Tohatsu TLDI 40hp question

[Chillax]

Hello people,

After owning a Evinrude and Suzuki i bought a Tohatsu tldi 40hp.

I read on different sites from different people that a Tohatsu 40hp TLDI is identical to a 50hp except for the restriction plate in the trotle body, they all say that if you take the plate out the ecu will ajust itself. So a 40hp is a downtuned (restricted) 50hp.
I also read that dealers are taking these plates out on request when they sell a complete new motor. So there has to be atleast some truth in it.


To give a engine more air (unrestricting) won't damage it right?


I did read a lot on racing forums but also some of the lake and swamp forums, here in europe where i am from i read it on greek and Dutch sites.

Are there people here who have done this mod?

(Copy from my topic on another forum)

[Chillax]

I gues that the most of the people here only care to talk them selfs and about there own pride and joy.

Thanks for the info it was a real help to me.

[25XS]

I gues that the most of the people here only care to talk them selfs and about there own pride and joy.
Thanks for the info it was a real help to me.

First off. "Sorry" (that the unpaid, volunteer, hobbyist members here didn't give you instant service).

Have you compared the parts listing between the 40 & 50 TLDI's yourself? Do you have a parts listing? Did you ask the factory consumer help line this exact question, "Will any damage occur to my 40TLDI if I remove the throttle body restrictor?"
If you ask them that question, they can say, Yes or No... They CAN NOT recommend that you modify your factory engine or they are in big trouble with the EPA (USA) or EU (Europe).

The 40 & 50 TLDI engines have different part numbers for the ECU computer engine control, and I think the injectors are also different part numbers. Check the exhaust tuner part numbers under the powerhead as well, as they may be different like the 6/8/9.9hp 2-stroke Mercury engines that guys always say you can make into a 15hp by changing the carb (you can't). You mention that you have read about this topic on other sites that seem to have knowledge of the engines so your best bet may be to get what additional information you can from them.

[Chillax]

First off. "Sorry" (that the unpaid, volunteer, hobbyist members here didn't give you instant service).

Never asked about instant service, the fora i read about this mod is THIS forum thats wy i ask it here.
All forums have unpaid volunteers, and most of them have responding people on them especially in a topic thats bin viewd 150+ times.

No problem....

[chris3298]

I emailed Tohatsu here in the USA and the guy told me that the 40, 50 TLDI computers are different, he said taking that restrictor plate out the 40 will make the motor run lean and can cause damage to the motor. If these guys are taking the restrictor plates out these motors ask them if warranty is still covered on the motor. Why didn't you just buy a 50?

150 view maybe these people don't know much about these motors or just don't know about a restrictor plate.

[Chillax]

he said taking that restrictor plate out the 40 will make the motor run lean and can cause damage to the motor. Why didn't you just buy a 50?

150 view maybe these people don't know much about these motors or just don't know about a restrictor plate.
I just own a 40hp tldi and saw more than one topic on this issue. I am from The Netherlands so please explane to me "the motor run lean" what dus this mean?

Thanks for your reply.

[25XS]

Never asked about instant service, the fora i read about this mod is THIS forum thats wy i ask it here.
All forums have unpaid volunteers, and most of them have responding people on them especially in a topic thats bin viewd 150+ times. No problem....

The motor runs "lean" when the ratio of air to fuel in the combustion chamber (cylinder) is wrong with too much air being supplied.

Looks like you've posted this topic on several sites over the last few days... And you posted that you have already removed the restrictor plate from the throttle body and had good results on your boat. Hope the injectors and/or the ECU can keep up with the new demand for fuel for you, otherwise you'll burn the engine running it lean. The factory, and this reputable dealership both say the throttle body AND the ECU is required to make the upgrade from 40hp to 50hp.

http://www.internetoutboards.com/partdetail.asp?id=1049

You should put the restrictor back in, run a long test and then observe your sparkplugs immediately after a high speed run. Then repeat the test with the restrictor removed; observe the sparkplugs and if you see no change you may be fine. Maybe a temperature gauge on the cylinders & base of sparkplugs would give a reading (heat) that would indicate a lean mixture condition. You would then know if the injectors & ECU can compensate for the additional airflow and rpm on the engine. I noticed someone asked about recalibrating the TPS sensor... I agree that if you didn't touch it, that would not be necessary.

Good luck. I have no more information to provide.

Tom

[Chillax]

Tom and Chris,

Thanks for your input and explenation, i appreciate it.

I will try another prop with a higer pitch on it, so the rpm's will be where the belong.
But to see or know for sure that the engine is not badly affected by this on the long term is not easy to find out, i mean temp the cylinderheads i need special equipment and knowlege about these blocks to determ whats right and whats wrong. Being a direct injection i am also woried about the oil mixture being wrong.

About the Tohatsu dealers i am sceptical, they will never tel the public that a 40 is the same as a 50 begause it would look like they are scamming people with these blocks.
I think the truth lies somewhere in between.

Thanks with best regars,

Martin

[chris3298]

Being in the Netherlands i don't understand why you didn't buy the carburetor version of the TLDI. If it wasn't for our dam EPA laws I would buy one in a heart beat.
Sure I can buy a used 2 stroke but I wanted new.

[Chillax]

Being in the Netherlands i don't understand why you didn't buy the carburetor version of the TLDI. If it wasn't for our dam EPA laws I would buy one in a heart beat.
Sure I can buy a used 2 stroke but I wanted new.

Two words: gas price!

Its €1.90 a liter = more than $10,- usd a galon thats the reason.
But in The Netherlands we dont have EPA here they realy lost it, we even got a politic party called Animal-party thats figthing for the rigths of animals, the liberal leftwing, feminists, gays, treehuggers and hippie drug users the so called modern society ipad generation is taking over.
If i look at the US the south or Arizona, Texas, Louisiana well i would love to trade places with you!
Dont copy europe's value's moral or standards its a bad deal. EPA it aint so bad nou is it?

Hahaha okee thats of my chest.

[chris3298]

Honestly, I don't see the difference in gas milage from the TLDI and the 40 hp mercury that is a 2 stroke carb motor. I have a friend with one and it gets just as good of gas milage as mine. I bet over there yall don't have this problem with ethanol in your gas like we got here?

[Chillax]

I bet over there yall don't have this problem with ethanol in your gas like we got here?

I had two stroke's and four stroke's, known for there fuel hunger and weight. The TLDI is a good compromis its a good responding strong and simple engine. The only drawback is the need of a big battery, it won't run with out it like the E-tec's.

As far the problem with gas mixed with replacements (bio fuel's) yes we have it here, i am not sure its ethanol. Last year i replaced the injectors from my car begause of this bad fuel.
Startron worked for me.

[chris3298]

Dam sounds like worse gas then what we have. I to have a huge battery, I ended up going with a Optima there heavy but I have no problem with starting.

[Chillax]

I have an Exide.

This week a will put another prop on it, i now have a 12p going to try 13p Spitfire (4 blade) and a 14p (3 blade) and will see how it performs.

[chris3298]

With my jack plate jacked all the way up I need more pitch this 13 pitch isn't enough but not gonna buy another prop because the jack plate needs to be redrilled so i can jack it up higher.