The motors are a 3.5hp British Seagull, a 4.5 British Seagull, a 5hp Yamaha and a 2.5 Mercury, which will perform best on the same dinghy in the same time period?
The venue was Hout Bay Harbour, the time around 11am, Justin had brought his 15ft twin hulled GRP dinghy, his 5hp Yamaha was already fixed to the dinghy transom, It has just returned from a full service by the Anchor Boat Shop.
A similar Mercury 2.5hp to the one used, we found some interesting but not surprising results, the Yamaha 5hp was used first as it was on the boat already. For communication we used a pair of Icom M71 VHF handheld radios on a low setting, plus Justins Garmin V GPS, we then tried each engine to see what kind of top speed we could get?
Justin on our return to the slip, we are now two up and loaded with the four outboards, spare fuel and safety gear, this includes the 5hp Yamaha that is pushing us. With the boat empty and running on the far side of the harbour I recorded a speed at 10.1 knots. With that motor off and the smaller Mercury 2.5 hp fitted, I saw a top speed of 5.6 knots, with just half the power, thats not a bad speed. The speed at a quarter half throttle was still around 4.3 knots.
The test with the two Seagulls prooved little, both had problems running at even half speed, we have been told by John of http://www.save-our-seagulls.co.uk/ to check the Villiers carb jets. One was found to be quite blocked, now clean the motor runs well. The other Seagull is now on the bench and when thats running well we will continue the test, so keep an eye open for that blog.
Hout Bay Harbour is a part of the Table Mountain, Karbonkleberg nature conservation zone.
All pictures taken by R McBride, using a Canon G11 digital camera on an auto setting.
My thanks to Justin for the supply of his dinghy, outboard, GPS and for working out how
to do the U Tube from the video he made.
10/06/2012 , we have all motors now running well, Justin will return with his dinghy again and we will complete the test, we just need that same calm weather!