Tohatsu 50D2 Timing

[Bobbyjoeufb]

I have a 2004 Tohatsu 50D2 hp on a Zapcat.

Last year I carried out a tune up following the Clymer Workshop Manual and afterwards the engine would rev high at tick over and had lost some of its top end speed. After adjusting the timing and throttle link rods I managed to regain some top end speed but the tick over is still high and idle screw makes no difference.

The timeing link is set at 98mm and throttle link is 115mm, can any one tell me if this is the correct settings or suggest what else I could try?

 

[comanr]

Re: Tohatsu 50D2 Timing

here is the information for you attached

EDIT: Publication of copyrighted material is not allowed, and a Federal Crime, also. JB

 

[Bobbyjoeufb]

Re: Tohatsu 50D2 Timing

Thanks ill try that out tomorrow.

 

[Bobbyjoeufb]

Re: Tohatsu 50D2 Timing

Still no joy!

can anyone tell me what is the correct timing mark on the crankcase as there seams to be three flat surfaces one left one middle where gasket and head meet and the 3rd on the right?

 

[TOHATSU GURU]

Re: Tohatsu 50D2 Timing

See page 2-27 of the serice manual for the correct procedure. You need to look at diagrams 9 and 11 to see the relationship between the mold boss and the set ring.

 

[Bobbyjoeufb]

Re: Tohatsu 50D2 Timing

Thanks but I think you must have a different manual as the page numbers dont cover the timing procedure.

The Clymer manual I have states "Align the flat surface of the crankcase mating surfaces with the calibration marks on the set ring." It gives two diagrams but these point to the left handside of the flat surface, however its not clear on the engine where this flat surface is.

Do you have a photograph or better diagram showing this flat surface?

 

[Bobbyjoeufb]

Re: Tohatsu 50D2 Timing

Thanks but I think you must have a different manual as the page numbers dont cover the timing procedure.

The Clymer manual I have states "Align the flat surface of the crankcase mating surfaces with the calibration marks on the set ring." It gives two diagrams but these point to the left handside of the flat surface, however its not clear on the engine where this flat surface is.

Do you have a photograph or better diagram showing this flat surface?

 

[TOHATSU GURU]

Re: Tohatsu 50D2 Timing

Unfortunately it is a violation of copyright to post that so I can't. You need to pick up a Tohatsu factory manual from a dealer in your area.

 

[Bobbyjoeufb]

Re: Tohatsu 50D2 Timing

Will see if I can get hold of the Service Manual.

If the timing is set correct and it still runing too fast could it be a problem with the pilot screws?

 

[TOHATSU GURU]

Re: Tohatsu 50D2 Timing

Not likely, but yes. It would be more likely that the idle adjustment screw is just set to high....

 

[Bobbyjoeufb]

Re: Tohatsu 50D2 Timing

Finally got the engine ticking over how it should be. But now have lost the top end power and boat struggles to get on the plane.

Tried playing with the timing and carbs but no luck, disconnected the linkage that operated the 3 carbs and operated them one at a time, noticed that the top carb when operating the throtle causes the engine to stall, whilst the other two cause the engine to rev; tried altering the mixture and changed the spark plug but still no joy.

Getting to the stage that I am considering taking it to my nearest dealer; which is a 200 mile round trip unless anyone else has any ideas?

 

[TOHATSU GURU]

Re: Tohatsu 50D2 Timing

Dealer is your best option.

 

[Bobbyjoeufb]

Re: Tohatsu 50D2 Timing

Engine finally sorted, Top Carb fast jet blocked. Which was strange as I had stripped and cleaned them already. So stripped them all again and used an airline and carb cleaner to make sure all the jets and channels were cleaned.

Whilst reattaching the carbs, I was lying at an obscure angle and found the timing mark! So managed to set the timing and resyched the carbs. Also replaced the spark plugs.

Had her out today and what a difference feels like a totally different boat nice and smooth and very fast! Hoping to take her out west next week with GPS and see how fast she is running.

 

[pvanv]

Re: Tohatsu 50D2 Timing

Moral to the story: Use the real Factory Service Manual as your guide; Don't bother with the aftermarket doorstop book.

 

[deejaycee_2000]

Re: Tohatsu 50D2 Timing

I have all the manuals you need for the D2 50hpp if you want ....