2008 AR210 Port engine chugging

[JAlexMN]

I've had my Yamaha out four times this year, running great each time. We went out for a 5th time and the port engine is definitely making noise. Kind of a chugging sound. I've replace the spark plugs, made sure the oil is topped off, and even switched the coils to the starboard engine to see if the noise switches to the other engine. No difference.

Its obvious that I can't get it in for service and back before the holiday weekend. Anybody have any ideas on what it might be?

 

[WREKS]

Oil must be between F and L on dipstick. If it is higher than F, it will cause problems. When you say, "topped off," what do you mean?

 

[JAlexMN]

Oil must be between F and L on dipstick. If it is higher than F, it will cause problems. When you say, "topped off," what do you mean?

It was above the L line but I added enough to just under the F line.

 

[Dfred]

Pull and inspect air filters? Or is it an exhaust back-pressure issue? Are you able to run YDIS for any trouble codes from the number of sensors that may be bad, etc?

I gather you have trouble-shot this down to engine, and ruled out drive-train (failed/binding intermediate bearings or any else)?