is it a 2 stroke or 4 stroke

[gatortwins]

i,m looking at a 2002 25hp mercury motor that the owner inheritied from a family member and they know nothing about it.i can tell the motor has been used very little.my question is how can i tell if it is a 2 stroke or 4 stroke.i want to here this motor run but i dont know how to mix or not mix the fuel.there,s nothing on the cover or motor that tells me anything.it is a 2002mercury 25e hp serial#ot559438 model#1025302ZD weight-114lbs

 

[Silvertip]

Re: is it a 2 stroke or 4 stroke

An outboard is generally a two stroke if it DOES NOT say four-stroke on the cover. But to make sure, remove the cover. If the engine has a resevoir on the side that has oil in it, it will be a two stroke. If it doesn't, look around the engine and see if you can find an oil filter and a dipstick. If you find them it will be a four stroke. Four stroke engines do not require mixing fuel and oil injected two strokes don't either as its done automatically. Four strokes are just like the engine in your car -- you need to check and change oil and filter at regular intervals. If you don't know what a dipstick and oil filter look like, have one of your more boat savy friends identify it for you. I suspect you have a two stroke however.

 

[gatortwins]

Re: is it a 2 stroke or 4 stroke

thanks for the info.so an oil injected 2 stroke should also have a dipstick and filter.i thought maybe the ot in front of the serial# might be the code for oil injected.

 

[jay_merrill]

Re: is it a 2 stroke or 4 stroke

I'm reasonably sure that what you have is a carbureted, two-stroke outboard.

Go ahead and look for the presence of an oil dipstick, indicating that it is a four-stroke, but I don't think you are going to find one. Do the same for an oil tank. I don't know Mercury outboards very well and am assuming that any 2002 two-stroke model would be oil injected, but I suppose that its possible that it is not. If that is the case, you won't find an oil tank, either.

You might also want to pose this question in the Mercury forum - the folks there will probably be better informed.

 

[Don S]

Re: is it a 2 stroke or 4 stroke

If you have the proper SN posted "ot559438" then it IS a 2 stroke.

 

[Silvertip]

Re: is it a 2 stroke or 4 stroke

NO! An oil injected two stroke does not have an oil filter or a dip stick (they don't have oil in the crankcase like a car). The oil resevoir on a two stroke may have a dip stick but the tanks are generally opaque so you can see the oil level. Oil in a four stroke is contained inside the engine.

 

[Home Cookin']

Re: is it a 2 stroke or 4 stroke

also, few smaller or older 2 strokes have oil reservoirs so while the presence of one means 2 stroke, absence does not mean 4 stroke.

I realize Don answered the question this is just for the topic.