2005 Yamaha F250 TXR engine problem

[pursuitguy]

Hello,

Just purchased a Pursuit with a 2005 Yamaha F250 TXR (4 stroke) on the back. Had the boat surveyed, engine compression tested and did a sea trial no issues.

This past weekend I took the boat out for a spin, engine ran fine. Dropped anchor for a couple of hours but then when I went to fire it up again the engine ran rough at idle. Let it warm up for a few minutes (still ran rough) and then proceeded back to port but when I opened the throttle up further it wouldn't advance more than about 2,500 to 2,700 rpm (10 knots) regardless of the throttle setting. No alarms went off but the RPMs were fluctuating and the engine would sputter or "pop" from time to time.

I had a mechanic inspect the engine yesterday and he said there were no issues with the spark plugs or water in the fuel (as I'd originally suspected) and when he took the boat out for a trial it ran fine.

Does anyone have suggestions on what else this could be? Obviously concerned that the mechanic didn't find any issues. The engine only has 95 hours on it so had light use previously.

Thanks in advance.

 

[rodbolt]

Re: 2005 Yamaha F250 TXR engine problem

most likly clogged VST filter or injector filters or both.
why didnt the tech measure fuel rail pressure at the problem RPM and load ?

 

[pursuitguy]

Re: 2005 Yamaha F250 TXR engine problem

Problem doesn't appear to be filter or contaminated fuel at all if anyone else runs into this problem. Was a faulty sensor (water pressure) that when leaked hit the wiring harness sending faulty signals resulting in the sputtering, backfiring and inaccurate readings on the speedo (Command Link gauges). Solution - new sensors and wiring harness, apparently Yamaha has this as a recognized problem though.