Smoky new Tohatsu M50

[rajabatis]

Hi, I have a fairly new Tohatsu M50 autolube motor. The motor has now gone through its break in period where it has been run on the automix plus a 50-1 oil ratio in the fuel as specified in the manual. The motor exhaust though when on that mix was very smoky. Running on straight gas it is still smoky.

My old 92 Evinrude 50 which this is replacing was never this smoky on just a regular 50-1 oil/gas mix.
Is there an adjusment I can make to the amount of oil the pump is putting out, or can I disable this and run the motor on a 50-1 gas/oil ratio without problem?

Thanks in advance. Your comments would be welcome.

 

[TOHATSU GURU]

Re: Smoky new Tohatsu M50

The oil pump can be adjusted, but it is unlikely that you need to. Disabling the auto-mix would be a disaster in the making. The problem is that you have had too much oil in the gas. Just endure and it will eventually run clean. But, first change the plugs.

 

[rajabatis]

Re: Smoky new Tohatsu M50

The oil pump can be adjusted, but it is unlikely that you need to. Disabling the auto-mix would be a disaster in the making. The problem is that you have had too much oil in the gas. Just endure and it will eventually run clean. But, first change the plugs.

Hi Elvin,
Thanks for the reply. I have ran a couple of tanks full of oil free gas ( using that name for fuel makes me smile as we call it petrol over here) through it and it is just as smoky as the run in period? Is it oil pooling in the crank cases? And it just needs more running to clear it?

I trailer the boat and when I get it in the water If i don't get moving quickly to get a flow of air going past me to clear the air it is unpleasent.

I don't use it for any slow running like trolling. Mostly it will be up in the 4750-5000 rev band. I have looked at the plugs and they are black and slightly oily. The bottom two more than the top one. I will change them though.

So you are saying this motor will not lube the main and con rod bearings properly if the autolube is disabled and run on pre-mix?

I'm interested in getting to know this motor. Can you explain how that pump works? I see that it is connected to the throttle linkage. What is the setup that draws the oil in to the motor?

Sorry for all the questions!


Thanks,
R.

 

[TOHATSU GURU]

Re: Smoky new Tohatsu M50

I'm saying that there is no sane reason to disconnect it. If the system has a fault you find the fault and fix it.

 

[rajabatis]

Re: Smoky new Tohatsu M50

I kind of thought that's what the questions were for - getting some advice on fixing it?

You commented it that it would be a disaster in the making if I disable the pump. How is that?

The fuel is drawn to the fuel pump and then to the check valve where the oil and gas mix. It then just goes straight into the carb and then the oil/gas mix is drawn in to the engine
as normal.
So why if that oil system was bypassed would it cause problems running the engine on pre-mixed fuel? No neat oil is pumped in to bearings at any point. The engine is effectively running as a regular pre-mix engine.

Anyway for anyone else that has a smoky Totatsu check your oil pump aligning marks. My one was out of sync and putting out too much oil and causing it to be excessively smoky.

It is a simple job to pop off the linkage and adjust the length of the rod to line up those marks and get it back to what should be the correct setting for the oil delivery.

Thanks for the input anyway. Have a nice one.

R.

 

[TOHATSU GURU]

Re: Smoky new Tohatsu M50

"The oil pump can be adjusted"

Literally the first thing I said...

I offer tips and guidance. I do not tell people how to fix outboards. In this case my lack of helpfulness is based on it being "a fairly new" engine. To me that means that a dealer should be the one screwing it up rather than the owner screwing it up, because it would be under warranty. Never, ever do anything yourself to an engine when it is under warranty. It's for your own benefit.

Now I'm sure you lined up the marks perfectly...Unfortunately that's only part of the process. Now you need to run the engine on a supply of premix while you have the oil line disconnected and have the oil running into a graduated cylinder so that you can actually measure the oil flow rate...See how it suddenly got complicated? As to why only no one would disconnect the system:

1) It would nullify the warranty.

2) It would increase oil usage.

3) It would foul out spark plugs.

4) It would decrease performance.

5) And this is the important one, your wife and children will laugh at you for buying a new engine and then disconnecting a system that is virtually flawless.

 

[rajabatis]

Re: Smoky new Tohatsu M50

Hi Elvin,

You offer guidence and not fix it advice? Gee that's just semantics and a very fine dividing line!

But in my original post I did say I had ran a few neat tanks of petrol through it and that it was still smoky. Quote: " Hi Elvin, Thanks for the reply. I have ran a couple of tanks full of oil free gas through it."
So much as I appreciate the input, your guidence comment was "endure it" which was not a lot of useful guidence. A "try this or that" might have helped?

Warranty is not an issue with me and it is none too easy to obtain service in any event in my remote area. This motor was a ridiculously inexpensive purchase. I'm happy to void the warranty by doing my own servicing.

"Now I'm sure you lined up the marks perfectly..."Unfortunately that's only part of the process. Now you need to run the engine on a supply of premix while you have the oil line disconnected and have the oil running into a graduated cylinder so that you can actually measure the oil flow rate...See how it suddenly got complicated? As to why only no one would disconnect the system??:"

The manual makes no mention of that measurment being necessary though?

