Tohatsu 50hp 2 Stroke TDI or 4 Stroke Tohatsu 50hp

[jackreno]

Anyone had experience with both, the newer TDI 2 stroke vs the 4 stroke Tohatsu 50hp, what is the performance difference, noise, fuel usage, maintenance, etc..

Weight and price is about the same so no issues there.

I am going to buy a new Tohatsu 50hp for my Bombard C4 but cant decide on the 2 stroke TDI or 4 stroke..

What would you buy and why, I need help with my decision..

[beamishken]

I've not had experience of either engine so can't comment on performance or economy although I'd expect the 2 stroke to have marginaly better bottom end. And the 4 stroke better economy
Based on many years of using and fixing engines I'd lean towards the two stroke.
That opinion is based on a few assumptions
1)your a typical UK boater who won't do 100's of hours a year and the engine will be laid up occasionally for long periods
2)Not taking into account cost of purchase or resale.

The two stroke engine was for many years the benchmark for outboards because of the simplicity and ease & lack of required maintenance this realy only changed because of emmisions regulations.
Newer two strokes are high pressure direct injection which complicates them somewhat but given good fuel filtration there is still a lot less moving parts to go wrong than a 4 stroke.
Modern 4 strokes in my opinion don't stand the test of time in the same way as their 2 stroke predecessors we see engines now wrecked due to internal corrosion of the tiny waterways and water ingress into oil sumps. They also need more maintenance in terms of oil and filter changes and timing belts or chains can fail,valves and springs can also fail due to condensation during layup.

So for typical UK use and assuming you will keep the engine a long time then it would be the two stroke for me

[jackreno]

My last 3 boats had 4 strokes, 1 was a carb and other 2 were fuel inject, they were all good motors but slow out of the hole and was thinking a 2 stroke this time around, this might be my last boat and will keep it for years so trying to get the right motor this time around.

Might as well and try a 2 stroke this time, at least no annual oil/filter changes.

Was also looking at the gear ratio of the 2 stroke at 1.85:1 and the 4 stroke at 2.08:1, would this make the 4 stroke perform the same than ?


Here is the Tohatsu 50hp TLDI info, it is a low pressure direct inject 2 stroke..

Tohatsu 50hp TLDI

[GI-SYD]

Originally Posted by jackreno

Anyone had experience with both, the newer TDI 2 stroke vs the 4 stroke Tohatsu 50hp, what is the performance difference, noise, fuel usage, maintenance, etc..

Weight and price is about the same so no issues there.

I am going to buy a new Tohatsu 50hp for my Bombard C4 but cant decide on the 2 stroke TDI or 4 stroke..

What would you buy and why, I need help with my decision..

No experience yet, but about to get a 2-stroke Tohatsu 50, which weighs in at 75Kg, for a new Gemini Zapcat. The TDI weighs 94Kg, add oil and you are 20Kg heavier! Just like the Zapcat, your C4 is a light boat and the TDI may be a lot of weight on the transom. That, and price, would be my main consideration. Noise, fuel is all much of a muchness.

[jackreno]

Originally Posted by GI-SYD

No experience yet, but about to get a 2-stroke Tohatsu 50, which weighs in at 75Kg, for a new Gemini Zapcat. The TDI weighs 94Kg, add oil and you are 20Kg heavier! Just like the Zapcat, your C4 is a light boat and the TDI may be a lot of weight on the transom. That, and price, would be my main consideration. Noise, fuel is all much of a muchness.

The C4 Bombard transom is rated for 50hp and 235 lbs/107 Kg motor weight, plus I am installing a jockey seat I will be seating in middle/forward of the boat, this should also help with the max weight in back but not over transom specs..

The TLDI in 40hp weighs the same, no way am I going to 30hp, had that on my last boat, I want extra hp and max speed when needed..

[GI-SYD]

Originally Posted by jackreno

The C4 Bombard transom is rated for 50hp and 235 lbs/107 Kg motor weight, plus I am installing a jockey seat I will be seating in middle/forward of the boat, this should also help with the max weight in back but not over transom specs..

The TLDI in 40hp weighs the same, no way am I going to 30hp, had that on my last boat, I want extra hp and max speed when needed..

Sounds like a plan! I agree, always go max HP. Go for the TDI, nice to have the injectors and auto-oil. What are your USD prices for the 2-str and the TDI?

When you get it, please make a good video, I would like to see that combo in action, should fly!

