DaySailer.org Forum

OK, well I did some searching, but cant realy find what Im looking for, so here we go...

Adding a outboard to a DSII...

How important is a long shaft on the motor? Can a normal shortshaft one work? Also, as far as HP. Seems most people get a 4hp, give or take a few... I was looking at a Sears 7.5hp with a short shaft for cheap. Is that to big/short for a DSII??

On my DS 1, I use a 4hp and it is more than adequate to power the boat out of the harbors on the lake. Additionally, it is strong enough to otor against a fairly stiff wind/wave condition.The engine weighs about 40 lbs. and I have a 3 gal. tank that fits sternward.
Not sure about the weight of the 7.5hp you are looking at, but likely it is not heavier than any 5hp from the 60's. The only concern with the short shaft is if it is on a fixed mount. If you have a mount that will lower the engine, it is not an issue. Otherwise, you will likely find that the prop comes out when motoring over wakes/waves.
Hope this helps.
Bob

my 3.5 gamefisher short shaft works great on my '80 DSII

Check this link for some info...

http://www.smalloutboards.com/shaft.htm

I have a DS1 with an Evinrude 4HP w/ long shaft and an adjustable bracket. I'll have to double-check how far down I set the motor. I may run it a bit lower than recommended.

Something like 2 1/2 HP should suffice to get the DS to hull speed (calm, not too many people in the boat). Anything more might come in handy to work against wind & waves (or push the boat on a plane ).

If you find yourself lacking for power with the 7.5HP, you might consider this approach:
http://image2-8.rcuniverse.com/e1/forum/upfiles/294813/Fd92098.jpg. It also deals intelligently with the short vs. long shaft question

Seriously, I would go with the smallest/lightest motor you can get, preferably one that can be kept in the cuddy when not needed, for balance reasons.

You could try a motor bracket like these:

http://shop.sailnet.com/product_info.ph ... s_id/12249
http://shop.sailnet.com/product_info.ph ... s_id/12250
http://www.iboats.com/Fulton_Outboard_M ... w_id.21259

The first two would allow you to mount the motor lower off the stern. The third one would allow you to mount the motor lower, and raise the motor out (or nearly out) of the water while sailing. I have one like it that I use with a 2hp Evinrude normal shaft, which is very light to carry, and moves my DSII along just fine on smaller freshwater lakes.

I use a standard shaft 1969 3.5hp Clinton on my DSI. I believe it is the same engine that Sears sold as the Game Fisher 3.5. My mount is fixed but the engine tilts so the prop is not in the water when sailing. Gas tank is integrated in the engine cowl. I carry only a gallon of additional fuel. This engine can run all day in rough conditions using very little fuel. Brad

Recently I bought a new Suzuki 2 1/2 short shaft, so I thought I'd add to this thread. The motor is mounted on a stationary mount on the stern (of the sort pictured in the first one of the links in this thread). The Suzuki weighs 30 lbs and is a breeze to carry when that's called for. The hp is more than enough to move my DS1 at a mile-high altitude, but then we have few tides (!) and though conditions can get rough once in a while, there are really no big waves to contend with except those temporarily caused by big motorboats. So it works very well here on Colorado lakes. (I figure at sea level, some of you might consider waterskiing behind this thing!)

I had a long shaft 3 1/2 and decided it was a problem for two reasons. First, it would not really tilt completely out of the water on the stationary mount (I could have adjusted the plate some I suppose to fix that) and second, it weighed over 40 lbs, and I thought that was pushing boat balance issues. The lighter weight short shaft works great, with one exception, and that is when sailing alone and I jump up on the bow for some reason, the cavitation plate becomes level with the water and any bouncing affects the water pump intakes. Of course, an air cooled motor like, say, the Honda 2 hp, wouldn't be a problem, but I happen to like the quieter, water-cooled Suzuki. For a four-stroke, this motor offers plenty of thrust per lb.

So far so good (I'm still breaking it in). Paid $700 but I've seen it online closer to $500.