Review: Yamaha 30H outboard motor

By: Andrew Norton

Presented by
  • Trade-A-Boat

The Yamaha 30H outboard motor has an excellent reputation for reliability and survival in a marine environment. It’s also straightforward to maintain and repair.

Review: Yamaha 30H outboard motor
The Yamaha 30H is known for its superb reliability in salt water. It is also renowned for its ease of maintenance.

Back in the early eighties one of the most popular small aluminium runabouts was the four-metre Quintrex Breezeabout. With its 1.8m beam it had stability unmatched by other similar runabouts and the flared bow deflected spray well at displacement speeds. The hull was rated to 35hp at the flywheel, which translated to a prop-rating (from 1983 onwards) of 31.5hp.

The most popular outboard motor on this hull was the Johnson 35, which in 1983 was de-rated to 30hp at the prop. The old Johnson 35 weighed 56.5kg in electric-start longshaft form, almost the maximum weight the Breezeabout was designed to handle. The Johnson 35 had a 521cc twin-cylinder crossflow powerhead, so it was beautifully smooth if a little thirsty for its output.

Trouble is the Johno 35 was discontinued in 2000 when Bombardier Recreational Products took over the bankrupt Outboard Marine. This left just three 30hp two-stroke outboards available, unfortunately all loopcharged. This meant extended trolling was out (I know this because I tried one on a Breezeabout), as were any four-stroke 30hp engines, all of which weighed more than 70kg and were therefore too heavy for a Breezeabout transom. In all those years no four-stroke 30hp outboard ever broke the 70kg barrier.

One of those two-strokes was the Yamaha 30H that had been recently upgraded for more torque by fitting a larger tune exhaust megaphone to improve exhaust gas scavenging and a needle-roller centre bearing for longevity. It also ran on a 100:1 fuel/oil mix, reducing oil costs.

 

YAMAHA 30H

The OEDA 1-star Yamaha 30H outboard motor has the second biggest piston displacement of any carbie two-stroke 30 currently available. It develops maximum power at only 5000rpm, whereas the Johno did so at 5500rpm. The output is 29.6 brake horsepower (746 Watts equals 1bhp) or 30 metric horsepower (735.5W). In electric-start longshaft form the Yamaha 30H weighs 58kg and is within what the Breezeabout can handle.

Like the Johnson, the Yamaha 30H outboard has a single carbie and mechanical ignition timing advance. But where it mainly differs is that instead of a forged one-piece crankshaft with capped connecting rods the 30H has a multi-piece crankshaft with solid conrods, just like the direct competition. One-piece crankshafts and capped conrods are rapidly being limited to four-stroke outboards.

A nice touch is that the electric-start Yamaha 30H retains the manual overhead recoil starter and has an engine overheat warning buzzer in the single-lever remote-control box. The alternator pumps out up to 6amp (wow!), but doesn’t have voltage regulation, so a starter battery of at least 70amp/h must be used to prevent the battery being fried on long runs to and from a favourite fishing spot.

Five trim positions are fitted but shallow-water drive is set by flipping up a lever, while the engine is held in full tilt by an archaic stopper knob.

Powerhead access on the Yamaha 30H outboard motor is excellent, with the spark plugs and bowl-type fuel filter easily reached. A 25:1 fuel/oil break-in ratio must be used for the first ten hours before switching to 100:1. And if premium unleaded (95 RON) is used so must a semi-synthetic oil such as Valvoline Outboard 2-Stroke.

Servicing intervals are every 100 hours or annually after the initial 20-hour check-up and the recreational-usage warranty is three years.

 

PERFORMANCE

Unfortunately a Breezeabout was not available for testing the review Yamaha 30H outboard, so instead we used a 4.1m Brooker Sportsman aluminium runabout. The outboard was raised 25mm on the transom to reduce lower unit drag as the Sportsman’s keel ended well ahead of the transom. We used a 13in pitch alloy prop to match the 2.08:1 gear ratio and handle our three-adult load, bringing the total displacement to 590kg.

With the choke and fast-idle lever set, even a weakling like me could manually start the engine with a firm two-hand pull. Running on 25:1 the new engine was a bit smoky below 1500rpm but reasonably clean above this. Below 2000rpm the big twin’s vibration gave my flab a great workout but from this rpm upwards was a little rougher than the Johno 30. The 30H got us to plane fairly quickly but through tight turns at 4000rpm there was some prop ventilation, so if your boat’s keel ends just ahead of the transom I suggest directly mounting the engine on it.

As expected, above 4000rpm my tinnitus sure got a workout, but this is one of the joys of working a carbie two-stroke hard. At least my flab got a break.

 

THE TRADE-A-BOAT VERDICT

As a repower engine for older aluminium runabouts the Yamaha 30H outboard motor is hard to beat, but don’t expect it to troll like the old Johnson 30. The Yamaha 30H is straightforward to maintain and repair and has an excellent reputation for reliability and survival in a marine environment.

See your local Yamaha Outboards dealer or contact Yamaha Motor Australia, phone (07) 3906 7000.

 

YAMAHA 30H OUTBOARD SPECIFICATIONS

TYPE Two-cylinder petrol two-stroke outboard motor

RATED HP 29.6/30

REC. RPM RANGE 4500 to 5500

DISPLACEMENT 496cc

BORE x STROKE 72 x 61mm

WEIGHT (ELECTRIC LONGSHAFT) 58kg

GEAR RATIO 2.08:1

YAMAHA 30H PRICE $4256

WARRANTY 3 years

 

YAMAHA 30H SEA TRIALS

RPM

SPEED

FUEL BURN

900 troll

2.2kts

1.2lt/h

3700 planing

10.9kts

6.4lt/h

4000 cruise

14.1kts

7lt/h

5500 WOT

23.8kts

13.5lt/h

 

COMPETING CARBIE TWO-STROKE OUTBOARDS

ENGINE

Mercury 30LW

Suzuki DT30

Tohatsu 30M

WEIGHT (KG)

57*

57.5*

57*

BHP/RPM

30.2/5125

29.6/5300

29.6/5500

DISPLACEMENT

429cc

499cc

429cc

PRICE

$3800*

$3500*

 $3800*

WARRANTY (YEARS)

5

2

 3

OEDA STARS

1

1

 1

* All-electric-start longshaft with remote control

 

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See the full version of this review in Trade-A-Boat #462, February / March 2015. Why not subscribe today?

 


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