[Roflhat]

The TLDI is meant to be an excellent engine, I've not used one but heard good things. Apparently they have a decent bit more power than the standard 2 stroke tohatsu too. I think the standard 2 strokes are harder to get in the US? As said that would be a good option, nice and light

[jackreno]

Originally Posted by GI-SYD

Sounds like a plan! I agree, always go max HP. Go for the TDI, nice to have the injectors and auto-oil. What are your USD prices for the 2-str and the TDI?

When you get it, please make a good video, I would like to see that combo in action, should fly!

Around $6000 plus tax for a new TLDI 50 hp.

[GI-SYD]

Originally Posted by Roflhat

The TLDI is meant to be an excellent engine, I've not used one but heard good things. Apparently they have a decent bit more power than the standard 2 stroke tohatsu too. I think the standard 2 strokes are harder to get in the US? As said that would be a good option, nice and light

Hey Roflhat, I will be running my brand new Tohatsu M50D2 stock standard to begin with, on the Zapcat. What would be the first, easy mods I can do to it? Just simple stuff, to make it more reliable, easier to run, easier to live with, etc.

I will have to run it in first, get used to the boat and the motor, we get pretty choppy waves and strong winds here in Sydney, this time of year, so I am not looking for top speed, I am looking for reliability and efficiency.

[GI-SYD]

Originally Posted by jackreno

Around $6000 plus tax for a new TLDI 50 hp.

The M50D2 is AUD $4300 incl 10% GST (our sales tax), so about USD $3,000 plus tax. Half the money!

[Roflhat]

Originally Posted by GI-SYD

Hey Roflhat, I will be running my brand new Tohatsu M50D2 stock standard to begin with, on the Zapcat. What would be the first, easy mods I can do to it? Just simple stuff, to make it more reliable, easier to run, easier to live with, etc.

I will have to run it in first, get used to the boat and the motor, we get pretty choppy waves and strong winds here in Sydney, this time of year, so I am not looking for top speed, I am looking for reliability and efficiency.

They're pretty good reliable engines generally speaking, brand new should be alright for a good few years anyway. The most troublesome parts are the fuel pump which is crap, and the coils which is pretty unreliable. I replaced the coils on mine with Naruku motorbike coils, easy to do and a lot more reliable. Even better use Yamaha 50-90hp coils, or Tohatsu 70hp coils like the zapcat racing guys over here do, no performance gain just reliability.

Carbon reeds are always good, either Boyesen or Chris Carson Marine. Slight performance improvement but it means if they break you won't have bits of steel in your cylinders.

Best money spent is props, if you're playing in surf then 13-15p is good all round, probably semi cleaver is best, vengeance, quicksilver are good too. Solas props are alright.

After that, you can get more performance with velocity stacks - Forge Marine
and you can skim 1mm off the cylinder head for more power, TSR make a head too but not sure how it does for reliability.

Other than that just change the plugs fairly often and spray the engine down with duck oil or wd40 after every use and flush it with fresh water

[Roflhat]

After a few years you might want to change the engine mounts, the standard ones are rubber and will break at some point, I did mine when the engine was 9 years old and they were still decent but folk have had them break in the first year. You can either go solid metal ones or go poly plastic, which I would recommend, less harsh on your arms when driving.
If you want to go for more performance you want to weld the crank to stop it twisting, it's only pressed together. But for standard use you should be grand

[GI-SYD]

Originally Posted by Roflhat

They're pretty good reliable engines generally speaking, brand new should be alright for a good few years anyway. The most troublesome parts are the fuel pump which is crap, and the coils which is pretty unreliable. I replaced the coils on mine with Naruku motorbike coils, easy to do and a lot more reliable. Even better use Yamaha 50-90hp coils, or Tohatsu 70hp coils like the zapcat racing guys over here do, no performance gain just reliability.

Carbon reeds are always good, either Boyesen or Chris Carson Marine. Slight performance improvement but it means if they break you won't have bits of steel in your cylinders.

Best money spent is props, if you're playing in surf then 13-15p is good all round, probably semi cleaver is best, vengeance, quicksilver are good too. Solas props are alright.

After that, you can get more performance with velocity stacks - Forge Marine
and you can skim 1mm off the cylinder head for more power, TSR make a head too but not sure how it does for reliability.

Other than that just change the plugs fairly often and spray the engine down with duck oil or wd40 after every use and flush it with fresh water

Thanks! That is exactly the practical stuff I needed! Today I have ordered a Power Tech Stainless Steel Performance Propeller SCB3, in 14p, for AUD $495. I will do the run-in with the standard alu prop, and get a speed reading with that one, and then put this Power Tech prop on, see if it makes a difference

[fel2]

Bump !