lowerunit leaking ?? 1988 force 85hp

[WaveJumpingMaxum]

Ok first off, I lost power from hurrican irene for 61/2 days, I apologize to anyone trying to help on my old threads if i didnt get a chance to reply. Secondly heres my issue, ive had accelartion problems in my boat since day 1. Have to punch it wide open it kinda clears out then takes off, would do 30-35 on rough water with 2x 31 series batteries and 2x people, tried adjusting the carbs, fuel pump diaphram and other things. When i pulled the boat out for the storm a couple weeks ago i notice oil dripping out of my lower end when i got home. it had always done it but i thought it was comming from the exhaust and having owned 2stroke dirtbikes that occasionaly had similar issues i figured it was normal. i also noticed that some of the oil was milky in color , pointing to water mixed in with it. I saw a screw labeled vent and one labeled fill. is changing the lower end fluid as simple as taking one out and draining then filling? or am i missing something. could this be my accelartaion problem all along?

 

[Karla45]

Re: lowerunit leaking ?? 1988 force 85hp

It depends on your lower unit. If the vent and fill plug are right next to each other at the top of the lower case there should also be a plug at the very bottom of lower unit facing ground. In this case you would unscrew bottom plug and also vent plug and drain. Once it is drained then you place the pump in the fill hole and fill until oil comes out of the vent hole. If on the other hand if you have 1 plug at the top of the lower that is vent plug and the drain/fill plug is at the bottom then you need to fill from the bottom until oil comes out the vent hole. Hope this does not confuse you. Also, put new seals the screw plugs everytime you change lower unit oil. I had a leak coming in my lower at the fill plug because seal was old. I also had a leak coming from the seals below waterpump on my 85hp 1989. What area of the lower do you see oil coming from? Around the prop area or up higher? Mine was coming out of the weep holes below cavitation plate.

 

[WaveJumpingMaxum]

Re: lowerunit leaking ?? 1988 force 85hp

I have the setup where its the two plugs next to each other near the top of the lower unit. I have a skeg?? not sure if thats the right term but its fin looking thing for stability on the top part of the lower unit. Not nessicary cause i have power trim so my first step will be removing it. The oil looks like its comming from the vent plug and where the lower unit meets the rest of the engine. Thats also right where the skeg is so its kinda hard to determine. Ill post pictures of where its comming from in the daylight if its not too rainy.

 

[tater76]

Re: lowerunit leaking ?? 1988 force 85hp

Your "skeg" is actually the very lowest fin on the lower unit (the bottom) points vertically. The fin you mention is it plastic bolted to the lower? lays horizontally? Sounds like a whale tail, or "hydrafoil" to be correct. The oil you see may just be from the drain/weep holes that are supposed to be there, and yes they will weep oily residue. Pics will help.

 

[Karla45]

Re: lowerunit leaking ?? 1988 force 85hp

The skeg is on the very bottom of your lower unit under the prop not directly under prop but back a little. There is what is called an exhaust snout that looks like a fin too it serves as a trim tab so if you remove it you need to mark the position for reassembly. I think this is what you might be referring too, it is on the upper part right under the cavitation plate. do you have your serial number this will help you because you can find diagram on boat.net of you lower unit. There are steps you need to take before you start taking things apart. If you have a leak coming from the vent plug then buy a new seal they only cost about .75 and it should stop the leak. You can buy at any boat shop that sells mecury parts. If you search my posts you will find alot of information on this whole issue with lots of pictures. Read through them they may help. To check for water in the lower unscrew drain plug at very bottom and see.

 

[Karla45]

Re: lowerunit leaking ?? 1988 force 85hp

Oh and also there is also a screw on the same side of the lower unit where the vent & fill plugs are that you should not mistake for drain plug or you will have to take the whole lower unit apart. It is on the side close to the bottom and is a small screw inside a hole.

