Reposting for more feedback if allowed
Ongoing issue with my 2018 Mercury ProXS 150, unit cuts out,sputters under moderate to heavy acceleration

Quick update...after a total of 3 weeks downtime in both locations of a local dealer( in Hurst and Cleburne) but no names ....I have been told they found all 4 plugs were fouled and needed replaced...when I pressed them a little I was told that during break in it is programmed to double oil for extra lube...ok I knew that..but unit is not in "break in mode" any longer...so basically I have a Mercury that only has 24 engine hours and is 8 months old that I am being billed for...sound crazy or is it me?
And by the way...no codes and fuel rails were said to be fine

You could have manually put it in break in mode by accident, moving the throttle forwards & backwards a certain number of times does it manually. If not you, maybe a kiddo?


Do you ever run it hard or do you idle a lot?

How is that motor not under warranty if it's that new?

I run the boat hard but not abusive...no kids in the picture and has a hot foot , plus the tech said it had gone through break in and was out of the break in mode,

I guess really the whole confusion is being told by a certified Mercury shop is that "Mercury says you have to replace the plugs after break in because it fouls the plugs" that's just a hard statement to follow ..let's design a engine with break in software that intentionally fouls plugs and cost the consumer...come on

I�m confused a little. Are you not being covered by Merc for warrantee work needed on a motor that by your description should clearly still be under warrantee? Did you have the plugs replaced the first time in and now are being told you need to have them replaced again? First off plugs are not a warrantee item BUT what is causing them to foul certainly is. Every new motor I have had involved a �double oil break in period�. When it wasn�t a programmed feature you simply added oil to your tank to force the oil injection to double the oil. I have always been shocked that the double oil thing didn�t cause plug fouling issues for me but it didn�t. I never had to replace plugs just because of break-in but certainly can see how it could happen. I was always surprised that the process didn�t cause me problems actually. The question is have the plugs been replaced AFTER the breakin period and the problem keeps reoccurring? If not I would stick in a set of plugs and see if your problem is not fixed. If the plugs have been replaced AFTER the breakin period and the problem is still reoccurring clearly you have a warranteed issue. I agree that sould not be on your dime but read the �small print�. Plugs are one of those excluded items �designed to wear out�. I understand your frustration completely but it�s like when you bring in your several month old �brand new� pickup truck back to the dealer with a sidewall blow out on the tire. �Not covered�. Completely understand your frustration and good luck!

It sounds like he doesn�t believe he should pay for,replacing spark plugs. Break in on a 2 stroke if done correctly almost always fouls the plugs. Warranty doesn�t cover service issues like spark plugs.
It costs money to own a boat.

Yes, you took a boat in to have the fouled plugs from break in swapped out. Yes you are being charged. Just because it�s a new boat doesn�t mean there�s no owner required maintenance.
I had To take my new boat and put around and break it in then spend 500$ to service it and get the break in oil replaced. Next time swap them yourself

Just like on the new sho if you don�t grease the mid section per the required maintenance and it goes out it�s not warrantable and about a 6000$ fix. And yes if you take it in they will charge you to grease it

Agreed, most always fouls plugs during break-in, haven't always had to replace, but certainly have to clean/ inspect them afterward.

Wow..guess I wish I had the inside you have...might have to slow this down a bit so you can catch up...after 30 years of boat ownership I have a pretty good handle of the cost of boat ownership and maintenence..the underlying issue is the story I'm having a hard time understanding....that due to doubling oiling we expect your spark plugs to foul out within the break in period and due to mercury marines software you will pay to have spark plugs replaced...its only 24 engine hours old....its not the cost it's the philosophy ...but thanks anyway for your meager input...this case is closed

Wow..guess I wish I had the insite you have...might have to slow this down a bit so you can catch up...after 30 years of boat ownership I have a pretty good handle of the cost of boat ownership and maintenence..the underlying issue is the story I'm having a hard time understanding....that due to doubling oiling we expect your spark plugs to foul out within the break in period and due to mercury marines software you will pay to have spark plugs replaced...its only 24 engine hours old....its not the cost it's the philosophy ...but thanks anyway for your meager input...this case is closed

Didnt get the support group you needed? No group hug? I agreed with you being upset over what was/wasn�t covered while others did not. Is everyone in life �meager� who does not agree with you and hold your hand?

I think all motors have to have the plugs changed after break in, my old azz 2000 Yamaha had to have the plugs changed after break-in.