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Author Topic:   1995 Mercury 90-HP Leaks Oil From Reservoir

twista posted 04-17-2009 01:38 AM ET (US)
[Are the O-rings in the cap of the oil reservoir in a 1995 Mercury 90-HP two-cycle motor prone to leaking when the engine is in the fully tilted-up position? Are two O-rings used to seal this cap?]
jimh posted 04-17-2009 08:59 AM ET (US)
Oil should not leak from the oil reservoir when your outboard motor is in the fully tilted-up position. You may need a new cap.
twista posted 04-17-2009 03:12 PM ET (US)
Will replacing the O-ring fix the leak? Should I just replace the whole cap?
FISHNFF posted 04-18-2009 03:24 AM ET (US)
I had a 1996 Merc 75 2 stroke with the mentioned oil leak from the cap when tilted.
I changed "O"-ring 3 twice.
I replaced entire cap assembly.
It would leak some of the time. Tightened tightly or snugly. No rhyme or reason to it leaking.
I finally sold it because I got so upset.
I thought about replacing the entire oil reservoir.
Best of luck.
FISHNFF
Newtauk1 posted 04-18-2009 10:00 AM ET (US)
Same problem with my 2001 75hp Mercury. It is terrible. Oil everywhere. Mercury has offered NO HELP. Replaced the filler cap. May need to replace the oil tank. This problem started when new.
conrjm posted 07-02-2009 10:39 PM ET (US)
Yes. [My Mercury outboard engine has] the same problem, and it is killing me. It appears that the leak is from the oil reservoir fill. I have replaced the cap with a new factory original cap. It still leaks when tilted forward. Not when the engine is down. The cap seems to have been engineered without any thought as to how it would be used. First of all, when you tighten the cap a bit too much, it skips the thread and gets loose. Secondly, when the engine is tilted forward, the fill cap is under the oil level, allowing this terrible design the opportunity to leak. It would be sensible to use a cap more like a gas cap, or a car radiator cap. They don't leak. Or they could put the fill on the aft corner of the tank so it will not be submerged under the oil when tilted forward. Am I asking for too much?
Can anyone suggest how I might fix this leak? Besides swearing off Mercury outboards? Thanks!
Newtauk1 posted 07-03-2009 08:21 AM ET (US)
I went through this from day one with a New 2001 Mercury 75hp. Mercury claimed I over tightened the filler cap and thus my fault. I have replaced the cap and o-ring with no improvement. I now tape a sock over the cap to soak up the oil. The cowling foam was been saturate with oil from day one. I am always cleaning it up. I also try to keep the oil level low in the tank. This is what my Mercury Certified mechanic suggested. I called Mercury this spring to see if there is a new improved oil tank. There is not. Mercury told me to buy a new oil tank. I asked the Mercury Rep why I would do that if the design had not been changed or improved and she stated that's what they have been told to suggest.
I also keep a oil absorbing Spill Sock in mt transom well.
Mercury is ignoring the fact that the design is poor and faulty. Their design is dumping massive amounts of oil into the oceans, rivers and lakes and they do not care. I most likely will not buy another Mercury again. I hope someone files a class action law suit against them. They deserve to go out of business. Until then I keep cleaning up oil.
conrjm posted 07-21-2009 08:08 PM ET (US)
I went to my local mechanic, who at first was unfamiliar with the problem, but when he called around, several of the neighboring guys knew about it. They said Mercury is pretending it isn't really happening, and we all have wild imaginations. They won't do a thing. My mechanic used a 2-inch hose clamp around the neck of the oil fill. It is not a perfect fix, but so far it helps. Be careful not to make it so tight you can't get the fill cap off. I am with anyone who can start a class action suit. Mercury is responsible for all the environmental damage this problem is causing.
Newtauk1 posted 07-22-2009 12:41 AM ET (US)
The marina that I keep my boat a has suggested buying anything but Mercury. They are a Mercury certified dealer. they prefer Suzuki.
