2 stroke 90 Yamaha Oil Reivor leakr

Leaking at the level switch. Just started this winter while it was stored. Read several thread posts on the internet but was also wondering in anyone here has repaired theirs. Any successful cheap solutions other than replacing the unit?

Does that unit just “plug” in to the opening of the reservoir?


"Apathy is the Glove into Which Evil Slips It's Hand", but really, who cares?

If I remember correctly, the pump in the reservoir tank isn’t shutting off and overfilling. It isn’t recognizing that the tank is full. I forget what I did to correct it though…Chris will tell you in when he sees your post. Search how the pump triggers…I think there is a float system on that pump(or was electrical).


The ENTER-NET Fisherman

Yes - best I can tell from the YouTube. haven’t pulled it out yet. Need to drain reservoir before I try as I store it full over the winter, but wanted to have a game plan before I dive into it. I have other planned maintenance so I’m waiting on parts and weekend day w/o rain.

Seems most threads out there see this as a sealing problem around the “plug”, both on the inside diameter and the outside diameter. The “fix” that seems to work as reported by a few was either modded O-rings for the ID or a couple wraps of teflon tape on the ID of the plug/assembly and a few wraps on the od of the reservoir itself. All internet threads seem to think this is a bad design and this leak is fairly common. Ty-wraps around the outside of the plug evidently do not work as reported by most.

hose clamp or Radius zip tie, will fix the problem.


www.teamcharlestonmarine.com IF I RESPOND IN ALL CAPS, ITS NOT ON PURPOSE, AND I AM NOT YELLING

Made a first attempt to stop the leak. I wrapped 3 wraps of Teflon tape around the OD of the resivor opening and 2 wraps of tape around the sending unit. To do this I had to drain the tank below the sending unit, drop the tank off (3 bolts) and the pull out the sending unit completely. Took all of 15 minutes. Will report back after a few days if this repair works.

Does this have a separate oil reservoir tank that you fill inside the boat? If not forget this post. The old 150s/250s did. Mine was pumping oil to the engine tank and didn’t recognize when to switch off. noticed oil coming out the cowl.


The ENTER-NET Fisherman

Here you go:

https://www.yamahaoutboardparts.com/forum/general-discussion/yamaha-outboard-forum/5200-yamaha-04-90hp-2-stroke-oil-tank-leak-from-low-level-indicator-cap/page3

Might help


The ENTER-NET Fisherman

Does this have a separate oil reservoir tank that you fill inside the boat? If not forget this post. The old 150s/250s did. Mine was pumping oil to the engine tank and didn’t recognize when to switch off. noticed oil coming out the cowl.


The ENTER-NET Fisherman [/quote]

mdaddy - This engine has the reservoir under the cowling - 3.5 quarts.

Thanks - yes, read this one too. Interestingly, the fix that I went with was from a thread in Australia. Its holding so far. Gonna give it a few more weeks before I claim victory.

Tenacity… I like it. Goes back to engineers designing something they don’t have to fix. They ought to make them do an internship at a repair shop.

Rant: The USA used to make engines that were simple and worked. Loose tolerances and few electrical parts. I miss those days.


The ENTER-NET Fisherman

I’m gonna claim victory on this. 1 week in, 3 trips over the weekend and the leak as not re-appeared.