hey. i have an old johnson 5HP motor we use with a small boat. I want to change the oil, but im not really sure how to do it.... on our bass boat, i used a special pump that i borrowed from the local fishing shop. but on this small motor, i think i can just turn the motor upside down and pour oil in it?? also, what oil should i use?? 90 transmission fluid??

Take both plugs out and let it drain. It should the color of the oil or black. It should not be milky tan, this is a water leak.

After draining, fill it from the bottom hole until it starts coming out the top hole. Put the plug in the top hole, then quickly remove what you're putting with and install the bottom plug. Installing the top plug first helps keep the oil from draining back out when trying to intall the top plug.

I use the Penzoil 100% synthetic.

thanx. thats the way we did it with the big motor, but we used a special pump.

with this small motor, can i turn the motor upsdide down, so i can fill the oil from the bottom hole, wich now will be the top hole as the motor is upsides down??

i mean, i know i have to put the oil in the hole close to the propeller. if i turn it upside down, this hole will be the top hole, so i would be able to put the oil without a special pump, just by gravity. when the oil starts coming out of the hole closer to the motor (top hole when the motor is upright) i will close both holes. is there a problem if i do this??

and, what grade oil do i need??

If you want to flip it over to put the oil in, but you don't want to completely fill it. Once you think you have enough, put the bottom plug in and flip it back over and take the top plug out. If oil comes out, let it drain until it quits, if no oil comes out, it not full enough so put the plug back in and flip it back over and do it again.

Look for omc online and follow the instructions given by the manufacturer. If you need something special to change the oil, get it! Just don't half-*** it. Quickest way in the world to ruin something is to not know what you are doing and try to do it anyway. My read............ epic fail......

i borrowed the special pump to change the oil on my bass boat.... but on this small motor, i dont think i need the same tool.... i just took apart the lower unit to replace a seal, since the oil had a little water in it.... you say "Quickest way in the world to ruin something is to not know what you are doing and try to do it anyway" but i prefer this quote: "what we need to learn how to do, we learn by doing it"... i do all my jeeps maintenance, electrical, mechanical, cosmetical..... all i have done to it, i had to learn while doing it... sure, sometimes i would ruin something, but at least now i know how to do it, or how NOT to do it.... so hopefully tomorrow i will get the seal and put together the lower unit, and have the boat running by the weekend....

i borrowed the special pump to change the oil on my bass boat.... but on this small motor, i dont think i need the same tool.... i just took apart the lower unit to replace a seal, since the oil had a little water in it.... you say "Quickest way in the world to ruin something is to not know what you are doing and try to do it anyway" but i prefer this quote: "what we need to learn how to do, we learn by doing it"... i do all my jeeps maintenance, electrical, mechanical, cosmetical..... all i have done to it, i had to learn while doing it... sure, sometimes i would ruin something, but at least now i know how to do it, or how NOT to do it.... so hopefully tomorrow i will get the seal and put together the lower unit, and have the boat running by the weekend....

You need to do it from the bottom up just like on you other motor. The pump I have costs $2.99 and it screws onto the oil bottle. They also sell the gear lube in a bottle that will screw in the bottom hole. It's kind of like a big tube of tooth paste. Just don't try to pour it in. It's filled from the bottom up for a reason. Doing it any other way will cause it to be only partially filled and turn your motor into an anchor.

I agree about doing things yourself and that being a great learning tool. I'm sure that you at least "glanced" at the instructions when doing work on your jeep! Like crab said above, the reason you fill it from the bottom up is to insure you have the correct amount of gear oil in the lower unit and the incorrect amount of oil will be costly!

thanx, thats what i wanted to know.... unfortunately im not in the US, an di havent seen that pump anywhere here... but i guess i can borrow it again...

and yes, i looked at instructions or asked for advice... and thats exatly what i am doing here....

so, what oil do you use?? the same oil used for std transmissions?? for my jeep i use 90 for the transmission and 140 for the diffs.

thanx.

Maybe some of the OMC guys will chime in but I would do some research and find the right marine grade lube specifically formulated for your outboard.

The reason the oil needs to be put in from the bottom is to purge the air out the top as you fill. For a small motor you can pump it in the bottom or just put the spout of the oil tube in the bottom and squeeze. When oil comes out the top put the top screw in quickly.

Not sure what country you are in, but you need to purchase OMC lower unit oil. Where you got the seal would be a good place to look for the oil.....Al

thanx... ill try to find it... i have never heard of that oil though... im in Mexico BTW...

Well, I'm sure there are many experts on here that know way more than me, but since I don't know any better I just do things my way. I can buy a quart of Vavoline full synthetic a hellavalot cheaper than I can buy BRP oil. When doing four LU's that hold 44oz's each twice a year and six more smaller motors, that's adds up. My two 300+ hp hotrod motors have lived on Penzoil for about 8 years now, and still going strong. My old 99 225 Ficht with the lightning gearcase hasn't exposed any internal parts yet, with Vavoline in it, and those things can blow just for lack of something better to do. There is not an OMC motor made you can't use the synthetic in. PLEASE note, I said OMC, not BRP, not Mercury, not Yamaha etc.

Now, if I went down a bought a brand new e-Tec, no, I would not use Vavoline in it, at least not until the warrenty ran out. There are a lot of the new motors you can't use it in, a lot of the Merc's require their special hypoid gear oil and you will smoke one of those.

MADE A BIG OOP's I use Valvoline 100% synthetic