Just had the 6 year service done and the shop put 25 W40 in it….I’ve always used 10 W30. Took the boat out for the first time since service yesterday and it felt a little sluggish and top end was off 2-3mph. Water temp was in the mid to upper 40’s. Air temp started in mid 40’s and ended in upper 60’s. Would the thicker oil cause this sluggish condition?
2019 721 ProXs 4S 250
2B599739
puts a lot more drag on the oil pump-- one of the reasons todays cars use such light oil grades
you should have 10-30 in there
2022 z519 cup 225 merc 4s ser # 3B210484. 2--hds12 live units. 2 poles, atlas plate, ghost, hamby's, active target, merc digital gauges
2002 basscat pantera 3 (dad bought new) sold 8-2-22
2000 stratos 20 ss (bought new) 200 hp Rude ficht great boat/motor sold 11-21
pulled by a 2500HD Denali will all the BANKS upgrades
MAGA 45-47
ASE/GM Master tech before tools
To be honest, any mechanic that doesn't follow directions from the engineers who designed the motor probably shouldn't be working on your boat.
Thanks for the input guys and I tend to agree...10 W30 is what I put in when I do it myself. I am still wondering if that could cause a sluggish feel to the power output.
2019 721 ProXs 4S 250
2B599739
Using an oil that is higher viscosity than needed can definitely reduce power output of an engine. This has been shown in automotive dyno testing. I would expect it to be most noticeable in cold weather.
David Patten
Automotive and marine technician.
Could have come and visited us.... sure would have got you the right oil!Originally Posted by Triton19x2
I would strongly recommend you change it again with the CORRECT, 10w30 Synthetic Blend oil.
Did they replace thermostat, belt, plugs, water pump as well?
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 48 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Yeah I know Don, I should have sucked it up and made the pilgrimage over to see you.�� All the other things were done. I’ll reach out to Rhonda and get the oil and filter ordered.
2019 721 ProXs 4S 250
2B599739
drain oil and filter and refill with correct grade fine. new filter not needed but up to you of course!
2022 z519 cup 225 merc 4s ser # 3B210484. 2--hds12 live units. 2 poles, atlas plate, ghost, hamby's, active target, merc digital gauges
2002 basscat pantera 3 (dad bought new) sold 8-2-22
2000 stratos 20 ss (bought new) 200 hp Rude ficht great boat/motor sold 11-21
pulled by a 2500HD Denali will all the BANKS upgrades
MAGA 45-47
ASE/GM Master tech before tools
2019 721 ProXs 4S 250
2B599739
This has me thinking about draining the 25w40 synthetic blend I just added in the fall and trying out 10w30 synthetic blend this upcoming season. Previous owner always used 25w40 since the engine was new in 2012, so I stuck with that. I've been trying to squeeze whatever performance I can out of the engine with prop testing, etc. but now I have to wonder if the oil itself could make a difference. 150 fourstroke.
Cashcrews
2012 150 Fourstroke
Model: 1150F23HD
SN: 1B925179
Different engine- remember we must keep threads to one (1) poster-engine combination so as to help avoid confusion and/or post hi-jacking.
That said- 10w30 Synthetic Blend is what I would recommend, especially in your climate.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 48 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Personally I don't think heavier oil would cost you 2-3 mph........
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