ON THE WATER
The 5 started easily hot or cold with little more effort needed than the 3.5. Interestingly, at one-quarter throttle it was faster than the 3.5 at wide-open throttle and used less fuel, resulting in the same fuel consumption around my cruising test loop. The pilot water discharge or tell-tale had the strongest flow I’ve ever seen from a 5, even when operating on the lowest shallow water drive setting, where power astern was still very good.Another example of Chinese manufacturers value-adding being able to use either a flushing drum or muffs is very handy. In the drum I found that running the 5 at fast idle in reverse prevented water being ejected from the drum and loaded up the engine sufficiently to reach normal operating temperature and clear out aluminium chloride deposits (commonly mistaken for salt) in the cooling water passages. Unusually, the engine also reached operating temperature on the muffs after about 10 minutes so I would use this method in preference to a drum because it’s quicker to set up and uses less water.
Spinning the standard eight-inch prop and pushing a two-adult plus fishing tackle load, the loan 5 got my 2003 Sea Jay 3.4 Punt to semi-planing speeds but because the torque fell off above 4000rpm the 5 was incapable of planing this hull, unlike the Mercury 5M and Tohatsu M5B which ran out to 13.8kt under identical test conditions spinning an eight-inch prop, though admittedly with a deeper gear ratio of 2.15:1. To reduce engine weight on the transom the remote fuel tank was used at all times.
Single Aqualine 5 on Sea Jay 3.4 Punt, 8in prop, total displacement 285kg, including two adults and fishing tackle. Average of two-way runs on Lake Macquarie, NSW, calm water, using fuel flow gear and portable high-tension lead tachometer. Range is in nautical miles from the 12L fuel tank with a 10 per cent reserve.
Throttle opening/rpm Speed (kt) Lt/H L/nm Range dB at 3m
One quarter/2500 5.4 0.9 0.17 65 81.6
Half throttle/3200 6.1 1.4 0.23 47 82.8
Three quarters/4100 7.1 1.9 0.27 40 88.1
WOT/4700 7.9 2.4 0.30 36 90.0
Loop of cruising including 10per cent WOT, averaging 4.0kt = 1.0Lt/h
Engine type Single-cylinder loop-charged premix two-stroke outboard
Rated BHP/MHP* 5.0/5.0 claimed at 5000rpm
WOT range 4500 - 5500rpm
Piston displacement 102cc
Bore x stroke 55 x 43 mm
Gear ratio 2.08:1
Dry weight 20kg
OEDA stars 1 (estimated)
*Brake horsepower/metric horsepower or PS
AQUALINE 5 REVISED PERFORMANCE FIGURES
Sea Jay 3.4 Punt, total displacement 285 KG including two adults and fishing tackle. On this hull the second trim position was the best for all-round operation.
7 inch pitch
Calm water, average of two way runs, range in nautical miles from a 12 litre remote fuel tank with a 10% reserve
Throttle opening Revs Kts Lt/h Lt/NM Range dB at 3 metres
One quarter 2600 5.0 0.9 0.18 60 80.4
Half 3400 5.8 1.4 0.24 45 84.5
Three quarters 4200 6.7 1.9 0.28 38 88.4
WOT* 5500 11.1 2.7 0.24 44 90.4
At WOT the hull was just planing and subsequently was more fuel efficient in terms of distance travelled for fuel used than at three quarters throttle opening.
Fuel consumption averaging 4.0kts with 10% WOT operation was 1.0 Lt/h, the same as with the 8 inch prop because the hull was able to plane.
I recommend the 7 inch prop be fitted as standard equipment. The trade off is worse fuel efficiency at displacement speeds but the 8 inch prop simply overloads the engine on small tinnies. Like all single cylinder outboards it performs better if it can reach the upper end of the recommended WOT rev range.