Yamaha '04 90hp 2 stroke oil tank leak from low level indicator cap?

[rodbolt17]

I realize folks are thread hopping.
to many ********g oil tanks that about all they have in common is they hold oil.
leads to a lot of confusion.
under NO circumstances, LET ME REPEAT, under NO circumstances do any have silly-cone anywhere NEAR the oil sytem, this will include tanks and lines.
best marine use of silly-cones is using it to throw at annoying folks on the dock.
there are very few specified uses for silly-cone in a marine application.
however over the years the mis-application has made me a lot of money.

as has backyard engineeers with oiling solutions.
kinda like when I replace pistons due to water pump failures, I ALWAYS break down the cost to isolate the cost of the pump and labor to replace it seperately from the powerhead repairs.
Funny thing it cost the same with or without the powerhead repairs.

kinda like folks that trust the alarm system rather than a proper repair of said systems.

I typically seperate that cost as well.

oil system failures,including lack of oil, are typically catastrophic and half the time the cost of a rebuild is prohibitive.

[throrope]

Good to hear from you rodbolt.

Well, finally found my leak and sure enough, it's the oil gauge assembly. Got bad enough. to to I agree, crappy design. Now where to find a solution for less than. Than 100 bucks.

[ctbeacher]

Work around

As I mentioned in an earlier post, the only way not to lose oil is to lower the motor to the running position, and fill the reservoir to just up to the level of the oil sending sensor before leaving the dock. I can run for a few hours without using too much oil.

That works for me, but you should monitor how much oil you use per hour. Fill it to the sensor, run for an hour and refill to see how much you used. Try running an hour at both high and low speeds (low speed might use more per hour).

I have no problem in usage for a 1/2 day or so on the water, but in case, I keep a 1/2 gallon of oil on the boat as an emergency supply.

As someone mentioned before, no one should trust the alarm - know your motor and be diligent about checking levels before, during and after your cruising.

Whoever engineered this should be ashamed. It was destined to fail.

[bhadfield]

Oil Sending Unit Leak

I just found this same leak from the oil sending unit on my '06 90hp after taking the boat out of winter storage. So my thought is forget tie-wraps and replacement of oil sending units, I want to fix this thing permanent with an external oil tank like on the bigger outboards. I don't like the thought of replacing bad parts with more bad parts.

Could anyone point me to an external tank solution? I know it will probably take a tank/pump of some sort and wiring but isn't that a better way to solve this for good? I'm going to start looking for an after-market answer.

Any help is much appreciated,

Brad

[FabricGATOR]

A friend deleted the tank system and just mixes 50:1 like the old johnnyrude days.

[Hawk90yamaha]

So far so good

I had the same oil leak at the rubber oil level cap. I read all the threads and used the tie wrap method whick at least slowed the leak. I tried a new approach which is working as of this writing. I noticed a notch on the outside of the rubber cap. I placed an o-ring in that notch and then placed a hose clamp over it. I also put heat shrink on the hose clamp to prevent any damage to the clamp. I was also careful not to interfer with the wires.
Note: I pumped the oil out of the tank before attempting the repair. Now that I found that it works the o-ring can be fitted without removing the cap and level unit by simply disconnecting the wires to the cap and threading the o-ring over the top. I hope that is helpful for anyone experiencing the same issue.

[yamahasky]

I just went through this repair. I got tired of the oil puddles in my driveway and garage and took it to my local Yamaha dealer. My 90hp is a 1993 so not sure the same design applies to your later model but the mechanic told me that when these units start to get old they actually start leaking out of the wires. That is why it is so hard to fix and better just to replace the unit. Yes it cost me $150 plus, but at least now I have no more oil spots in my driveway and garage and can keep a full oil tank.
Best,
tom

[bhadfield]

My bass fishing buddy in Chattanooga who has a 225 Merc with an external tank mentioned that it just feeds the on-engine tank so I guess I'm headed for part replacement. In Wisconsin, I can't help but wonder that the tank itself may be cracked due to cold as I store it unheated. The tank itself, looks pretty cheap so I'll probably replace it and the sending unit since I'm in there and then wait a few more years to do it all over again.

Thanks for the comments,

Brad

[throrope]

Another post referenced using pipe thread tape. I took their lead and picked up a roll rated for fuel and oil at sears hardware. Upon pulling the level alarm, I found the oil seal is not at the cap, but rather a ring around the alarm "shaft" part way down. I simply wrapped the seal ring with the thread tape and forced it back down. No ties or clamps. After the accumulated puddles found their way out, no more drips. So far so good and not bad for 99 cents. When I find the pics I took, I'll be back to post.

[86whaler]

I have a 2001 90 and am having the same issue. I've gone down the same path as many of you here, wireties etc... Nothing has worked so far. I'll try the thread tape next, if that fails, I'll do the replacement. I'm tired of the oil puddles in my garage.

[Gungnir!]

Leaking oil tank cap driving me insane

Another post referenced using pipe thread tape. I took their lead and picked up a roll rated for fuel and oil at sears hardware. Upon pulling the level alarm, I found the oil seal is not at the cap, but rather a ring around the alarm "shaft" part way down. I simply wrapped the seal ring with the thread tape and forced it back down. No ties or clamps. After the accumulated puddles found their way out, no more drips. So far so good and not bad for 99 cents. When I find the pics I took, I'll be back to post.

Pictures?

Frankly, this issue is driving me nuts. I tried wrapping the cap with silicone tape, that did nothing. Then I got a very narrow tie-wrap that fit under the protruding "key". I thought it worked. A few days later, there was oil in the splash wells, not much from the port engine, but still leakage.

This is a big problem for me as I keep my boat in the water (salt) and it is important to me to keep the engines up and out when berthed. What an aggravation.

[boscoe99]

Pictures?

Frankly, this issue is driving me nuts. I tried wrapping the cap with silicone tape, that did nothing. Then I got a very narrow tie-wrap that fit under the protruding "key". I thought it worked. A few days later, there was oil in the splash wells, not much from the port engine, but still leakage.

This is a big problem for me as I keep my boat in the water (salt) and it is important to me to keep the engines up and out when berthed. What an aggravation.

Why not change out the sensor?

[throrope]

Pictures?

Frankly, this issue is driving me nuts. I tried wrapping the cap with silicone tape, that did nothing. Then I got a very narrow tie-wrap that fit under the protruding "key". I thought it worked. A few days later, there was oil in the splash wells, not much from the port engine, but still leakage.

This is a big problem for me as I keep my boat in the water (salt) and it is important to me to keep the engines up and out when berthed. What an aggravation.

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DSCI0039.jpg

Here ya go and it did the job! The other ugly is heating expands the air inside the tank forcing the oil up the gap around the alarm and past the failed seal and then cooling contracts to pull in air for the next round. With the seal secured, the pressure will take path of least resistance and "burp" the rubber tank cap instead.

Good luck and keep us posted.

[throrope]

Why not change out the sensor?

See part No. 51 $. 2004 90TLRC Yamaha Outboard OIL PUMP Diagram and Parts

[throrope]

update

Now a year later and all is well.

I doubt I'll be posting much moving forward. I found the solution to all my outboard needs. Anyone who frequents the OBX can share my success by asking for Tom at Joe's marine service In Wanchese.

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Here ya go and it did the job! The other ugly is heating expands the air inside the tank forcing the oil up the gap around the alarm and past the failed seal and then cooling contracts to pull in air for the next round. With the seal secured, the pressure will take path of least resistance and "burp" the rubber tank cap instead.

Good luck and keep us posted.