Left engine only going to 2000 rpm. Any ideas?

[bprender]

Hey guys! Last weekend had a little problem with port engine. Check engine light would come on and would only go to 2000 rpm at full throttle with no real forward thrust. Same in reverse with no power. Not sure if something was stuck in intake. Throttled back at idle on right engine. Then tried to restart a couple of times than all of a sudden engine ran normal. Any ideas what might be causing this. Thanks. Brian

 

[Bruce]

How old are the spark plugs? I would start by changing them.

 

[Gym]

@bprender. The computer will limit the rpm in an overheat condition. You most likely sucked something up that blocked or reduced your cooling water intake. Look it over good while on the trailer. Get under the boat and look up into the intake grate. Also look at the water intake screen located on the left side of each jet nozzle. Did you loose pee water during the overheat?

 

[itsdgm]

X2 on what @Gym said. Anything that disrupts the flow of water in the pump (could be a piece of fishing line or a piece of wood the size of a toothpick) will cause cavitation resulting in loss of pump pressure and loss of cooling water to the engine. The engine has an overheat protection built in that limits the rpm's until it cools down. It's also possible that you have a faulty temp sensor that would trigger a false overheat condition. It would be easy to see the temp reading if you have YDS. good luck, hope you figure it out soon.

 

[bprender]

Thanks guys. Was going to replace spark plugs anyways. I was thinking something might be blocking the intake. Will give that a check.

 

[props2you]

@HELP

Any updates or resolution with this?

This has happened to me twice thus far this year. Both scenarios have been identical:

At launch, both engines start & run fine, no issues. idle, stop, start etc.

After running (stopping & starting without issue), will go to the beach, anchored in 3-4 feet of water and sit for 4-5 hours on house power running stereo etc. Upon departure, (voltage is fine for both house and start @ 12.4v) both engines start, starboard engine has no issues, starts and idles at 1200 RPM. Port engine will start and idle at 1000 RMP. Upon engaging both motors to full power (either individually or single lever) port engine maxes out at 2000 RPM. No issues with starboard.

I will turn the key off, fully power the boat down and let it sit for 10-20 seconds, power everything back up, turn on the key and start both engines and the port engine will go back to normal idle at 1200 RPM and have full power back.

It is throwing a port engine alarm and diagnostic code (which I cant see specifics, just the code #)

New plugs this season, there is no blockage and coolant is running through both engines, seems to be an electrical gremlin somewhere...

Any help or place to start would be greatly appreciated, dealer is 3 weeks out...UGH!