2003 Yamaha 150 OX66 Not Shutting Off

[cford28]

I have a 2003 150 OX66. Starts and runs fine. I tried to turn the engine off and it will not turn off. Pulled the rip cord and it still will not turn off. When I turn the key to the off position (with engine running still) the gauges and other electrical components controlled by the ignition switch turn off. This tells me that the switch is most likely fine. I have been reading a lot of different posts and still do not have a clue what is wrong. The problem started two days ago, when the temp got into the mid 20's overnight. That afternoon, the temp was warmer and the engine turned on and off normally. The next morning, the same thing, it would not turn off. Any ideas? I had to pull the plug wires to turn it off.

 

[99yam40]

Re: 2003 Yamaha 150 OX66 Not Shutting Off

the key and kill switch both ground the (I believe)white wire to keep spark from reaching the plug coils.

I think you have a problem with the ground wire or the white wire not making good contact somewhere

 

[cford28]

Re: 2003 Yamaha 150 OX66 Not Shutting Off

Anyone else have any suggestions?

 

[boscoe99]

Re: 2003 Yamaha 150 OX66 Not Shutting Off

As noted, the white wire to the motor is grounded to stop the motor from running. Either the key switch or the kill switch will apply the ground.

Verify that the white wire has continuity to the CDI on the motor. Then, verify it is grounded. If the motor will not stop running then the CDI is defective and must be replaced.

 

[cford28]

Re: 2003 Yamaha 150 OX66 Not Shutting Off

Where does the white wire ground? Is it common for a cdi to be defective?

 

[boscoe99]

Re: 2003 Yamaha 150 OX66 Not Shutting Off

The white wire is connected to a ground source at one end and to the CDI at the other end. In between are the key switch and the kill switches. If either switch is closed then a ground is applied to the CDI. The motor will then stop running.