Oil tank is coming off

[clop52]

Had the boat out today after redoing the carb and changing the pulser coil.  She was riding good and the engine was firing great, until the dreaded overheating alarm starting going off.  I slowed down, checked to make sure there was enough oil in both tanks (external and the one in the motor) and they were fine.  So i guess it's either my oil pump or something else. SO, i am considering taking the entire oil injection system out and just mixing the oil in with the fuel.  I have done some initial research and it seems pretty common.  I also found the "best" oil out there, OPTI-2. My father-in-law sears by it. Anyone has done this before?
Thanks!
I have a 1993 115 Yamaha 2 stroke.

[Capt. Bob]

Well I'm an oil injection guy so my opinion is bias.
That stated, I would troubleshoot and repair the system, rather than remove it. The Yamaha system is known for reliability and on my 92, it smokes very little.

If you have a factory service manual, it should have the TS procedures you can follow. I've cut and pasted one I found online below.

As far as what oil to use if you go premix, well the cheapest TC-W3 oil would be my choice. I know nothing of Opti-2 but.....

First, cause I'm cheap but second is that today's oils are most likely a high quality than what the OEM manufacturer spec'd and it only has to lube the motor once then it is expelled into the atmosphere. The newer outboards spec a higher grade and one would be wise to follow their lead  but why would you burn stuff that cost more and in some cases much more? Now if you find it at a great price sure but again......

Here's a primer on Yamaha's system. I have a more comprehensive one in my manuals at home. I'll see if I can get it up on the site. There's one hidden somewhere here but I can't seem to locate it.

Good luck with either direction you take.

Yamaha's system consists of two lubricant reservoirs, an electric pump, a crankshaft-driven metering pump, float-activated switches, filter screens, hoses and an electronic oil-control system. A 2.7-gallon reservoir (actually, a remote tank) mounted inside the boat contains the electric pump, filter and a fluid-level sensor switch. An oil hose from the remote tank attaches to the engine-mounted main tank, and a wiring harness connects it to the outboard's electronic circuitry. The main tank also contains a filter screen, float and three switches that send information to the oil-control unit. Two-stroke oil is fed via gravity through a hose on the bottom of the main tank to the crankshaft-driven oil pump, where it is metered to the engine.

LUBRICANT TRANSFER

All decisions about transferring oil (as well as sounding any alarms) are made by the electronic oil-control unit. On V-4 and older V-6 outboards, it consists of an external black box with a momentary toggle switch. In later V-6 models, Yamaha incorporated the switch and electronics into the CDI unit.

Located in the boat, the remote tank holds oil that is pumped to the powerhead as the engine demands. Mounted in a recess on the side of the tank, the electric oil pump receives the lubricant through a filter element and transfers it to the main tank, which is located on the powerhead. A float activates a switch (SW B) inside the reservoir when approximately 1-1/2 quarts remain. The switch signals the oil-controller to turn on the yellow warning LCD on the tachometer, and to stop the transfer of oil to the outboards main tank.
Inside the main tank, three float-activated switches inform the control unit when the tank is full, when to transfer more oil, and when to sound the alarm if the level drops too low.

As long as the remote tank contains enough oil, a green LCD lights up on the tachometer and the electric pump will transfer oil to the engine as needed. In the main tank, as oil is consumed and the level drops, a float triggers the middle switch (SW 2), which informs the control unit to turn on the electric transfer pump. The additional oil allows the float to rise up and initiate the upper switch (SW 1) to shut off the pump. In the event no lubricant is transferred and the oil level decreases enough for the float to pass the bottom switch (SW 3), the oil-control unit sounds a warning alarm, the red \"no oil\" LCD lights up, and the outboard slows to around 2000 rpm for its protection. This warning alerts the skipper that only one-third of a quart remains in the main tank.

MANUAL OVERRIDE

As long as theres sufficient oil in the remote tank, it can be manually transferred to the main reservoir by pressing the momentary switch to bypass the oil-control unit. The toggle switch turns the pump on for as long as it is held in position; the upper float switch (SW 1) will not turn it off. This allows you to refill the main tank and continue with normal engine operation as long as the float remains above the lower switch (SW 3).

When additional oil is added to the boats remote tank, the float rises above SW B, which allows the controller to turn off the yellow warning LCD. If the outboard is running, the electric pump begins to transfer oil to the engine until the main tanks full switch (SW 1) shuts it off.
Depending on your outboards model year, various methods are used to prevent oil from transferring when the outboard is tilted up. On models with a separate oil-control module, an internal mercury switch will not allow the electric pump to energize if the outboard is tilted above 30 degrees. The trim sender senses the tilt angle to prevent the oil transfer on V-6s from 1990 through 1995. Starting in 1996, new electronics in the controller unit keep the pump from operating if the engine is not running. Do not forget to check these items when troubleshooting a \"no oil transfer\" situation.