Newtauk1 posted 07-22-2009 12:45 AM ET (US)
Oil continues to leak from all the Mercury 2 stroke motors I see at the marina, It is terrible. Oil on the water.
ROBBCO1 posted 07-09-2012 10:37 AM ET (US)
For leaking oil problems on Mercury engines - check out the "Merc BUDDY" on Ebay.com or at www.robbco-llc.com for a fix to this problem.
Gatored posted 07-07-2014 11:49 AM ET (US)
I found the perfect solution for a leaking 2 cycle oil container on my 1996 75 HP Mercury. I bought at Home Depot a 2 inch rubber PVC cap. It is made by Fernco It is a PQC-102. SKU 1857800049.
This is the real deal, remove the Mercury cap, place the rubber cap over the opening, tighten the clap with a screw driver, you will never have a leaking problem again. I fill the container to the top, tilt all the way forward and trailer across Florida with no leaks!!! Good luck. Hope this helps frustrated Whaler Owners
Don SSDD posted 07-07-2014 07:27 PM ET (US)
Looks like a great option. Not on their site in Canada, but if you search there for FLEXIBLE CAP they have a similar Pro Connect.
Can you remove it without removing the cowl?
Don
Gatored posted 07-07-2014 10:47 PM ET (US)
Yes, Don you have to remove the cowling. But not having to deal with the mess is well worth the little bit of effort. My first experience with the leaky cap was blue smoke pouring out of the engine as soon as we launched the boat and started the motor (I had the motor tilted all the way forward for the ride to the ramp). The oil had sucked into the carbs from inside the cowling. It was the worst experience at a boat ramp ever. I could not find a Lilly Pad large enough to hide under. Took the boat home and spent an hour mopping the oil out of the inside of the cowling.
Gator Ed
Alan Heckman posted 07-08-2014 07:08 AM ET (US)
I had a 2005 Mercury 75 HP. 2 stroke and had the same problem,it drives you crazy. Over time the tank neck gets stretched and no matter how much you tighten it , it still will leak oil. After trying many things I added a second O ring and voila, problem fixed for less than $1 ! The only other fix is a new oil tank for $$$$$$$.
swist posted 07-08-2014 07:56 AM ET (US)
Amazing how they can design parts of the interior of the engine to very tight tolerances and have them withstand (most of the time) years of all types of mechanical stress, and not get a cap right. It can't be the same people.
sosmerc posted 07-09-2014 01:39 AM ET (US)
I feel your pain. I see this issue ALL of the time with practically All of the inline 3 and 4 cylinder 2 stroke oil injected Mercs. It's a very poor design and has never been resolved to any degree of satisfaction. I tell my customers to purposely leave the oil tank level at about 1/2 full, then don't tilt the engine to its max level. Even at that, I always install an oil absorbant cloth all the way across the lower cowl, below and at the front of the engine inside the cowl. It at least keeps the mess to a minimum in the splashwell. By the way, I have also seen this issue with some of the Nissan/Tohatsu oil injected 2 strokes. I guess the plastic tank necks can get easily distorted for one reason or another and then they can leak. I resolved a few leaking issues by putting a hose clamp around the neck and tightening after the cap is installed. It works, but is a cheesy fix in my opinion. Don't really know why Merc didn't try harder to fix the problem. Their small reserve tanks on their larger V-6 engines don't have any issues that I have run into. (and they are plastic tanks with screw on caps with flimsy gaskets, yet they don't leak.
Don SSDD posted 07-10-2014 07:15 AM ET (US)
They could just use a regular screw on cap like the gas cans have, if a gas can lid can take the air pressure generated from a tank sitting in the sun, it should work fine on the oil reservoir.
My 90HP has leaked from the lid for a long time. I "fixed" it using 2 o rings, works good unless you don't tighten it just right. You have to loosen it and re-tighten until you get it to stop leaking.
I am going to try one of these flexible pipe caps, looks like it should work.
