JimmyTilt
05-03-2012, 05:34 PM
I replaced my seized 1999 Yamaha 250 OX66 250 HP outboard on my Contender 23 Open with a similar 2000 Yamaha 250 OX66 250 HP outboard (swapped a 1999 for a 2000 model). Although the wiring harness connectors appear the same in both motors, the existing electrical rigging of the original 1999 installation is not compatible with the now-installed 2000 motor. Problems:
• When the main batteries are switched on (with ignition key off), the tilt motor actuates upward and stays on – it can’t be stopped with the throttle trim switch (it can be temporarily overridden with motor cowling trim switch up/down). However, when the ignition key is on, the trim motor is not actuated (as appropriate), but can only be tilted from the motor cowling switch as the throttle tilt switch does not actuate anything. When I turn the key off the motor trims up on its own again.
• Moving the ignition key from on to start does not provide any noticeable actions to the motor and does not power the gauges.
• There were two wires with bullet connectors leading from the splashwell rigging tube to one of the three sensors on top of the #1 cylinder head in the 1999 model; the 2000 model does not have that sensor - there is only a bolt in that location without sensor. The 1999 Yamaha shop manual does not reference this sensor that has two wires (blue and a white).
Note that the replacement motor was stand tested with a remote key and functioned properly during the decarb process. The 10-pin connector and three modular connectors (white, blue, blue connectors) appear similar in both motors. The 1999 and 2000 outboards appear identical (other than decals and the sensor described above)
I suspect that swapping two or more pins in the harness will fix the problem, but I am not sure which ones should be swapped. The 1999 Yamaha shop manual I have is obviously no help for the 2000 motor. If anyone has gone down this road before, a “lessons learned” reply would be greatly appreciated! Obviously, since I did not repower with a new 4-stroke, money is tight for me right now – taking it to a certified Yamaha mechanic is a last resort choice that I am hoping to avoid. One good post may solve this problem!
• When the main batteries are switched on (with ignition key off), the tilt motor actuates upward and stays on – it can’t be stopped with the throttle trim switch (it can be temporarily overridden with motor cowling trim switch up/down). However, when the ignition key is on, the trim motor is not actuated (as appropriate), but can only be tilted from the motor cowling switch as the throttle tilt switch does not actuate anything. When I turn the key off the motor trims up on its own again.
• Moving the ignition key from on to start does not provide any noticeable actions to the motor and does not power the gauges.
• There were two wires with bullet connectors leading from the splashwell rigging tube to one of the three sensors on top of the #1 cylinder head in the 1999 model; the 2000 model does not have that sensor - there is only a bolt in that location without sensor. The 1999 Yamaha shop manual does not reference this sensor that has two wires (blue and a white).
Note that the replacement motor was stand tested with a remote key and functioned properly during the decarb process. The 10-pin connector and three modular connectors (white, blue, blue connectors) appear similar in both motors. The 1999 and 2000 outboards appear identical (other than decals and the sensor described above)
I suspect that swapping two or more pins in the harness will fix the problem, but I am not sure which ones should be swapped. The 1999 Yamaha shop manual I have is obviously no help for the 2000 motor. If anyone has gone down this road before, a “lessons learned” reply would be greatly appreciated! Obviously, since I did not repower with a new 4-stroke, money is tight for me right now – taking it to a certified Yamaha mechanic is a last resort choice that I am hoping to avoid. One good post may solve this problem!