Outboard confusion

[langstonelayabout]

Nevertheless, great to hear a 4hp works for you, sounds like the 6hp will be okay if I can find a suitable prop for it.

Oh, and I forgot to mention; another reason for the 2 stroke 4hp was so that I can lift it into the cockpit whilst I'm sailing. The 9.9 leg and prop dragged boatspeed down something terrible.

I was also considering making a 'plug' for the outboard well like Seajet has made for his Anderson 22 (his design works a treat!) but haven't got to do it so far.

 

[winsbury]

Good point... the 6hp weighs about 25kg so potentially removing it while sailing is possible, I imagine your 4hp 2-stroke is a bit lighter than that, certainly on light air days it's a distinctly bright idea but I wouldn't fancy regularly moving even a small engine around on deck in seas like we had on Saturday.

How much speed gain do you get by removing and how much did you gain going down to the smaller engine size ? Do you still have the two flaps that close around the leg of the engine albeit still leaving a fairly bit hole ?

I also think a smaller engine has the considerable advantage of stowing it when we're not at the boat to reduce corrosion and the need for AF.

 

[owen-cox]

I worked on lots of mariner/yamaha 9.9 2 stroke in the early 90s and they were exactly the same carburettor and electronics as the 15Hp there was only a cam which opened the throttle on the carburetor which had a screw in it to increase the pitch of the cam and on the 9.9 it was not screwed in. Needless to say all the ones I worked on were 15Hp after I looked at them! people wer always surprised after I played with them. It also worked on a 5hp Evinrude that I owned it shared all its parts with the 9.9 so I tweaked that too and it was crazily fast with my little 3m dinghy. it would plane at 15 knots with 2 people easily. I did it predominantly to use it as a backup engine for my 1/4 tonner but it was great fun on the dinghy!

 

[2nd_apprentice]

Gosh, everybody seems to have this 6HP Mariner/Mercury/Nissan/Tohatsu engine! Mine lives in a well too, would be interesting to see how others solved the relief exhaust port problem (making it sound like a Death Star). As for lifting it while sailing: where do you put it? It's still a fairly heavy lump and being a 4-stroke rather sensitive to how it's stored.

 

[winsbury]

I think langstonelayabout is referring to a 4hp 2 stroke so laying it down in a locker or possibly hanging it on the pushpit rail isnt a problem but the 6hp 4 stroke is bigger, heavier and can only be laid down in one direction (handle down) which limits any idea of taking out of the well to improve performance to somewhat calmer sea days and would probably have to be manhandled down/up the companionway which frankly I think is asking for an accident to happen. Personally I like having the engine in case I need a quick burst of power for some reason but for racing perhaps there's an argument to remove it temporarily to get the best from the hull.