Don

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Author	Topic: 1995 Mercury 90-HP Leaks Oil From Reservoir
twista	posted 04-17-2009 01:38 AM ET (US) [Are the O-rings in the cap of the oil reservoir in a 1995 Mercury 90-HP two-cycle motor prone to leaking when the engine is in the fully tilted-up position? Are two O-rings used to seal this cap?]
jimh	posted 04-17-2009 08:59 AM ET (US) Oil should not leak from the oil reservoir when your outboard motor is in the fully tilted-up position. You may need a new cap.
twista	posted 04-17-2009 03:12 PM ET (US) Will replacing the O-ring fix the leak? Should I just replace the whole cap?
FISHNFF	posted 04-18-2009 03:24 AM ET (US) I had a 1996 Merc 75 2 stroke with the mentioned oil leak from the cap when tilted. I changed "O"-ring 3 twice. I replaced entire cap assembly. It would leak some of the time. Tightened tightly or snugly. No rhyme or reason to it leaking. I finally sold it because I got so upset. I thought about replacing the entire oil reservoir. Best of luck. FISHNFF
Newtauk1	posted 04-18-2009 10:00 AM ET (US) Same problem with my 2001 75hp Mercury. It is terrible. Oil everywhere. Mercury has offered NO HELP. Replaced the filler cap. May need to replace the oil tank. This problem started when new.
conrjm	posted 07-02-2009 10:39 PM ET (US) Yes. [My Mercury outboard engine has] the same problem, and it is killing me. It appears that the leak is from the oil reservoir fill. I have replaced the cap with a new factory original cap. It still leaks when tilted forward. Not when the engine is down. The cap seems to have been engineered without any thought as to how it would be used. First of all, when you tighten the cap a bit too much, it skips the thread and gets loose. Secondly, when the engine is tilted forward, the fill cap is under the oil level, allowing this terrible design the opportunity to leak. It would be sensible to use a cap more like a gas cap, or a car radiator cap. They don't leak. Or they could put the fill on the aft corner of the tank so it will not be submerged under the oil when tilted forward. Am I asking for too much? Can anyone suggest how I might fix this leak? Besides swearing off Mercury outboards? Thanks!
Newtauk1	posted 07-03-2009 08:21 AM ET (US) I went through this from day one with a New 2001 Mercury 75hp. Mercury claimed I over tightened the filler cap and thus my fault. I have replaced the cap and o-ring with no improvement. I now tape a sock over the cap to soak up the oil. The cowling foam was been saturate with oil from day one. I am always cleaning it up. I also try to keep the oil level low in the tank. This is what my Mercury Certified mechanic suggested. I called Mercury this spring to see if there is a new improved oil tank. There is not. Mercury told me to buy a new oil tank. I asked the Mercury Rep why I would do that if the design had not been changed or improved and she stated that's what they have been told to suggest. I also keep a oil absorbing Spill Sock in mt transom well. Mercury is ignoring the fact that the design is poor and faulty. Their design is dumping massive amounts of oil into the oceans, rivers and lakes and they do not care. I most likely will not buy another Mercury again. I hope someone files a class action law suit against them. They deserve to go out of business. Until then I keep cleaning up oil.
conrjm	posted 07-21-2009 08:08 PM ET (US) I went to my local mechanic, who at first was unfamiliar with the problem, but when he called around, several of the neighboring guys knew about it. They said Mercury is pretending it isn't really happening, and we all have wild imaginations. They won't do a thing. My mechanic used a 2-inch hose clamp around the neck of the oil fill. It is not a perfect fix, but so far it helps. Be careful not to make it so tight you can't get the fill cap off. I am with anyone who can start a class action suit. Mercury is responsible for all the environmental damage this problem is causing.
Newtauk1	posted 07-22-2009 12:41 AM ET (US) The marina that I keep my boat a has suggested buying anything but Mercury. They are a Mercury certified dealer. they prefer Suzuki.
