Originally Posted by BogMonster
The Humber Destroyer 5.8m I am looking at buying doesn't have an auxiliary engine included, so I need to figure out what that will cost on top of the price of the boat because that will affect what I can afford to offer!
Is a 4hp enough for this size RIB in often windy conditions like we have here? (seems to be a common size of aux engine) - the current owner reckons it isn't and a 6hp would be more like it - but he has a 4hp (admittedly not his!) strapped to the boat and I know a couple of others using this size of engine.
any good suppliers recommended for second hand/recon stuff please? doesn't seem to be much point in buying a new one that will (hopefully) hardly ever be used!
Get the biggest you and your aux transom bracket can handle. Many makes of motor use the same block for different sizes ie the 10 & 15 may be the same 2 pot block, just carbed, and bored differently, and will weigh about the same, so take the fifteen. I used a 10 on my 5.8 and it worked fine with the main motor trimmed up, progress was ok. At that time the 8 and 10 were the same block, and I could lift it ok. Bear in mind your room will be tight and space is also an issue. Mine was bolted behind the main centre jockey, not flat on the deck incase you take in water in a stuff. We used to rig it through the A frame when lowering at sea, and did tests regularly to hone our methods.
To my mind a 4 is 'pissing' into the wind. It also depends how far off shore you go etc. Our aux alsways has is own feul supply too I should say. We always carried neat petrol in the aux tank, and mixed 2 stroke at the last minute which gave us a handy reserve for the main engine should we have needed it. Hope that helps
Oh and PS, Buy a new one, since your life may one day depend on it, find the money somehow.