Tohatsu 30hp 4 stroke fuel injection V.s Tohatsu 50hp TLDI

[kris]

Hi guys how's everyone?! It's been some time since I have posted!  

I am seriously thinking of upgrading my current Toahtsu 30hp 4 stroke fuel injection (71.5kg) to a bigger Tohatsu 50Hp TLDI (93.5kg) on my Marino atom (15ft deep-V hull @ 310kg). The idea after all this is to keep the engine in the lower rpm range and hence, fingers crossed, I'll save fuel consumption and at the same time I'll have some back-up power  

Also, one more thing that is keeping me frustrated is that the boat takes up to 5 persons but if I have loads of stuff (for a days fishing for lampuki/alungi or for a swim) and we are 2 or 3 people, the boat won't plane...let alone if we are 4 or 5 persons!  

The engine is extremely economical when kept on the lower rpm range i.e. trolling speed (~4.5 knots) or even cruising speed (~15knots) at half to 3/4 throttle. On the other hand, when the boat is loaded and I push the throttle at 3/4 - full throttle it is a complete different story!

The boat is rated for a maximum 50hp outboard engine. Currently with my 30hp and 25L fuel tank + 2 persons, the boat reaches 22 knots at full throttle and 15-18 knots at cruising speed (3/4 throttle). This of course is when the boat has 2 persons on board and not so loaded OR else it has 3 persons and NOT loaded at all.

From my personal experience, I feel that the boat handles best up to 15 - 18 knots in calm/slightly choppy seas, of course boat handling experience and direction of the wind and waves play a very important role too  

However I think that the back-up of the extra hp will not be a loss...this of course is when I need it for those times when the boat has 3+ persons or is loaded, or when the sea is calm for a fun ride, or even when there are very strong currents and the engine is struggling to plane the boat.

The majority of the times we are 2 persons on board, with tackle and stuff for coastal fishing. Also, my no.1 priority still remains fuel consumption, however after sharing my view on the topic I would like to have your opinions on the subject

P.s. I have attached a fuel consumption chart, the red rectangles (in the attachment) show 'approx. fuel consumption in L per hour' (from tohatsu website), the other two columns show 'rpm' and 'gallons per hour'.

Thanks all much appreciated!  
Kris

[baghira]

What worries me is slow trolling with tldi's!
Can it go slow enough?
Will it pink?
Is it noisy?

[kris]

Sorry baghira but I am not that technical, what do you mean by pink? Yeah I think I know what you mean regarding slow trolling...especially for live bait trolling at dead slow speed as it is still a 2-stroke after all. Any of you guys own a tldi or heard about any issues?

[malvizzu]

What worries me is slow trolling with tldi's!
Can it go slow enough?
Will it pink?
Is it noisy?

Why so sceptic Silv?! My 50HP Etec goes down to 750 revs (even less if I make computer adjustment by an expert), trolled for 6 hours plenty of times at 1 knot and less and never had any issues. Fuel consumption is excellent and noise very minimal plus no vibration of engine at all. I assume that the Tohatsu 50HP TLDI is more or less like my engine but I stand to be corrected.

[malvizzu]

For members' information, Tohatsu have launched a new generation of 4-stroke engines ranging from 60HP to 250HP which will be available from PTR Marine of Rabat, who are sole agents for Tohatsu in Malta.

http://www.maltapark.com/item.aspx?ItemID=3029571

[kris]

That's what I found on Tohatsu's website:

"A unique feature on our TLDI® outboards is our user adjustable idle speed system.  By pressing in on the key switch, you are able to adjust the idle from 700 to 900 RPM’s  while you are using your outboard. Our TLDI® system will even remember the last setting and use this speed the next time you use your motor. In areas where currents are stronger or constantly changing, this makes time spent trolling all the more easier and pleasant. And because the TLDI® is a direct injection outboard, trolling for extended periods of time drastically reduces the occurrence of fouled spark plugs."

So strictly speaking...there is some fouling on the spark plugs at low rpms for extended periods BUT it should be drastically reduced.

@Malvizzu, yes my friend I know about the new range. In fact the range starts from 40hp-250hp! Today I had a chat over the phone with Shaun (ptr marine manager) regarding my issue and he has been EXTREMELY helpful (customer care way better than previous agent). Apparently, the 50hp TLDI and 50hp 4 stroke have a difference of ONLY 1.5kg!! So I am definitely considering the 4 stroke too!! I am visiting ptr marine showroom late next week to discuss things better with Shaun.

http://maltapark.com/item.aspx?ItemID=2987383

[baghira]

Well.....
I think that if I was to use a motor for trolling I would prefer a 4 stroke.

