09 212x starboard mr1 rough idle then die, then all good?

[RXBoost]

We've been to the lake a handful of times this year and each time something bad has happened.

This time we were unloading the boat from the trailer and I was starting the engines. Got them both started and as I was backing it off the trailer the starboard engine died. Turned it back on, idled for a few seconds then died. Turned it back on, put it in neutral and ran it at 6k rpm for about 3 seconds. After that no problems at all except the idle has a little flutter to it compared to port side. No lights no nothing. It ran fine for the couple hours we were at the lake and never died again.

Would the first place to start be the plugs? Hate to say it but I've had the boat 4 years and haven't ever changed them.

For those wondering, the other times we've been out:
1st - I forgot to secure the seat cushion after unplugging the charger from my wall so at 60mph while towing it flew out so had to repair it.
2nd - I adjusted the throttle on the perfect pass and didn't completely latch the engine cover. It opened while towing at 60mph. Slightly bent the hinges but it's fine.
3rd - the driver side brake locked up while driving home. Only noticed it because I saw smoke and smelled something burning once I got home. It felt like my truck (19 ram cummins) was working hard to pull the boat that day and now I know why.
4th - this engine thing

 

[zipper]

I would change the plugs first. Mr-1's like fresh spark plugs. It might help to make a pre launch checklist. Stuck calipers happen, I had one freeze up, hard to feel behind my 3/4 ton duramax. So much heat in the bearing, it thru a bearing buddy bra and slung grease all over the rim. Had to replace the caliper and the bearing buddy.

 

[RXBoost]

I would change the plugs first. Mr-1's like fresh spark plugs. It might help to make a pre launch checklist. Stuck calipers happen, I had one freeze up, hard to feel behind my 3/4 ton duramax. So much heat in the bearing, it thru a bearing buddy bra and slung grease all over the rim. Had to replace the caliper and the bearing buddy.

I will pick up some spark plugs and see if it makes a difference. Now that I am looking up these part numbers I seem to remember changing these out, but its been a couple years. I've been a boat owner since 2009 and never had this weird string of things happen. I guess my brain is not functioning as well the older I get

 

[zipper]

The plugs are the CR9EB right? Or is it the 3521? Now that I am looking up these part numbers I seem to remember changing these out, but its been a couple years. I've been a boat owner since 2009 and never had this weird string of things happen. I guess my brain is not functioning as well the older I get

The Mr-1’s in my 07 called for CR9EB. I believe the engine data tags on the engine hatch and under the air cleaner give plug type and gap.