Tohatsu MW-50 HP 2 strokes

[Sea Rider]

Hi all,

Was wondering why the third lower carb has a 135 main jet when upper and middle carbs has 132 main jets, is it the fact that lower carb has the gas pump attached to it and my loose pressure or whatever tech issue to justify a slight bigger size jet ? Tohatsu 40 HP, 3 cylinder model has all 3 main jets, same size, including gas pump on lower carb. Any ideas, comments are welcomed.

Is the MW-50 late model a autolube mixing or a pre mix model ? Does the UL model comes with remote control box included inside box ?

Happy Boating

 

[TOHATSU GURU]

Re: Tohatsu MW-50 HP 2 strokes

That model engine is not sold in the U.S nor is the parts book even available to us. You will need to cotact the Tohatsu distributer in your own country for details.

 

[Sea Rider]

Re: Tohatsu MW-50 HP 2 strokes

Hola TG,

What about the standard D50 HP 2 strokes engine, the only difference with MW is that has taller crome plated water pump & impeller, heavy duty thermostat and wider anticav plate, carb issue is the same for both models.

Happy Boating

 

[TOHATSU GURU]

Re: Tohatsu MW-50 HP 2 strokes

You would still have to direct that question to Tohatsu. I've never questioned why as I never thought it was important since they made that change when they stopped importing the D2 into the U.S. The D2 used the same jet up until they did the last revision in mid 03. Since the U.S. EPA regs prohibited that model from being imported here I haven't kept up with the changes that are made to it. If you like I can send an email to Japan asking why...But, you can do it yourself just as easily.

 

[Sea Rider]

Re: Tohatsu MW-50 HP 2 strokes

Hello again,

It's not that I'm really interested on the subject, have 10 UL engines to offer for commercial/fishing needs, have spotted in other forum strange comments & issues like:

*The bigger lower jet is for cooling better the lower cylinder as is receiving last, pumped water through water passages.
* The lower bearing needs more oil to lubricate better end crankshaft.
*Some recommends to change lower jet for 132 main jet so to have same size jets in all cylinders.

Needed a tech answer as to stop nonsense speculations. Thanks anyway.

Happy Boating

 

[TOHATSU GURU]

Re: Tohatsu MW-50 HP 2 strokes

I'll pop an email out to Japan on Monday. The cooling thing is untrue, the oiling thing sounds like it could be plausable, but I personally doubt it and the change the jet thing wouldn't be a good idea...Tohatsu must have a reason for it Now I kind of want to know for myself

 

[Sea Rider]

Re: Tohatsu MW-50 HP 2 strokes

Hola TG

Some cat racers that uses Tohatsu 2 strokes 50 models change lower jet, so to have all 3 same size, they even don't know, there is too much speculation talk on cons and pros, definitely will be cool to have the right tech answer from the manufacturer, thanks!

Happy Boating

 

[TOHATSU GURU]

Re: Tohatsu MW-50 HP 2 strokes

Tohatsu Japan said that it allowed the engine to meet an EPA emission level that they needed and that it improved hesitation. I haven't run one of those in comparison trial to an older one so I can't speak to any noticeable difference in throttle response.

 

[Sea Rider]

Re: Tohatsu MW-50 HP 2 strokes

Tohatsu Japan said that it allowed the engine to meet an EPA emission level that they needed and that it improved hesitation. I haven't run one of those in comparison trial to an older one so I can't speak to any noticeable difference in throttle response.

Seems a fair environmental tech answer, by hesitation, are you talking about third lower carb hesitation, a pulse issue, as the gas pump is connected to this carb ?

 

[TOHATSU GURU]

Re: Tohatsu MW-50 HP 2 strokes

Since the 50D2 didn't have any hesitation I have no idea what they thought they were "improving". "Improved" might be a translation error of some kind or perhaps they made some other change on the D2 that required a change in that jet to keep it from having a hesitation. As a WAG I would say it was 99.99% EPA related and .01% performance...But, that's just a guess. I wish we could still get those models as the weight/performance/value was outstanding. You don't know how lucky you are to not be living under the thumb of the Evironmental Gestapo The idiots are trying to make our fuel 15% alcohol here. That is going to be an issue as the cylinder walls are going to become prone to drying out on 2-strokes.

 

[Sea Rider]

Re: Tohatsu MW-50 HP 2 strokes

Since the 50D2 didn't have any hesitation I have no idea what they thought they were "improving". "Improved" might be a translation error of some kind or perhaps they made some other change on the D2 that required a change in that jet to keep it from having a hesitation. As a WAG I would say it was 99.99% EPA related and .01% performance...But, that's just a guess. I wish we could still get those models as the weight/performance/value was outstanding. You don't know how lucky you are to not be living under the thumb of the Evironmental Gestapo The idiots are trying to make our fuel 15% alcohol here. That is going to be an issue as the cylinder walls are going to become prone to drying out on 2-strokes.

Thanks TG, really appreciated, wise words, very lucky to still count with 2 stroke old technology available down here, slow entering EFI 2T models as nobody likes heavier 4 strokes, will have lot's of problems with alcohol use in gasoline as in Brasil, thought that 10% was the max.

Happy Boating