242 Limited - engine limited to idle

[EricF]

Greatly appreciate any input/guidance here...

2013 242 Limited. Ran well for me for period of about 12 months of regular use.

Then had to de-commission and store for about 9 months (in Caribbean). I had fogged engines, added additive to a full fuel tank, and recently replaced spark plugs prior to storage.

Upon my return, she initially started up and ran well upon re-commissioning. But cranking battery was low so had to parallel off house. (Alternator is working fine.)

Then, on one recent trip (after running engines for about 30 minutes), had trouble re-starting starboard engine. Port started and was ok. Starboard stalled a few times but then ultimately started, but couldn’t get above idle (electronic override). So I slowly idled back to port.

Both engines fine at dock and when flushing on trailer (using a borrowed cranking battery). Then I had to leave the boat (and the Caribbean) almost immediately.

I will be returning soon and am hoping to develop a key diagnostics list ahead of time (as I will need to source any parts before then from the US):

• Replace both batteries.
• Bad fuel?
• Fuel filters?
• Air filters?
• Oil? (Perhaps over filled.)

What else could limit engine to idle speed?

Thanks a lot!

 

[Cobra Jet Steering LLC]

Faulty heat sensor , or engine is actually overheating from clogged cooling line from pump, or low oil level.

 

[EricF]

Many thanks.
Will replace both batteries and change oil and filters first, and hope that fixes the problem. Can the cooling line be inspected easily?

 

[zipper]

During those 12 months of use and the decommissoning, were the engines flushed with salt-away or similar. I agree with @Cobra Jet Steering LLC on his diagnosis of a faulty sensor or overheating (limp mode) due to clogged cooling passages or stuck thermostat.

 

[EricF]

Thanks zipper. Flushed after every use and extensively before de-commissioning but not with salt away (my mistake). Cooling water did seem to be flowing ok though before and during shut down idle.
Had various issues with intermittent ‘check engine’ warnings in the past but without any obvious effects on performance or functionality. Getting any sensors repaired here in Caribbean may be a serious challenge.

 

[ZGhost]

When was the last time you replaced the spark plugs? Batteries need to be maintained while decommissioned. I would replace both batteries and plugs. Make sure the new batteries are maintained when not in use. Report back pls.

 

[Drexx3]

The third sentence in the original post says "Then had to de-commission and store for about 9 months (in Caribbean). I had fogged engines, added additive to a full fuel tank, and recently replaced spark plugs prior to storage. "

 

[EricF]

Replaced both batteries, all plugs and both oil filters, and changed oil. Flushed engines for extended period prior to launch. Boat ran very well without any problems. (Although actual root cause of previous ‘forced idle’ problem uncertain.) Thanks for your input guys.

 

[Compatico]

, and recently replaced spark plugs prior to storage. "

^This.
You change plugs AFTER storage to put in new CLEAN plugs. If you don't replace after fogging, you risk having the plugs not reach proper temp and mis-fire. If you don't replace after fogging, then it's a good idea to remove and clean them before first use.