2004 Yamaha 200 HPDI rough idling & no power

[lemonroad]

Went to the lake yesterday my yamaha wouldnt plain out, no power. I noticed it was idling rough. Turned the key off then restarted and it ran fine for a few hrs then the same problem happened again. I turned the key off and restarted then it ran fine?

 

[lemonroad]

Re: 2004 Yamaha 200 HPDI rough idling & no power

Any help with this guys?

 

[yamatech43]

Re: 2004 Yamaha 200 HPDI rough idling & no power

Check all the grounds, that means on engine, batteries, battery switch, ignition key/dash....corrosion problem.

 

[lemonroad]

Re: 2004 Yamaha 200 HPDI rough idling & no power

I just had this motor put on my boat, it had a mercury so lots of changes. I do see a black wire under the dash that isnt connected to anything?

 

[yamatech43]

Re: 2004 Yamaha 200 HPDI rough idling & no power

Again, where most motors use a hot wire to 'complete' a circuit, Yamaha uses the ground....check all the grounds, not by looking at them or you'll be stuck like this forever....did have another thought....you might check the vacuum with a cheap vac.gauge(napa, autozone) hooked up just upstream of the ENGINE'S first fuel filter(the one in front)....this does kinda sound like a blocked vent or 'coast gaurd' valve on tank....symptoms would be it runs ok for a while then starves for gas...stop and the vacuum goes away and then runs again a little....if it happens then check the bulb right away and see if you can squeeze it, should be hard. One more thing....the rough idle....pull the O2 sensor and clean with a torch(no chemicals!!) carefully and pull the little tube that connects it to the exhaust...clean out the tube also.

 

[lemonroad]

Re: 2004 Yamaha 200 HPDI rough idling & no power

Where is the 02 sensor located? Also I tried pumping the bulb on the lake but it wouldnt pump up when I was having the problem. The vent for the tank is ran to the fuel inlet, dont see how it vents when the cap is on? Thanks for your help!!!!

 

[lemonroad]

Re: 2004 Yamaha 200 HPDI rough idling & no power

Believe I have solved the puzzle, for some reason my motor will start in gear, whenever I do that it runs rough and will not plain out. Whenever I start it in neutral it idles and runs fine. Not sure why it is starting ing gear? Thanks for you help yamatech43!!!

 

[yamatech43]

Re: 2004 Yamaha 200 HPDI rough idling & no power

Ok, sounds like the neutral interrupt switch is bad....probably starting in gear with load is causing the puter to freak out a little....never ran into this before so don't know what it would do....may have to try that one day. Congrats on finding the prob.
I said neutral interrupt switch and that's not right at all...neutral interupt lets you shift easily on lots of motors....it's the neutral SAFETY switch...(edited)