Tohatsu TLDI 90 Outboard Motor Review

Originally published in TrailerBoat #283, June / July, 2012.

It’s been a long time coming but it’s finally here — the direct-fuel-injection two-stroke Tohatsu 90hp. When it comes to emissions, this engine competes directly with the three-cylinder Evinrude E-TEC 90 and Mercury OptiMax 90 engines.

TOHATSU TLDI 90

The Tohatsu TLDI 90 outboard motor still uses the Orbital Combustion Process (OCP) developed by the Orbital Engine Corporation of Western Australia. This process injects an atomised air / fuel mix directly into the combustion chambers. In both stratified and homogenous modes the result is incredibly low fuel consumption when slow trolling, yet plenty of power and torque when it’s needed on the plane. The process is widely acknowledged in the marine industry as one of the most reliable DFI systems available, and it’s even used in OptiMax outboards.

To gain “3 Star” compliance Tohatsu increased the air injection pressure on this engine from 80 to 94psi and the fuel-injection pressure from 90 to 104psi. Standard piston rings have also been swapped to “keystone” rings to reduce combustion chamber gas “blow by”, and the belt drive for the air compressor has been relocated to the top of the flywheel for easier servicing. The starter motor has also been swapped from a direct-drive 1.0kW unit to a geared 1.4kW motor for instant starting when cold. However, a minimum 100amp/h deep-cycle battery is still recommended as the OCP doesn’t like low battery voltage.

POWER

The Tohatsu TLDI 90 outboard motor develops 88.7hp at 5500rpm with a wide open throttle (WOT) rpm range of 5150 to 5850 from its three-cylinder 1267cc loopcharged powerhead. The under-flywheel voltage-regulated alternator produces up to 40amp and in standard longshaft form the unit weighs a reasonable 150kg.

The powerhead-mounted oil tank on the Tohatsu TLDI 90 outboard holds 4lt and is accessed via a hatch in the now rounded upper cowl, which looks so much better than the 2 Star 90’s angular cowl. The lubricating oil is injected via an electric oil-pump to where it’s needed.

National Tohatsu distributor Lakeside Marine recommends servicing the 90 every 50 hours or annually after the first service at 10 hours. Providing this work is done by an authorised Tohatsu dealer, the recreational-usage warranty coverage is three years. Lakeside also recommends using either Quicksilver DFI oil or Evinrude / Johnson XD100.

ON THE WATER

Our review Tohatsu TLDI 90 engine unit was mounted on a Makocraft 4.85 Frenzy side-console, factory-upgraded to 90hp and swinging a 17in pitch stainless steel Power Tech prop. With two adults aboard (helping achieve a total displacement of around 900kg) I found the demo 90 to be more than adequate for this hull, and it would have easily handled a third person onboard.

Running on premium unleaded (95 RON) the Tohatsu TLDI 90 engine started instantly hot or cold. No oil smoke appeared at any time and there was just an occasional whiff of oil smell. By depressing the starter key for one second at a time I was able to alter the trolling rpm from 700 to 800 or 900, then back again and trolling at 700rpm. I found the vibration levels to be slightly higher than an E-TEC 90 but lower than an OptiMax 90 outboard.

The boat maintained a clean plane at surprisingly low rpm and through tight figure-of-eight turns at 4000rpm no prop ventilation occurred. Even at WOT the Tohatsu TLDI 90 outboard motor was pleasantly quiet and we could hold a normal conversation at the helm.

THE TRADE-A-BOAT VERDICT

Tohatsu has retained all the user-friendly features of the 2 Star 90 in a more environmentally-friendly package. The 3 Star model is more fuel efficient overall yet still has the inherent reliability of the proven OCP, which has been on the Aussie market for around 15 years in TLDI and OptiMax engines.  The finish and paintwork are excellent and with regular maintenance the 90 should provide a long, trouble-free lifespan.

PRICE

As of May 2012 the longshaft Tohatsu TLDI 90 outboard motor has a price of $13,709 RRP, with a spare Power Tech propeller costing $900.

TOHATSU TLDI 90 PERFORMANCE

Makocraft 4.85 with 17in pitch stainless Power Tech prop and two adults onboard.

COMPETING OUTBOARDS