SYMPTOMS TO WATCH FOR

Common symptoms of trouble include a lack of oil transfer, overfilling of the main tank, and oil leaks while the outboard is tilted. Most of the time, these problems are due to operator error and are not the components fault.

Non-transfer of oil to the engine-mounted main tank can be as simple a problem as a neglected filter. Moisture gets into the remote tank from spray, rain, condensation, or from being located in the bilge where it can be splashed or submerged. The water forms a sticky emulsion in the bottom of the tank and plugs up the fine screen in the filter element.

An overflowing main tank sometimes results from someone twisting or incorrectly installing the rubber cap on the float assembly and screen element. The tubular screen has an offset nipple that fits into the bottom oil-outlet going to the metering pump, and can bind the float if moved out of place. The arrow marks on the cap and tank should be aligned.

Leaving the key on by mistake can also cause overflow problems. As the battery run drops below 9.5 volts, the oil-controller electronics go off line, and a ground path is formed which starts the electric pump turning very slowly. Eventually, the main oil tank overfills and spews excess oil out a vent tube into the air silencer box.

While the outboard is tilted, a leaking rubber cap on the main tank can result from improper assembly or from twisting out of place. A plastic tie-wrap snugged around the rubber lip usually cures the leak. The clear sight tube on the bottom of the tank can become brittle with age, and oil may seep between it and the nipple. Replace the tube if it feels stiff, and secure it with a tie-wrap.

TROUBLESHOOTING TIPS

Since the electric oil pump and each switch have voltage going to them at all times, troubleshooting is fairly simple. The electric pump turns on when the ground circuit is complete, and each switch (when activated) completes a circuit. The oil-controller cannot be tested, though and can be considered faulty only through a process of elimination.

When no oil transfer occurs, lift the toggle bypass switch to see if the pump runs and starts to fill the main tank. If it does, either the tank's float assembly is inoperative or the oil-controller is faulty. To check the float assembly, disconnect its wiring plug and ground out the brown (on early engines) or the blue-green wire on the wiring harness side. If the pump and wiring are in good condition, the pump should stay on. Grounding the white (on early engines) or blue-white wire will turn the pump off.

In cases where the pump does not operate or runs without delivering oil, remove the boats remote tank and inspect for corrosion, bad wiring or a plugged filter. You can test the pump by using jumper wires to put 12 volts directly to it. The brown wire is positive and the blue is negative.
Overflowing can result from several factors. If the pump continues to run and the oil level rises above the upper line on the tank, disconnect the wiring and ground out the white (on early engines) or blue-white wire. The pump will stop unless the oil-controller module is bad or there is a grounded blue wire in the harness somewhere between the pump and controller.

TESTING THE FLOAT SWITCH

An ohmmeter can be used to check the switches inside the main tanks float assembly. Carefully remove the unit, making sure the black foam sealing washer stays with the tubular filter element. If it remains in the tank, the seal can be forced into the feed hose going to the engine-driven metering pump which could block the flow of oil.
Hook up the negative lead to the black ground wire, and the positive lead to each other wire in turn. When you move the float, the ohmmeter should show that each switch \"closes\" when the float passes by. If any switches are defective, the assembly must be replaced. Be sure to install a new foam sealing washer every time the assembly is reinstalled.

Follow the service manual procedure when testing the remote tank's float switch. It is normally closed, and opens when activated by the float. Early models have electronics inside the assembly and require different test methods than later models containing the circuitry in the oil-controller.
 

[wingtime]

I would leave the system on.  I think we are way past the days of not trusting oil injections systems.  They have been proven to be very reliable.  Are you sure the overheat is due to lack of oil?  have you check your T-stats? Poppit valve Recent water pump?

[Capt. Bob]

have you check your T-stats? Poppit valve Recent water pump?

I would agree. Overheating at speed sounds like a poppit (pressure relief) valve to me. Known issue on old Yamaha motors. They've been using an updated valve for years now.

[clop52]

Thanks for all the replies. I am not giving up on the oil injection system just yet.
First, Capt Bob. Thanks for all that info.  I just got done taking both oil tanks off to ensure cleanliness and clear connections.  I'm glad i did, there some water at the bottom of the external oil tank. Everything else looked good.  I am going to clean it all and put it back together tomorrow after work.
Wingtime, last year i had a similar problem and replace the water pump/impeller and it fixed it. That was my first instinct, but I was getting good pressure from the water being expelled from the impeller.
Poppit? i'll have to look that up and its location.  Are you saying that they updated that valve and didn't tell me? I'll check the t-stats as well. Thank you all, i'll post again tomorrow.

[boatnamesue]

...until the dreaded overheating alarm starting going off.  I slowed down, checked to make sure there was enough oil in both tanks (external and the one in the motor) and they were fine.

