Engine anomaly and voltage drop

[Ras210]

Hi all
I am new to jet boats but have a question. I purchased a 2010 Seadoo challenger 430hp twin engine boat. This past weekend shortly after start up - as I accelerated the warning beep sounded, check engine light lit up and engine idled roughly / as well volt gauge dropped well below 10 and flickered in that range for 2-3 minutes. Boat was in limp mode. I turned it off restarted engines and it went away. It did this twice. Any ideas what I should look at? Could it be the voltage regulator? In-line fuse? Any thoughts on possible solutions? Thanks in advance for help.

 

[Luc Lafreniere]

I'd start by checking your spark plugs.

 

[Ras210]

A bad plug shouldn’t drop voltage down to where engine goes into limp mode would it?

 

[Julian]

I would check all your battery cable connections first.

 

[Luc Lafreniere]

It's the fact that your engine idled roughly and failed when you accelerated. Bad plugs can definitely cause those symptoms. I'm not familiar with the electrical on your boat. But as Julian just pointed out, that is an easy thing to do first and foremost.

 

[Ras210]

Will check out all connections then fuses then plugs. Are plugs difficult to get out? Do I need and special lube to replace to put them back in?

 

[Luc Lafreniere]

You just need the proper spark plug socket with an extension. No lube necessary. Just don't over tighten when you put them back in. There are torque ratings, but generally, you hand tighten (loosely) until it stops turning, then do 1/4 turn further with your ratchet. The only thing you may want to apply is some dielectric grease on the coils (where they contact your engine) when you put them back in to avoid any water from somehow getting in there.

 

[David Martin]

How old are the Battery's...........I purchased a 2013 SX240 (with 23 hours) on the clock, I had a few low voltage alarm and general weirdness with alarms on start up......New Battery's solved the problem. These boats have so many electronic systems any battery/voltage drops ect....can upset all the computer controls for sure.

 

[Ras210]

Battery is 6 months old.
I checked batt connections and starter g do uses all seem good - will pull plugs to see. What am I looking for in terms of a bad plug? Discolouration/fouled plugs? How would I distinguish a bad plug from a good one? I plan to replace the 30a charger fuses just in case and maybe I just replace all plugs so I start from a clean slate?

 

[Luc Lafreniere]

Bad plugs, first section: Fouled Spark Plugs

I'd also compare the gap of a new to an old plug.

But yes. You can also compare to a new plug if you have one. Personally, I'd just replace them with new ones since it's so cheap. If it solves your problem, get rid of the old ones. If it doesn't, then keep the old ones as spares and continue diagnosing.

 

[Ras210]

Thank you will start with set of new plugs hoping this solves it