Question for Elvin...

[Salmon Tub]

Dear Elvin, <br /><br />I was wondering regarding the TLDI's, since the idle is computer controled, rather than controlled mechanically, how often does the computer monitor and correct the idle, in other words, on my 90 now (carbed), you can see the effects of water conditions and weather on the idle speed. An example would be that if I am trolling with the wind and turn into it, I notice that the engine may lug a bit until the boat gains momentum again into the new direction. This is even more noticeable when there is large wind wave and swell action that is constantly effecting the momentum of the hull. In glassy flat calm conditions, once the hull gets going, the motor offcourse keeps a nice steady idle with little shudder. The variances I am talking about are only about +/- 50 rpm, but you can hear them more than see them in the gauge, and you can notice it by the way the engine will shudder a bit more. Just wondering if the computer on the TLDI's refreshes fast enough to compensate for these conditions. Thanks for your help!

 

[TOHATSU GURU]

Re: Question for Elvin...

Its an instant change. The ecu monitors at the rate of 100 times per second and compensates without a time lag. You do not see any kind of lag in Direct Injection Outboards. The Mercury's and Yamaha's are the same...or at least close.

 

[Salmon Tub]

Re: Question for Elvin...

Elvin thanks for the quick response. That being the case, I would imagine that the ECU does minute adjustments to the amount of fuel injected by the injectors in order to sustain a constant rpm. I would imagine that air is introduced via crankcase vaccuum only so I imagine that the computer does not control the flow of air. This being the case, I imagine that the mixture in such a case is constantly fluctuating to a small extent. If these assumptions are correct, have there been any "problematic" operating ranges such as long periods of trolling in heavy seas, or fast trolling? My main concern is would there be any adverse effect on say a TLDI 70/90 that has been trolling at idle for say 4-6 hours continuously, or trolling at say 1600-1800 rpm for the same period. The later would be for tuna in our local waters at a speed of 7-8 knots. The later has historically always been problematic for carbed 2 strokes and as I understand, under certain load conditions, the nail that sealed the coffin of the original Ficht motors. I run my 90A with a 13.75x15 prop now and would do the same on the TLDI 70/90 in order to troll at the speeds I need. Again, your info is greatly appreciated, Thank you.

 

[TOHATSU GURU]

Re: Question for Elvin...

The Ficht engines were plagued with design flaws and were rushed to market a lot sooner then they shoud have been. Better them then us. The fundamental difference between the Ficht/HPDI and the TLDI/Optimax(should have been called Optibomb) is that we use a low pressure injection system that has always worked(thank Orbital). We have never had any problems with extended idling. The Optimax engines were rushed and they expierenced the same kind of systemic failures as the Ficht. The HPDI's also had problems as they were marketed a little too soon as well. Tohatsu started development early and had time for development...it wasn't that hard since they only have a few models with it. <br /><br />I think you would be well pleased with the TLDI, but you would probably be just as happy with a 4-stk too. The real advantage of a direct injection outboard is the quicker power availabiltiy. If your not looking for jack rabbit starts you could go either way. It kind of depends on your local dealer support. If your local Honda dealer is a jerk and the Yamaha dealer thinks they are made out of gold and the Mercury/Suzuki dealer is always closed due to investgations....then Tohatsu wins hands down.