I accidentally added 2 quarts of 2-stroke oil directly into our 4-stroke 100HP Mercury motor. It was not mixed with the gas – it went directly into the motor. The good news (I think) is that there was already a fair amount of 4-stroke oil in the crankshaft – it was about half full already. Do I need to drain it all and replace with 4-stroke only, or can I just let it run its course and gradually add more 4-stroke to decrease the ratio? (I’m a newbie to boat maintenance, if you can’t tell... taking over for my husband - so go easy on my lack of knowledge!)
Added 2 stroke oil to 4 stroke boat motor - oops!
- Thread starter lbry9062
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I would definitely drain it out and replace with the correct oil. 2 cycle oil has a completely different composition than regular motor oil.
Originally Posted By: anonobomber
I would definitely drain it out and replace with the correct oil. 2 cycle oil has a completely different composition than regular motor oil.
+1 Drain and replace with the proper 4 stroke oil.
It would be an interesting experiment to run, 2 stoke oil in a 4 stroke motor, but not with your expensive boat motor...
I would definitely drain it out and replace with the correct oil. 2 cycle oil has a completely different composition than regular motor oil.
+1 Drain and replace with the proper 4 stroke oil.
It would be an interesting experiment to run, 2 stoke oil in a 4 stroke motor, but not with your expensive boat motor...
Absolutely drain the crankcase and refill with the proper oil before running the engine. I would consult Mercury for the recommended oil if you do not have the owner's manual available.
MolaKule
Staff member
Originally Posted By: anonobomber
I would definitely drain it out and replace with the correct oil. 2 cycle oil has a completely different composition than regular motor oil.
Yes, replace ASAP.
I would definitely drain it out and replace with the correct oil. 2 cycle oil has a completely different composition than regular motor oil.
Yes, replace ASAP.
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http://www.jamestowndistributors.com/mobileportal/show_product.do?pid=97807
Mercury recommends changing every 100 hrs of service. If your not sure when it was last changed it would be wise to do so. Cheap insurance.
Open up the "tech specs" and you should find your filter (assuming that's what you have).
Fortunately Mercury filters are a one size fits most so you should be able to find them pretty easy.
Mercury recommends changing every 100 hrs of service. If your not sure when it was last changed it would be wise to do so. Cheap insurance.
Open up the "tech specs" and you should find your filter (assuming that's what you have).
Fortunately Mercury filters are a one size fits most so you should be able to find them pretty easy.
Originally Posted By: lbry9062
Thank you, everyone. Unfortunately, we did run the motor for about a half hour. Hopefully I haven't caused damage.
Its fine, keep in mind the base oil is the same stuff, but I would change it out
Thank you, everyone. Unfortunately, we did run the motor for about a half hour. Hopefully I haven't caused damage.
Its fine, keep in mind the base oil is the same stuff, but I would change it out
MolaKule
Staff member
Originally Posted By: Bluestream
Originally Posted By: lbry9062
Thank you, everyone. Unfortunately, we did run the motor for about a half hour. Hopefully I haven't caused damage.
Its fine, keep in mind the base oil is the same stuff, but I would change it out
Not true.
Originally Posted By: lbry9062
Thank you, everyone. Unfortunately, we did run the motor for about a half hour. Hopefully I haven't caused damage.
Its fine, keep in mind the base oil is the same stuff, but I would change it out
Not true.
Originally Posted By: MolaKule
Originally Posted By: Bluestream
Originally Posted By: lbry9062
Thank you, everyone. Unfortunately, we did run the motor for about a half hour. Hopefully I haven't caused damage.
Its fine, keep in mind the base oil is the same stuff, but I would change it out
Not true.
You're right, the 2 stroke probably has a better base oil.
Originally Posted By: Bluestream
Originally Posted By: lbry9062
Thank you, everyone. Unfortunately, we did run the motor for about a half hour. Hopefully I haven't caused damage.
Its fine, keep in mind the base oil is the same stuff, but I would change it out
Not true.
You're right, the 2 stroke probably has a better base oil.
MolaKule
Staff member
Originally Posted By: Bluestream
Originally Posted By: MolaKule
Originally Posted By: Bluestream
Originally Posted By: lbry9062
Thank you, everyone. Unfortunately, we did run the motor for about a half hour. Hopefully I haven't caused damage.
Its fine, keep in mind the base oil is the same stuff, but I would change it out
Not true.
You're right, the 2 stroke probably has a better base oil.
That's not the real concern.
The add pack is insufficient for a four-stroke and the base oil mix is not a proper mix.
Originally Posted By: MolaKule
Originally Posted By: Bluestream
Originally Posted By: lbry9062
Thank you, everyone. Unfortunately, we did run the motor for about a half hour. Hopefully I haven't caused damage.
Its fine, keep in mind the base oil is the same stuff, but I would change it out
Not true.
You're right, the 2 stroke probably has a better base oil.
That's not the real concern.
The add pack is insufficient for a four-stroke and the base oil mix is not a proper mix.
change it out immediately!!! 2-stroke oil will start to burn off and leave carbon deposits all throughout the engine! your oil passages might clog up which inhibits flow, reduces lubrication, reduces engine cooling, and causes wear! 2-stroke oil flash point
is much lower than 4-stroke oil...
do a flushing oil change to get the remaining 2-stroke oil out...I'd say run it to warm oil and drain (and replace the filter); refill with your preferred 4-stroke oil & filter
is much lower than 4-stroke oil...
do a flushing oil change to get the remaining 2-stroke oil out...I'd say run it to warm oil and drain (and replace the filter); refill with your preferred 4-stroke oil & filter
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Originally Posted By: ragtoplvr
change it. There is little chance of damage in short term use. Since many 2S oils are diluted, the dilutant burns off and the level will fall fast.
Long term, there are no PH buffers, no detergents, it will not be good.
Rod
JASO FD two cycle oil does have detergents (keeps powervalves clean). Nevertheless, agree that it's a poor oil for the four stroke outboard. Simply drain it and re-fill with correct oil. Half hour run time not ideal but all should be OK.
change it. There is little chance of damage in short term use. Since many 2S oils are diluted, the dilutant burns off and the level will fall fast.
Long term, there are no PH buffers, no detergents, it will not be good.
Rod
JASO FD two cycle oil does have detergents (keeps powervalves clean). Nevertheless, agree that it's a poor oil for the four stroke outboard. Simply drain it and re-fill with correct oil. Half hour run time not ideal but all should be OK.
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Drain it and change the filter. Refill with correct oil and do a short OCI then change it and filter again to remove all traces of the two stroke oil.
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