If you have an additional motor to use, then go ahead.....

That's my opinion after all....

Re: Noise.... Nothing can be compared to a 4 stroke. I have been on many new 2 stroke engines....
Obviously there was a very drastic change from the previous versions of 2 stroke engines, but so did the 4 stroke, and the sound of the new engines is simply amazing on these engines.

I have been last on Visa's boat powered by a large suzuki 4 stroke... The power/consumption and the silence of this outboard is amazing.

[baghira]

If you need the boat to run around... then go ahead with 2 stroke since that there are less moving parts, and less parts to fail... and running xosts are less than a 2 stroke.

That's my 2 cents...my opinion..

[kris]

My number one boat use will still be fishing, be it coastal or offshore (for offshore I would need a good 30-60 minutes to arrive to destination), but since I use it for other things I'd like to get some other opinions before I go for a 4 stroke or modern 2 stroke engine (like tldi, optimax, or etec). Maybe the new tohatsu 4 stroke has the best combination on the market if it's true that between the tldi and the 4 stroke there is a difference of just 1.5kg! (I'll check that next week)

Well guys, the factors I am considering to get the best combination are these:
cost to buy engine,
power-weight ratio,
fuel consumption,
noise,
maintenance costs,
local agent (because of any after sales).

I have done some research here on the forum and I read some great things regarding the etec, optimax, and suzuki but I don't have any experience with these engine.

It's true I have listed down tohatsu 30hp 4 stroke fuel injection V.s tohatsu 50hp tldi, but if you have any experience with any other brands please go ahead and post

[malvizzu]

Shaun of PTR Marine is extremely helpful and knowledgeable. I have been twice to his office already enquiring for an auxiliary 6HP 4-stroke. New stock should be in at the end of this month.

In MY opinion:

cost to buy engine – depending on your budget
power-weight ratio – definitely 2-stroke direct injection
fuel consumption – debatable, roughly I consume 10L or less for 6hr slow trolling
noise – I think 4-stroke
maintenance costs – definitely 2-stroke direct injection
local agent (because of any after sales) – depending from whom you buy  

As regards to spark plug fouling, I never had any issues and when I did my first full service, the plugs were still in very good working order. Still they were changed due to working hours. ETECs have a carbon additive fuel by BRP to add to petrol to avoid fouling when trolling at slow speeds for long hours. I will be using it this coming summer. Maybe Tohatsu have something similar. Whatever you buy, make sure you are convinced and within your budget. Cheers  

[baghira]

what do you mean by slow trolling?
Can you please remind us your size of boat and outboard?

Malvizzu obviously.

[kris]

Thanks for sharing your experience malvizzu! I see that in your opinion you are definitely a 2-stroke fan in almost all aspects!

@Malvizzu regarding the spark plugs fouling, I'll discuss things with Shaun in person, as till now we have talked over the phone. Regarding slow trolling...I second baghira...can you give more information regarding slow trolling please? Fore example, the weight of the boat, number of persons, and at what rpm/knots? If I remember correctly you own a 14ft fastfisher with a 50hp etec right?

@baghira...it would have been funny if you directed that question to me after the composition i wrote hahahaha

[malvizzu]

Petecraft 14 footer + Evinrude ETEC 50HP. Boat: 300kg. Engine: 110kg. Boat is not a deep-V like Kris'. Slow trolling: around 2 - 2.3 knots sometimes less. Always trolling with my father (around 70kg, i'm 75kg). On board 45L main fuel tank + 10L spare fuel tank + two 5L water tanks + fishing gear + other must accessories

[malvizzu]

Kris I cannot define myself as a 2-stroke fan I chose this type of engine after considering various opinions from fellow members on this forum before buying. If you search my initial posts you will realize how many questions I have asked before concluding purchase Before this boat I only had a 13 foot frejatina with a Mariner 9.9HP engine. So I definitely needed some feedback before upgrading.

[kris]

I must say that the etec is extremely economical as if you add up all the fuel & water tanks its as if there are 3 persons in all on board. At what speed do you troll malvizzu when you meant 'slow trolling' before?

I also read about the suzuki df50 (4stroke) to be unbeatable regarding economy & power ratio. Maybe any member who own one can give us their opnion

Yep I am no expert too in this field, that's why I am asking here before upgrading my engine. And yep, ultimately it still boils down to each individual case when purchasing anything