S/N 2B637230
Was out for the first time today. Motor started fine but I noticed that at idle and at low RPM’s the motor would run rough and I noticed it shaking more than usual.
what could be likely or possible issues and things I should inspect or try?
How many hours do you have on your engine (currently)? Maintenance History?
Visual inspection is a good starting point- also spark plug inspection (and/or any other maintenance that might be due).
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
I had the same problem with my new 2021 ProXS 4 stroke 225 but it didn’t last long. I have only 8 hours on mine. I repowered on a 2003 ranger 520vx. I wonder if it was due to some possible moisture in my gas tank and will need to be ran out. Makes me nervous with a brand new engine! But hopefully you don’t have any major issues on yours, I’ll let you know if it comes back on mine
Two seasons at 10-15 hrs each season...so 20-30 hrs total? Weekend angler.Originally Posted by EuropeanAM
Oil change and lower lube completed at end of both seasons.
Will check spark plugs.
I do wonder if it is foul or old gas? I do use stabilizer but sometimes I wonder how well mixed it gets if I dump it into the tank and it not get stirred around.
Poor fuel quality is definitely possible- even stabilized, fuel really shouldn't be run if it's more than about 4 months old.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Spark plugs all snug. Should I pull to inspect?
Yes, plus fuel filter and other outstanding maintenance.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Mel... Spark Plugs are an Annual Maintenance Item (every 364.99 days, or 100 hours of operation, whichever occurs FIRST). There is also a pretty comprehensive list of other items that should be serviced or maintained at that interval: See the link below for more info:
Recommended Annual Maintenance for Optimax Engines
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
I thought the same thing years ago with the plugs in my V8 MasterCraft, 30-50 hours annually? What? The second year I had that boat I changed the plugs and noticed a real difference in starting and performance. I change them every year now. Where I REALLY noticed a difference was when I replaced the plug wires the next year. I put that on a 3-year schedule now.
Not sure what the schedule is for plug wires is on the merc 4-stroke, but plugs/wires likely can be a culprit. I'd be interested in resistence testing of wires between start and end of season.
I have a 2018 Ford Fusion and it calls for spark plug replacement at 100,000 miles so I can see why one would question 100 hour/ annual replacemet of spark plugs......but like I indicated, made a noticible difference in my V8 boat. Maybe I should be changing the plugs in my Fusion Hybrid more often??
2015 Tracker Targa V18 150 4-Stroke 2B142247 9.9 EFI Pro Kicker 1R159535
2001 MasterCraft Maristar 210 V-Drive, LTR 330 HP
Hey thanks JS! I am in the process of replacing the plugs with the plugs that are indicated on the side of the motor...NGK-LKAR7C9.
i understand the allure of iridium plugs but if we are being asked to replace plugs annually, I will not be using the iridium versions as they are not cheap!
A question for this board...be honest...how many of you are changing your plugs annually and using iridium?
Also just wish there was a more straight ahead way of diagnosing...my plan is to replace plugs, replace water separating fuel filter. Hope it will be back to normal. Pulling my plugs I could see quite a bit of soot on all of them but unsure if it was worse than should expected.
Wish me luck.
Last edited by BoilermakerZ519; 05-02-2021 at 09:19 PM.
Do NOT use any plug other than the one recommended by the manufacturer.
If you substitute another plug and have problems with the engine, you may be left holding the bag for whatever happened.
I can answer for a WHOLE lot of folks on this board since for a pretty good number of them, either I change their plugs OR Rhonda ships them to them so they can change themselves.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
I think I confused an old thread that you put out Don that identifies the spark plug recommendations by engine type. It says it was updated in 2020 so I figured this section included my engine.
from: http://www.bbcboards.net/showthread.php?t=20401
<Edit- Removed to prevent possibility of future confusion>
I too thought this was odd that it was different from what was listed on my engine. Maybe the reference thread should be clarified to include the V8 models. My 225 Pro XS uses NGK-LKAR7C-9.
Regardless, thank you for the suggestion on changing the plugs and fuel filter. Installed them and ran her today. She runs better than she did new!
I remain surprised that these motors burn through spark plugs with less than 30 hrs of use. Maybe I run it harder than average. Idk.
thanks again Don.
Last edited by EuropeanAM; 05-05-2021 at 11:10 AM. Reason: Referenced 2-Stroke engine info rather than 4-STROKE
The quoted portion above is from the 3L 2-stroke forum which obviously doesn't apply to 4-strokes. "ProXS" is a model in an engine category and it existed long before the current 4-stroke models were introduced.
_______
Phil
'09 Hewescraft ProV
'09 150 Optimax
+1
When searching for common topics- always look at the FAQ Section in the CORRECT FORUM. The thread you referenced does not contain one single 4-stroke engine, because it came from a 3L (2-Stroke) forum.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
got it...yep I just googled “4 stroke 225 pro xs bbc.com” and it came up. Thanks for that heads up.
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