Aqualine 3.5hp Water Cooled
TM Aqualine 3.5 performance figures
Sea Jay 3.4 Punt, 5 inch pitch prop, third trim pin hole, total 275 KG including two adults and fishing tackle. Average of two way runs across a measured distance, calm water.
Throttle opening RPM KTS LPH L/NM* dB @ 3 metres
One quarter 1600 2.5 0.4 0.16 75.3
Half 2600 3.4 0.6 0.18 78.7
Three quarters 4000 4.6 1.0 0.22 83.6
WOT 4900 5.3 1.3 0.25 85.6
“Loop” of cruising including 10% WOT operation and averaging 4.0kts equals 1.0 LPH
Note the standard prop is perfect for this flat-bottomed punt.
ADDITIONAL TEST RESULTS
Savage 3.35 metre Mk 1 Gull dinghy, 5 inch pitch prop, total 270 KG including two adults and fishing tackle. Average two way runs across a measured distance, beam seas to 20 cm.
Throttle opening RPM KTS LPH L/NM dB @ 3 metres
Half 4200 4.6 1.0 0.22 83
WOT 5500 5.7 1.5 0.26 86
“Loop” of cruising including 10% WOT operation and averaging 4.0kts equals 1.1 LPH
Note that on this hull the engine is significantly under propped and would benefit from a 6 inch prop. Because the hull is easier to push at low speeds than the punt it delivers much higher speeds relative to throttle opening. Although this hull has a 16 inch transom to make up for the absence of an external keel there is no evidence of cooling water starvation but in following and quartering seas air trapped under the hull can reach the prop and cause the engine to race for a few seconds. This doesn't occur when pushing into head seas.
Normally on cold starting the fuel tank air vent and fuel cock are opened for about 30 seconds before starting the engine, always first pull with a few seconds of choke needed. However in an emergency situation the air vent and fuel cock can be opened, the engine cranked three times and then it starts. Very useful when motoring out from a lee shore.
On the Sea Jay 3.4 Punt the long external keel necessitates the need for a 15 inch transom to prevent propeller cavitation created by air bubbles along the keel. The 3.5 has a height of 16.4 inches from the transom bracket to upper anti ventilation plate so this additional depth below the transom allows water from under the hull to to flow over the upper plate, eliminating any possible cavitation. So although the 3.5 can cope with a 16 inch transom providing there's no external keel it's better suited to a 15 inch transom.
From new the engine has been run on premium unleaded (95 octane) mixed with semi-synthetic Valvoline 2 Stroke Outboard Oil. However during the most recent test standard non-E10 unleaded (91) was used with the only drawback being more oil smoke at lower revs.