Tohatsu 50 TLDI

[nreid]

A Seattle dealer told me about the Tothatsu 50 with digitally controlled low pressure injection, and I have been reading about it on various internet sources. The injection system was developed by Orbit Engines in Australia and is the same used in Optimax Merc engines, apparently.

I'm slowly getting around to a question! If it weighs as much or more than a 50 hp 4 stroke (211 lbs.) , and still requires separate oil for the fuel system, and makes more noise than a 4 stroke, is there any real advantage to this engine? Anyone tried one?


Thanks again,

Nick

[zod550]

i have had a #of 2 strokes and i am currently running a yamaha f100 4 stroke. granted this is a bit bigger then what you are looking for however i would not go back to a 2stroke after owning a 4stroke, hope this helps chris

[Keith Hart]

Hi there

I realise that my reply only applies to smaller engines, but here it is anyway. I purchased a Mariner 15hp 2 stroke. It was considerably lighter than the 4 stroke version. This was important as I intended to (and do) transport the boat (sib) and engine in the back of my estate car. Also being a 2 stroke I can disconect the fuel and run the engine untill it is empty. Then I can lay it down in the car and there is no oil to leak out etc. This has worked well so far.

Keith Hart

[batfalcon]

In my opinion the new generation of 2 stroke engines like the Optimax or the High Pressure Fuel Injection, devloped by Yamaha (I can't recall the model), or the FICHT models of OMC, (when produced), were MUCH promissing developments. The 4 strokes on the other hand have nothing new to show up. Just the same old method, installed and configured for marine use.
Personally I would go for a 4 stroke for one and only reason. Most of the new models are being tested through us.
I wouldn't want to be a victim of a failed experiment !!

Michael

[nreid]

Thanks for the information. I agree that the testing of new technology often happens through us and I dearly want to avoid that pitfall.


Nick

[sasa]

I don't have any experience with Tohatsu engines, but I found a test in the Swedish powerboat magazine Vi Båtägare . They compared Mercury 4-stroke, Tohatsu Orbital and conventional 2-stroke Tohatsu. Test boat was a 4.7 m long GRP boat, weighing 280 kg without engine.

The Mercury is the fastest engine, some 2.5 knots faster than the Tohatsus on average (3.5 knots faster at WOT).

The Tohatsu Orbital is the most fuel-efficient engine. It is interesting that the conventional 2-stroke Tohatsu is more fuel-efficient than the 4-stroke Mercury at speeds between 20 and 24 knots!

The acceleration is very even, but the 2-stroke Tohatsu has a slight edge here.

The 4-stroke Mercury is, as expected, quieter than the other two engines, especially at lower revs.

The Mercury is heaviest at 107 kg, the Orbital in second place at 83 kg and the 2-stroke is lightest at 67.5 kg.

When it comes to price the 2-stroke is obviously cheapest. It costs SEK 42000.00. The Mercury costs SEK 57500.00 and the Orbital costs SEK 66990.00.

So, it would seem that the 4-stroke is the way to go. This is also the conclusion in the article.

Hope this helps!

Sasa

Divide the amount in SEK by 11 to get US$, and divide it by 15 to get UK £.

[Alan]

Andy Clark, the outboard guru who writes in RIB International has a good article on the Tohatsu TLDI on his website:

http://www.bosunsmate.co.uk/tohatsu.htm

As he says its basically Optimax under another name.

We are now running a Merc 150 Opti on Yellow Tang and are EXTREMELY impressed with its peformance and economy. Acceleration is amazing, top speed is excellent and economy compared to the old fashioned 2 stroke it replaced is unbelievable.

One word of caution - Team Gem ran a Tohatsu 50 (Not sure whether it was a TLDI) in RB4 and ultimately had saddle bracket failure. Mind you so did we in Team Spirit on our original Suzuki.

HTH,
Alan