 

[WaveJumpingMaxum]

Re: lowerunit leaking ?? 1988 force 85hp

ok i know its hard to see but the shiney part on there is oil. if you look at the lip right under the fill and drain plug it is the lip where the whale tail is. Right under that lip are a bunch of tiny holes im guessing this is where it should seep out of like you said?? once my batt is charged ill lift the engine and get pics under the lip couldnt do it now sun is directly above boat.

 

[Karla45]

Re: lowerunit leaking ?? 1988 force 85hp

Do not worry about taking a picture the holes you are talking about are weep holes. From what I have been told it is also possible that this is unburnt oil from engine. The way I figured out if it was unburnt oil or gear oil is I wiped all the oil off the side and then waited and gave time to leak some more. When it started to leak again I took a white napkin and wiped off to see what color the oil was and I also smelled it. It should smell like sulphur if it is lower unit oil. I am not sure of the condition of the oil in your lower right now but I would drain it and refill with new oil, then put the new seals on the plugs. If you saw oil coming from one of the plugs then that could possibly be where the water came from. You could also drain the oil and do what is called a pressure test to see if you have a leak. You will need a gear oil pump that you can buy at walmart for fairly cheap in order to fill it up. Also, have you smelled the oil that is on there right now to see if it smells like sulphur? Also in your first picture you can see the hole and screw I was talking about when I said do not remove, that is not the drain plug. From looking at the picutures I did not see that it looked like oil was leaking from them but I may not be able to tell from the picture.

 

[WaveJumpingMaxum]

Re: lowerunit leaking ?? 1988 force 85hp

ok i let it sit for a while went out to see more oil dripping out. #1 spot its comming out of is the screw you told me not to remove. #2 the weep holes and #3what appears to be the bolts next to the weep holes that hole the lower unit on. Didnt really smell sulfer and the oil was black. When i first pulled the boat I had milky oil, like there was water mixed in. where the screw you told me not to remove is. Hopefully harbor freight sells lower unit pressure testers.

 

[Karla45]

Re: lowerunit leaking ?? 1988 force 85hp

Get a clear jar or glass and unscrew the drain screw at very bottom of lower unit the screw will be facing down and will be same size as your vent & fill screws. Let some of the oil flow into the jar. If there is water in it then the water will seperate from the oil and you will be able to see this, also you will be able to see better if the oil is milky. If the oil is milky then there is water in it for sure. You really do need to drain the oil out if you have seen it looking milky. I am not sure if harbor freight has what you need and I think a pressure tester might be pretty expensive. I ended up making my own with bike foot pump, gear lube pump, and tire valve. Search homemade pressure tester and you will see what other people have done to make one. There are steps to the pressure test, so if you make one yourself ask here on the board and someone will tell you what to do. Lower unit oil is not typically black but I have heard of people draining lower unit oil and it is black which may mean it is very old or something, I am reallly not sure. Maybe somebody will chime in here and give you some answers.

 

[WaveJumpingMaxum]

Re: lowerunit leaking ?? 1988 force 85hp

cant find the drain plug. theres nothing at all on the bottom of this lower unit. maybe im missing it or have a diff model. this is a 1988 with power trim, 85hp. anyone know of this model having the drain plug in a different spot?

 

[Karla45]

well i think it should be like mine. It is kind of on the side of the bottom not directly facing the ground but close you may have to trim the motor up to see it. I had a hard time finding the one on mine first by just feeling around but when i trimmed motor up I found it. Your lower case looks exactly like mine. I have a 1989 85hp.

 

[WaveJumpingMaxum]

Re: lowerunit leaking ?? 1988 force 85hp

ok i found the plug and drained it. it was automotive gear oil. color was roughly 1/2 black and 1/2 brown penut butter color. it looked like it had never been changed. im guessing the brown was from the oil overheating and cooking to a grease type substance. filled it back up with fresh sae 90 marine lowerunit oil. gonna run it once or twice on the water and flush it again see what i get. anyone know what would turn the gear oil brown please let me know as my only guess is the overheating one.