That measuring process is hardly rocket science though is it? I have used flow cups to measure viscosity of liquids at various temperatures in my work place quite a number of times. So that holds no fears if that needs to be done. I can set it back to the original setting to get a volume figure to work from.

Would parts 2, 3 and 4 of your reply be the case? I'm not convinced.

On part 2. You may indeed be correct, but it strikes me this so called perfect system is far from that.......I think it fulfills a need that manufacturers have met for boaters who can't be bothered to pre mix. I know a system can be set up correctly and more accurately on a guranteed accurate oil/fuel mix which autolube does not deliver. The system is a comprimise.

Part 3. I may have been lucky but I have never had a fouled plug problem on an outboard motor set up properly that I have owned.

Part 4. We will have to agree to dissagree on that one. But more or less the same engine is available here and other countries as a commercial workhorse without the autolube and runs on a std pre-mix fuel supply. They don't seem to have plug fouling issues.......

Part 5. Thanks for the family guidence sermon. Dads hobby is part of the family though and it won't be a concern for them to hear dad curse when things don't work out! I fix all the family cars when they are broke and keep them running smoothly when they are not. A couple of those are over 10 years old and used daily.

I'm a happy inveterate lifelong tinkerer.

Regards,
R.

 

[Expidia]

Re: Smoky new Tohatsu M50

Hey Elvin

Isn't this where you start banging your head against the wall

That'll teach ya!

 

[rajabatis]

Re: Smoky new Tohatsu M50

Hey Elvin

Isn't this where you start banging your head against the wall

That'll teach ya!

LOL I hope I didn't cause offence? I see you are fellow a 2 stroke exhaust sniffer. Amsoil eh? Never tried that one yet.


Regards,

R.

 

[TOHATSU GURU]

Re: Smoky new Tohatsu M50

Unfortunately, somtimes when you lead someone to the water they don't drink it...They just fall in and drown

 

[rajabatis]

Re: Smoky new Tohatsu M50

Lol Compulsory life vest over here when out on the sea!

Nice place Tampa. Visited it some years back when on a business trip to America. Caught a few nice Sheapshead from the St Peterburg pier and a some Snook and Ladyfish from the Mangroves near Gandy Bridge. Great fun!

Regards,
R.

 

[rodbolt]

Re: Smoky new Tohatsu M50

its just to easy to buy the correct service manual and perform the correct linkage adjustments.
its not uncommon to see the linkage not set correctly out of the box. its also why the dealership is required to perform a linkage adjustment check, however most dont.
its also not uncommon to see the oil pump shaft seal leak.
myself I like to do consumption tests as well as pump output tests. the output test is nice,the consumption test will confirm or eliminate pump seal leakage.

 

[rajabatis]

Re: Smoky new Tohatsu M50

its just to easy to buy the correct service manual and perform the correct linkage adjustments.
its not uncommon to see the linkage not set correctly out of the box. its also why the dealership is required to perform a linkage adjustment check, however most dont.
its also not uncommon to see the oil pump shaft seal leak.
myself I like to do consumption tests as well as pump output tests. the output test is nice,the consumption test will confirm or eliminate pump seal leakage.

That's exactly what I did, refer to the manual.
How many hours on that leak thing? Are you talking about an external visible leak? There is no indication of a leak on the outside of that pump. This motor has only 15-20 hours on it.
Do you rig up a seperate smaller oil tank to get an accurate consumption figure? That seems to be the way to go.

 

[TOHATSU GURU]

Re: Smoky new Tohatsu M50

A quick word on the Tohatsu manual. It's a guide for a Tohatsu tech who has been to school, not a consumer manual that has 11 steps for a 10 step process

 

[rajabatis]

Re: Smoky new Tohatsu M50

Well I assumed that what Tohatsu were saying in the manual about setting the pump was accurate and set it as directed by lining up the scribe marks, I emptied out the oil tank and flushed out the pump and oil tubes of the old oil and bled the pump out, and took the plunge and got hold of some Amsoil synthetic Saber outboard HP injector. Put some 100-1 Amsoil premix oil in the fuel to be on the safe side fitted a new set of plugs and gave the carbs a going over with the vacuam gauge to make sure they were all sucking in the mix as they should. Bottom two carbs were running very slight rich and these were brought in to line. Then having done that gave the motor a good workout.
Result! I ran a tank through of premix and now it is running on straight petrol and is even sweeter.
I now have a very nicely running considerable less smoky motor now. No deposits on the plugs as was evident with my previous 2 stroke Shell outboard oil. My 60 HP Yamaha is running happily on the Amsoil synthetic too.


R.

 

[SgtMaj]

Re: Smoky new Tohatsu M50

EDIT: Nevermind, I see you posted while I was writing and you got it working. Congrats on getting it fixed up.

SgtMaj

 

[rajabatis]

Re: Smoky new Tohatsu M50

Hi Sorry about that! What were you going to add?
R.