Gnasher Posted April 10, 2005 Report Share Posted April 10, 2005 im in the hunt for a real cheap back up engine, but whats the smallest HP that i could use on a 21footer? I may have a 4hp outboard but would that do for an emegancy? Dan Quote Link to comment Share on other sites More sharing options...
Coddy Posted April 10, 2005 Report Share Posted April 10, 2005 Hi Dan The biggest problem is the stength of the tide at the time. 4hp may be ok to head you home or even get you out of danger but it really depends on the engine. A Seagull Silver Centuary will produce about 4 to 5hp but some have large high thrust props which may be what you need. Weight of the boat is a consideration. A lightweight 4hp may not be powerful enough, not sure I would trust my 4hp aux coming in Poole entrance against the tide near the chain ferry! Best bet is to try someones engine on your bracket and see how it performs. Good luck Coddy Quote Link to comment Share on other sites More sharing options...
Bob F Posted April 10, 2005 Report Share Posted April 10, 2005 Based on my experience of a 4hp on a 16ft boat, I would suspect that realistically 10hp would be the minimum if you wanted an effective power unit. I rarely use my aux nowaways, perferring instead to go out with at least one other buddy boat. BF Quote Link to comment Share on other sites More sharing options...
Newboy Posted April 10, 2005 Report Share Posted April 10, 2005 I would say 6hp is minimum, but it also depends on what type of outboard. A 4hp high thrust WILL push a 25' <2 ton yacht in coatal area. The only problem is the tide is strong in this area and 4 hp isn't much if it's not a high thrust. Quote Link to comment Share on other sites More sharing options...
Paul D Posted April 10, 2005 Report Share Posted April 10, 2005 Bob, I don't use my aux either. It is too damn hard to start ! ( I tried it at Weymouth and it pushes the boat along OK but it really needs to be mounted so that it is fixed ( as opposed to using the tiller to steer the boat ). In the end I decided it was not much use as it was unreliable and just extra weight to lug around. If you are interested Dan, you can make me an offer for it ( old Mercury 4HP 2 stroke engine which I cannot get to start now ). Quote Link to comment Share on other sites More sharing options...
alun j. Posted April 10, 2005 Report Share Posted April 10, 2005 I've got a pair of oars.......... that worked well the one time I used them...... when I first launched, at Baiter, maiden trip, wind on - shore, so I rowed her out into deeper water to 'first start ' the engine. Yamaha never missed a beat since [ three years ago !!] Alun J. [ lives in a small world ]. Quote Link to comment Share on other sites More sharing options...
Barry Posted April 10, 2005 Report Share Posted April 10, 2005 Dan, 4hp on your boat will be too small if theres any tide running. It'll keep you out of trouble at best. I've a 21ft Tremlett and a 4hp 4 stroke mariner. It will just push the thing along at slack water. Ok I never really got it as an aux. It was purchased for the dinghy that gets used as a tender when the family want to play. Realisticaly a 6 will just about do it, but I would err on the safe side and go for 8horses as a min. Get a bracket and offer it up to determine wether you need a long or short shaft. If the prop isn't in deep enough you'll loose propulsion when the boat lifts and rolls in a swell. Steering with an aux on your type of boat is a right royal pain. Been there done that. I'got hold of an extention handle which makes things a bit easier. Quote Link to comment Share on other sites More sharing options...
domino Posted April 11, 2005 Report Share Posted April 11, 2005 I also have a 4hp Suzuki gathering dust in the garage if anyones interested. Quote Link to comment Share on other sites More sharing options...
Gnasher Posted April 11, 2005 Author Report Share Posted April 11, 2005 Cheers guys, I will hang in there until I find something like a 12HP jobby. Quote Link to comment Share on other sites More sharing options...
Bob F Posted April 11, 2005 Report Share Posted April 11, 2005 A quick tip in case anyone wasn't aware of it... When using your aux outboard you can still use the main wheel to steer the boat. Just tighten up the steering on the aux so that the boat moves forwards in a straight line, and then use your main wheel to steer the boat. No need to use the aux tiller. BF Quote Link to comment Share on other sites More sharing options...
Paul D Posted April 11, 2005 Report Share Posted April 11, 2005 Bob, Now that is a useful tip. The other problem I had was controlling the throttle on the aux. ( On the one I had you had to twist the tiller but it would go back to idle if you let go of the tiller. Any tips on how this could be done differently ? - not that it matters with my current engine as I cant even start the bloody thing now ) Quote Link to comment Share on other sites More sharing options...
Sam Posted April 11, 2005 Report Share Posted April 11, 2005 paul, i have the same engine as you for our dinghy but ours never used to twist itself back, hasn't been used for a while might take it down on the dinghy on saturday while dad is at work if he will let me [hopefully will] tight lines sam Quote Link to comment Share on other sites More sharing options...
Gnasher Posted April 11, 2005 Author Report Share Posted April 11, 2005 I noticed that a few of you have a couple of small engines that are non runners or not been used for a while. If you have a cheap price in mind for them then PM me. Dan. P.S only a week or so til my boat is hopefully ready!!!!!!!!!!!!! WAHOOOOOOOO!!!!! WATCH OUT bream on the 22nd, im comming at ya Quote Link to comment Share on other sites More sharing options...
Coddy Posted April 12, 2005 Report Share Posted April 12, 2005 Bob, Now that is a useful tip. The other problem I had was controlling the throttle on the aux. ( On the one I had you had to twist the tiller but it would go back to idle if you let go of the tiller. Any tips on how this could be done differently ? - not that it matters with my current engine as I cant even start the bloody thing now ) Paul There should be a friction grip screw on the twist grip somewhere. If you tighten this it will stop the throttle returning back to tick over. Alternative is to purchase a tiller extension arm which allows you to stand in the middle or in a better position in the boat. Coddy Quote Link to comment Share on other sites More sharing options...
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