Intermittent loss of rpm starboard engine

[TheGreekTitan]

Hey guys,

So, first trip out this season, and by God it was awesome!

Been about 8 - 9 months since the last venture. Did not put Stabil in the fuel tank, nor did I change the oil....I know, bad boat owner.

As the title states the starboard engine would lose about 2k rpm while running at 1/2 -3/4 throttle. Port engine felt rock solid. Ran it for a while at speed and in no wake, then anchored in a cove. No issues in no wake btw. Did not have any problems on the trip back to the marina. Ran full throttle for a while, and damn that was fun!

Really didn't run her long. We had guests, and I'm the only one who knew there was an issue.

Any ideas as to what the problem may be? First thought was old gas, which was half a tank and I filled her up before we left the marina. So full tank, half old, half fresh.

Thanks in advance for any input!

 

[zipper]

You have a bad Spark plug or a plug boot is not tight. How old are they?

 

[BeauSko]

What year/model is the boat?

Was the boat winterized before this last outing?

How does the oil level and spark plugs look?

Anything in the clean out ports?

I would start with checking the clean out ports, intake, impellers, and nozzles...the smallest piece of debris can cause this. Then take a look at the oil and spark plugs. Can always take a look and make sure the bucket is going thru the entire range of motion. U can do this while on the trailer by just comparing it to the port engine (may not be opening all the way). If it doesn’t take a look at the throttle linkage.

If it was bad gas, I think your port engine would be doing the same thing. Few things to get ya started. Good luck!

 

[WilCo]

I wasn't losing 2-3k rpm, but there were a lot of good suggestions offered when I posted something similar recently.

https://jetboaters.net/threads/engine-missing.26657/

Final outcome was dielectric grease on all the electrical fittings and removing a bit of oil are my most likely solutions, but give the thread a read and see if anything else jumps out at you.

 

[TheGreekTitan]

Thanks all!

2015 SX210. Very low hours

Clean outs were clear.

Spark plugs make sense. Oil level was good, but should be changed. I keep the boat in dry stack on the lake. Every end of season I have them put her on a cleaning rack, and i clean and winterize myself. I did not get a chance to do that last year, and did not want to pay the ridiculous price the marina charges.

Thanks again, I'll read the suggested post, and check on all your suggestions this week.

 

[Scottintexas]

If the problem went away on the return trip i would chalk it up to old fuel

Add a bottle of seafoam and go have another day with it to see if the issue shows again

 

[tdonoughue]

(and change the oil and plugs)