Newtauk1	posted 07-22-2009 12:45 AM ET (US) Oil continues to leak from all the Mercury 2 stroke motors I see at the marina, It is terrible. Oil on the water.
ROBBCO1	posted 07-09-2012 10:37 AM ET (US) For leaking oil problems on Mercury engines - check out the "Merc BUDDY" on Ebay.com or at www.robbco-llc.com for a fix to this problem.
Gatored	posted 07-07-2014 11:49 AM ET (US) I found the perfect solution for a leaking 2 cycle oil container on my 1996 75 HP Mercury. I bought at Home Depot a 2 inch rubber PVC cap. It is made by Fernco It is a PQC-102. SKU 1857800049. This is the real deal, remove the Mercury cap, place the rubber cap over the opening, tighten the clap with a screw driver, you will never have a leaking problem again. I fill the container to the top, tilt all the way forward and trailer across Florida with no leaks!!! Good luck. Hope this helps frustrated Whaler Owners
Don SSDD	posted 07-07-2014 07:27 PM ET (US) Looks like a great option. Not on their site in Canada, but if you search there for FLEXIBLE CAP they have a similar Pro Connect. Can you remove it without removing the cowl? Don
Gatored	posted 07-07-2014 10:47 PM ET (US) Yes, Don you have to remove the cowling. But not having to deal with the mess is well worth the little bit of effort. My first experience with the leaky cap was blue smoke pouring out of the engine as soon as we launched the boat and started the motor (I had the motor tilted all the way forward for the ride to the ramp). The oil had sucked into the carbs from inside the cowling. It was the worst experience at a boat ramp ever. I could not find a Lilly Pad large enough to hide under. Took the boat home and spent an hour mopping the oil out of the inside of the cowling. Gator Ed
Alan Heckman	posted 07-08-2014 07:08 AM ET (US) I had a 2005 Mercury 75 HP. 2 stroke and had the same problem,it drives you crazy. Over time the tank neck gets stretched and no matter how much you tighten it , it still will leak oil. After trying many things I added a second O ring and voila, problem fixed for less than $1 ! The only other fix is a new oil tank for $$$$$$$.
swist	posted 07-08-2014 07:56 AM ET (US) Amazing how they can design parts of the interior of the engine to very tight tolerances and have them withstand (most of the time) years of all types of mechanical stress, and not get a cap right. It can't be the same people.
sosmerc	posted 07-09-2014 01:39 AM ET (US) I feel your pain. I see this issue ALL of the time with practically All of the inline 3 and 4 cylinder 2 stroke oil injected Mercs. It's a very poor design and has never been resolved to any degree of satisfaction. I tell my customers to purposely leave the oil tank level at about 1/2 full, then don't tilt the engine to its max level. Even at that, I always install an oil absorbant cloth all the way across the lower cowl, below and at the front of the engine inside the cowl. It at least keeps the mess to a minimum in the splashwell. By the way, I have also seen this issue with some of the Nissan/Tohatsu oil injected 2 strokes. I guess the plastic tank necks can get easily distorted for one reason or another and then they can leak. I resolved a few leaking issues by putting a hose clamp around the neck and tightening after the cap is installed. It works, but is a cheesy fix in my opinion. Don't really know why Merc didn't try harder to fix the problem. Their small reserve tanks on their larger V-6 engines don't have any issues that I have run into. (and they are plastic tanks with screw on caps with flimsy gaskets, yet they don't leak.
Don SSDD	posted 07-10-2014 07:15 AM ET (US) They could just use a regular screw on cap like the gas cans have, if a gas can lid can take the air pressure generated from a tank sitting in the sun, it should work fine on the oil reservoir. My 90HP has leaked from the lid for a long time. I "fixed" it using 2 o rings, works good unless you don't tighten it just right. You have to loosen it and re-tighten until you get it to stop leaking. I am going to try one of these flexible pipe caps, looks like it should work. Don