Please forgive me, I’m a little confused as to why you checked the oil tanks when you’re stating the overheat (high temp) alarm stated going off.  I’m led to believe the reason you checked the oil level after alarm activation is because you DO NOT have a yamaha tachometer.  Am I correct?  Because the tachometer gives you the visual indication for which of the 2 alarms is activated.  These 2 alarms are completely autonomous from one another, each having their own sensor. 

You've got 2 audible alarms for your engine, high temp and low oil.  Both alarms will also cause activation of rpm reduction mode, aka "limp mode", allowing engine to operate at no more than 2000 rpms.  The visual alarm indicators coinciding with these 2 alarms are located on the yamaha multifunction tachometer screen.  When 3 solid bars are located over the oil symbol (green), all is good.  1 solid bar on left of symbol and 1 blinking bar over the symbol (yellow), reserve tank low oil.  All 3 bars blinking (red-yellow-green), main tank low oil, limp mode activated.  1 blinking bar over and to left of symbol (red), reserve and main tank low oil, limp mode activated.  This covers all possible visual indicators for oil alarm. 

When high temp alarm is activated, the engine immediately goes into limp mode, the audible alarm activates, and a blinking bar can be seen over the high temp symbol on the tach gauge.

If you don't have a yamaha tachometer to indicate to you which alarm is activated, and both reserve and main oil tanks were full at the time of alarm, by process of elimination the high temp alarm is activating.  So before you go disassembling the oil injection system, you first need to determine which of the 2 alarms is activating.  Then determine the cause of alarm.  Even though both oil tanks were full at the time of alarm activation, the low oil alarm could be activating if the sensor is bad.  A faulty oil sensor is unlikely, but is possible.  Also, I couldn't agree more with wingtime.  Why remove the oil injection system when you don't even know if this alarm is being caused by the oil system.  And even if it is, fix the problem, don't remove the problem.  Just my opinion. 

Assuming the oil sensor is functioning correctly, and both tanks were full as you verified, then this leaves the high temp alarm.  By order of importance and most likely causes for this alarm are as followed:
1. Bad water pump
2. Bad thermostat(s)
3. Blockage in cooling system
4. Bad pressure control valve (PCV, aka poppet valve)

Wingtime, last year i had a similar problem and replace the water pump/impeller and it fixed it. That was my first instinct, but I was getting good pressure from the water being expelled from the impeller.

Don't let the strength of the tell tale (pisser) fool you.  Just because the engine is pissing like a race horse does not imply water is being circulated through the cooling system.  Also, it's very possible the cooling passages have become filled with corrosion to the point of causing the engine to overheat.  This scenario becomes more possible if your engine is operated in saltwater, and if you or the previous owner have never pulled off the heads to clean the water passages.  It's a 24 year old engine, so it's very possible cooling system corrosion is causing overheating.  The pressure control valve is the unlikely culprit, but worth checking if the pump and stats are good.  Below is the parts blow out of your crankcase.  I've circled in red the location of the PCV.

[clop52]

You are correct. I do have a tachometer and the overheating alarm was going off, not the low oil alarm. These are the steps I took that led me to believe that the problem was in the oil system:
-As soon as the alarm started going off, the engine didn't automatically bug down, I manually slowed it down to less than 1000 rpm before the alarm would shut off.
-I checked the pissing strength -which I know now not to trust- and it seemed ok.
-Removed the cowling and checked the oil on the tank and it was full.
-Touch the heads and were not too hot, just warm. That made me rule out water pump.
-My hyphothesis was that maybe the engine was not getting enough oil since the alarm would only sound off when I sped up too quickly and it wouldn't when I sped up incrementally, up a certain point. Once I reached 4000 rpm, the alarm would sound off.

Let me know if my hyphotesis is wrong.

What I'm going to do:

-Check Outter tank pump. 12 volt test. Reintall.
-Reinstall inner oil pump, bleed.
-Check poppet, clean and reattach.
-Check thermostats. (What do I look for on those?)

Thanks again for all your input, I'm getting a lot better at all these. Don't like buying new...too boring.

[clop52]

FYI, this what my tachometer looks like.

[Capt. Bob]

Is this what your multi gauge speedo/fuel/temp looks like?

That would be what would light up if you had an "overheat condition".

The little thermometer on the left, close to the bottom. These are old school Yamaha gauges (93 and earlier) They were updated in 94 (IIRC) but your tach looks original so I'd guess so is the speedo.



Is the temp icon indicating an overheat?

[clop52]

These are all my gauges. The speedometer does not have a overheating indicator.

