Yamaha 115hp CDI or Coil Pulser????

[lachob]

hi,i have 1993 yamaha 115hp (2 stroke) with rpm problem.i only have 3000 rpm when is not in gear and 1000-1100 rpm when is on gear. after that the motor cant increase the rpm.The rpm gauge goin back to 0 ,i think thats mean somethingcut the power to the ignition coils .CDI or Coil Pulser is bad???
I was thinking that was a fuel line problem and change the fuel pump,rebuild the carbs,but looks like i have electric problem,Please help

 

[toddingalls]

Re: Yamaha 115hp CDI or Coil Pulser????

I have a similar problem with my 1990 115hp... did you get yours fixed?

 

[yamatech43]

Re: Yamaha 115hp CDI or Coil Pulser????

Need more information....first check the grounds on engine all the way to battery. Yamahas are funny about needing very good grounds. You may even try running
a new temporary ground directly from battery to block.

 

[Ballymac]

Re: Yamaha 115hp CDI or Coil Pulser????

Agreed, check all grounds. Have you checked any electrical components? Does tach stay at 0, or bounce back. First, check all grounds and make sure the timing is correct. It could be your stator, TPS or crank sensor. You can check the crank sensor & TPS with an ohm meter. Crank sensor is static, while your TPS should show ohms change throughout the full range of motion. You should also check the TPS voltage, which should show a voltage change throughout it's full range of motion (need a multimeter to test). If both are within spec, check the high speed coils in your stator. You'll need a peak voltage meter or DVA for your multimeter. Your stator has both high and low speed coils along with a lighting coil. The high speed coils take over at anywhere between 1500 & 2500 RPM. You'll need to have the boat on the water or the engine in a test tank, in forward gear, at the suspected RPM range to test. Good luck.