Aux Engine Performance?

[Channel Ribs]

If you have an auxiliary engine it would be great if you could post the horse power of the aux, size of boat and attainable speed.

Thanks in advance

[bedajim]

6.5 M x 15 HP 2 ST = 7 Knts

Steering with main engine as rudder

Jim

[Richard Selman]

7m 9.9 Hp main engine steering -> 5 knots

Richard

[willk]

Out of interest - do you guys know what your speed would be if the main leg was out of the water? I'm not criticising, I'm just curious to know if there's much difference. I certainly would sacrifice a knot for a proper helm position too!

[kwil]

6m Mariner 4 Sailpower 2 stroke 4.5 - 5 Knots. Main engine up or down makes very little difference seems to be compensated by the shift in weight of the helm from right in the stern using the tiller to moving forward to the wheel if using main leg to steer.

Keith

[Richard Selman]

Makes little difference to my speed if the main engine is in the water. Also tried it in into F6 + waves and it only dropped to 4.5 knots.

Richard

[Channel Ribs]

Thanks for the data so far, keep it coming

[willk]

Thanks guys. Interesting

[Grouse]

6.5M Rib 6Hp Mercury = 4.5knots.

[BogMonster]

6hp Johnson 4 stroke on 5.8m Humber Destroyer about 4.5 knots
4hp Merc Sailmate 4 stroke with high thrust prop on Osprey Vipermax 5.8 about the same.

Likewise not much difference with leg up or down, less than 0.5kt anyway and much easier to steer!

Actual GPS speed generally fluctuates between about 3.5 and 6 knots over waves etc.

I find that about half throttle on the aux works best, full throttle gives very little more speed just more noise/vibration and higher fuel consumption.

Another useless bit of information is that with both the aux and the main engine running you can pretend you have twins and spin the boat on the spot