[boatnamesue]

You are correct. I do have a tachometer and the overheating alarm was going off, not the low oil alarm. These are the steps I took that led me to believe that the problem was in the oil system:
-As soon as the alarm started going off, the engine didn't automatically bug down, I manually slowed it down to less than 1000 rpm before the alarm would shut off.
-I checked the pissing strength -which I know now not to trust- and it seemed ok.
-Removed the cowling and checked the oil on the tank and it was full.
-Touch the heads and were not too hot, just warm. That made me rule out water pump.
-My hyphothesis was that maybe the engine was not getting enough oil since the alarm would only sound off when I sped up too quickly and it wouldn't when I sped up incrementally, up a certain point. Once I reached 4000 rpm, the alarm would sound off.

Let me know if my hyphotesis is wrong.

What I'm going to do:

-Check Outter tank pump. 12 volt test. Reintall.
-Reinstall inner oil pump, bleed.
-Check poppet, clean and reattach.
-Check thermostats. (What do I look for on those?)

Thanks again for all your input, I'm getting a lot better at all these. Don't like buying new...too boring.

You have the old old style yam tach, which does not include the visual high temp alarm.  I believe that model of tach was paired with the yam speedometer that did have the temp symbol.  So in your case, if you're getting an alarm and no bars are flashing over the oil symbols it's safe to assume the alarm you hear is caused by high temp.  It's also possible the alarm you're hearing is due to low voltage, and this alarm would not cause limp mode.

I would go about troubleshooting by first testing both alarms to verify proper function, this will rule out the possibility of false-positive alarm activation.  Test oil alarm as followed:
*Drain main tank oil level to below the tank's bottom level line.  Turn key to ON position.  Alarm should immediately sound and you should see all 3 bars blinking over the 3 oil symbols on tach.  Refill main tank.
*Drain reserve tank.  Turn key to ON position.  Alarm should immediately sound and you should see 1 solid bar on left and 1 blinking bar over middle symbol on tach.  Refill reserve tank.
*If one or both of the above actions does not cause alarm, the oil sensor(s) is bad.

Test thermosensors as followed:
*Each engine bank has a thermosensor with 2 pigtail wires coming out of it.  Disconnect these 2 wires from the engine side wires, then connect together the 2 engine wires.  Turn key ON.  Alarm should immediately sound.  Repeat the same test on other bank. 
*Test each thermosensor by using the instructions in the below attachment.



Here is the procedure for checking function of stats:





If you've confirmed both oil and temp alarms to be functioning properly, now you can dig into the issue causing the alarm...which I recon to be high temp.  You described the alarm will sound when quickly throttling up, but will not alarm if you slowly increase throttle.  To me this sounds like there is an area within the cooling system within 1 or both banks that is blocked by corrosion.

Once you've checked stats, confirmed alarm function, etc., I suggest pulling the head covers off to inspect cooling system.  It's a simple and fairly quick procedure, so long as you don't snap a head bolt.  If you haven't removed the head bolts since owning engine, no telling how long it's been since these bolts have been backed out.  You probably will encounter a stuck bolt considering the engine age.  Just be very gentle when backing these bolts out.  If you're trying to back one out and it won't budge, stop.  Get some PB blaster or likewise and spray bolt.  Let it sit a minute, then try again.  If this doesn't work you can then resort to heat cycling the bolt.  This does the trick 99% of the time if done carefully.

Once the head covers and heads are off plan on replacing the gaskets.  Don't reuse the old ones unless you just recently replaced.  I'm reckoning you're gonna encounter a lot of passages with corrosion.  And that's when the real labor begins.  We'll touch on that if need be.

[RickK]

That's good stuff Jason!  Thanks for taking the time to post that.  We might grab it for the Resources forum.

[clop52]

Jason, thanks for the thorough explanation. I will follow those steps as soon as I can  and let you all know how it all turns out!

[boatnamesue]

That's good stuff Jason!  Thanks for taking the time to post that.  We might grab it for the Resources forum.

Jason, thanks for the thorough explanation. I will follow those steps as soon as I can  and let you all know how it all turns out!

Thanks, happy to help.

Btw, another diagnostic tool that could be helpful is to get a thermal temp gun.  Using the gun would immediately eliminate the possibility of alarm false-positives and simultaneously tell you which bank is overheating....if indeed overheating is the issue.  Worth the $30-$50 or so to keep in your tool box for times like these.  No need to buy the fancy $200 ones.  http://www.techtoolsupply.com/ProductDetails.asp?ProductCode=KLN-IR5&source=googleps&gdffi=a2fd11e1880844dfbe0b89871fd6ef5c&gdfms=B9B3F7B1751745D18C3788C991414CBF&gclid=EAIaIQobChMIn8jzytGy1gIVkmF-Ch1bzAAYEAQYFyABEgJvdPD_BwE

[clop52]

Cool tool. If i use that, is there a temperature that is normal operation for a head or would i just compare the two to see which one is hotter?