White Gear oil. Tohatsu 4hp

[SignmanTN]

I was changing the gear oil in my new (June 2012) Tohatsu 4 stroke 4HP motor. I found that the vent screw was very loose, only two or three threads held it in. I was lucky it didn't fall out last time I had it in the water on Saturday.

So, I pull the fill screw and out flows white oil, not chalky, a very uniform white color, maybe slightly grey. Drained the lower unit well, no water came out, just the white oil.

I flushed it twice with motor oil to get rid of the white oil. Each time less and less white oil ran out with new motor oil. I left it filled with motor oil to keep any remaining moisture from harming the inside of the lower unit while I went to work today.

My plan is to keep flushing with motor oil until it runs totally clear, then flush it once with gear oil, then fill it with gear oil.

So my question is,, how would you go about flushing the lower unit more effectively than just running a couple of quarts of motor oil thru it? And how to keep these screws from backing out in the future? Can you use loctite on them?

I saw on-line everything from marvel mystery oil to a 50/50 mix of gasoline and oil.

I do have a shop manual, it doesn't seem to list procedures for this kind of problem that I can see.

Also, because this is part of my winterizing the motor, what are some good winterizing steps to take for a motor like this? Can someone point me to a winterizing checklist?

Thanks
Mike

 

[JB]

Re: White Gear oil. Tohatsu 4hp

Hi, Signman.

Welcome to iboats.

When flushing it, run the engine briefly (in a tank) to get the best mix of flushing oil and old oil. For very short periods, kerosene makes a good mixer.

The key to your problem is almost certainly incorrect seating of the drain/fill and/or vent plugs (not screws, plugs). They must have fresh crush gaskets (not washers) every time they are removed. Same if it uses "O" rings instead of gaskets.

 

[SignmanTN]

Re: White Gear oil. Tohatsu 4hp

quote
The key to your problem is almost certainly incorrect seating of the drain/fill and/or vent plugs (not screws, plugs). They must have fresh crush gaskets (not washers) every time they are removed. Same if it uses "O" rings instead of gaskets.
end quote


I agree that the water had to have come in thru the vent plug that was about to fall out.

This is the first time I have changed the gear oil. The gaskets on both of the plugs are flat black and kind of rubbery. From working on an old Fiat X1/9, most crush gaskets that I remember have a metal ring built into them that crushes, these aren't anything like that.

Here is a picture of them.



So, flushing with a mix of kerosene and motor oil, while briefly running the motor in a tank to mix the old oil with the flush mixture. Repeat until the flush mixture runs clear and clean.

Reflush with gear oil and then refill with gear oil.

What about the gaskets? Where these the wrong gaskets? And how do I keep them from backing out in the future?

Signman

 

[robert graham]

Re: White Gear oil. Tohatsu 4hp

Flush lower unit a few times with oil/kerosene/whatever, refill with Marine Lower Unit Oil, with a screwdriver blade that fits snuggly into slot on drain plug tighten good and tight with new specified washer...it'll stay tight like that...Loctite not so good come removal time!

 

[pvanv]

Re: White Gear oil. Tohatsu 4hp

I was changing the gear oil in my new (June 2012) Tohatsu 4 stroke 4HP motor. I found that the vent screw was very loose, only two or three threads held it in. I was lucky it didn't fall out last time I had it in the water on Saturday.

So, I pull the fill screw and out flows white oil, not chalky, a very uniform white color, maybe slightly grey. Drained the lower unit well, no water came out, just the white oil.

I flushed it twice with motor oil to get rid of the white oil. Each time less and less white oil ran out with new motor oil. I left it filled with motor oil to keep any remaining moisture from harming the inside of the lower unit while I went to work today.

My plan is to keep flushing with motor oil until it runs totally clear, then flush it once with gear oil, then fill it with gear oil.

So my question is,, how would you go about flushing the lower unit more effectively than just running a couple of quarts of motor oil thru it? And how to keep these screws from backing out in the future? Can you use loctite on them?

I saw on-line everything from marvel mystery oil to a 50/50 mix of gasoline and oil.

I do have a shop manual, it doesn't seem to list procedures for this kind of problem that I can see.

Also, because this is part of my winterizing the motor, what are some good winterizing steps to take for a motor like this? Can someone point me to a winterizing checklist?

Thanks
Mike

The new gasket you need is 332600060M GASKET $0.61. It's a fiber composition, no metal ring involved. They come 10 to a pack, but most dealers (including me) will sell them individually. If you need a replacement plug, order 332600052M OIL PLUG $4.67. The Factory service manual is 003-21034-2, (MSRP): $40.00.

Once you think you have all the emulsified white stuff out, be sure to refill the gearcase, and run it for a few minutes to splash the lube around, then drain to confirm it's all cleaned out.

Full winterizing procedures are at Tohatsu Outboards: Winterize Outboard Motor Tips

HTH.

 

[SignmanTN]

Re: White Gear oil. Tohatsu 4hp

Thanks for all of the advice everyone.

I have lurked on this forum since I got the motor and have appreciated how helpful everyone seems to be.

Based upon some of the threads in this forum, I have swapped out my 4HP carb for the 6HP carb and it made a pretty good difference in speed on my square back canoe. (11mph up to 14.2 mph)

Keep up the good work and thanks again.

Signman

 

[robert graham]

Re: White Gear oil. Tohatsu 4hp

One other item to check: remove prop and look for possible monofilament fishing line wrapped around prop shaft and worked it's way under that prop shaft seal causing leak and/or seal damage....take a close look at that seal and the surface of the prop shaft where seal contacts it. A slightly bent prop shaft on the smaller outboards can cause a small wobble, seal wear and/or seal leak...Good Luck!

 

[SignmanTN]

Re: White Gear oil. Tohatsu 4hp

Checked prop shaft and seals. No monofilament line and the seals look good. Shaft is within .001 using a craftsman dial indicator tool. I flushed and cleaned as per recommendations and that seems to have done it.

Thanks all
Signman

 

[Sea Rider]

Re: White Gear oil. Tohatsu 4hp

Next time, once new flushing oil leftovers has supposedly drained out, insert a low air presure hose to upper oil port while spinning prop to get the last drop out, if compressed air is not available, use mouth and hose...

Happy Boating