Later customers (post 2017) started to not use it. Some guys testing the Apex on an engine stand before using them to fly with reported sudden engine-outs for no apparent reason, after hours of running fine. This is not good when you're flying, folks. On a sled no big deal, but for us it could cost the aircraft or a life. When they restarted the engine they fired right back up and kept on running. I suspect they had the wiring screwed up after eliminating the speedo sensors.

The speedo sensor: This is a three-wire sensor, I read that it was a redundant design so in case one side iced or discoed the other might still work. I no longer think so. What I now believe is that sensor positive is blue wire, sensor ground is Black/Blue, and SIGNAL OUT, back to ECU, is the White wire.

(This paragraph is basically unedited) To trick the ECU into thinking the machine is moving, with the sensor unplugged, what do sledders do? Loop [positive Blue wire] feed to ground? Or is a resistor needed? I KNOW (because I have purchased several dozen motors and can tell which ones have honest miles and which ones are liars) there are guys out there who disco-ed the sensors to defeat the odometer, so how are they keeping the ECU from thinking the machine is not moving and forcing it to go into limp mode? Thanks for your time and help.

 

[thor452]

I don't think anyone has done this to trick the odometer as Yamaha owners don't care much about miles on the 4 strokes. when the sensor gets chewed by a bad bearing you can disconnect the gauge pod and it will run just fine. I think what you would benefit from is talking to the guys that put the apex engine in ORV'S. Like Polaris razor apex conversion there are allot of them out there.

 

[GT Mills]

Hey thx! A quick search and I found three or four sources for Apex ORV conversions.

 

[thor452]

 

[GT Mills]

Not sure yet, but I think all these guys are using the speed sensor.