outboard size for older Achilles 9ft HB inflatable?

[witzgall]

Hi all;

I just received a FREE 9 foot dingy. It is an older Achilles, white, with fiberglas bottom and transom. the model is HB90, and lists a 8hp as the max size for the boat. The boat needs some TLC, it has a slow leak and some of the glued on fittings could stand to be replaced, but hey, free is free.

I would like to have the boat plane easily with two people and stuff, but I don't need to feel the boat is ready to go out of control at any moment. The only HIB I has a 15' with center seating and a 40hp 4 stoke - that was wicked fast wide open, but the seating made it safe to manage the throttle.

So what do you suggest? 5hp, 6hp, 8hp?

Chris

[AnchorageGuy]

Well, if it lists 8HP as the maximum size than 8HP is the maximum size. The manufacturers put these sizes on for a reason and that is to safely operate the dinghy. Another issue with the older inflatables is the sizes are based on the 2 stroke outboards. The new 4 strokes are much, much heavier.

[witzgall]

Ok, let me put it another way. I would like to be able to plane the boat with two people and some gear, and do it with the smallest motor I can. I won't buy something larger than 8hp, so if that does not do it, oh well. but if I can get away with a 6, or 5, then that works better. Does that make sense?

Chris

[AnchorageGuy]

we had a 6HP on a dinghy of about that size and it would, with some effort get on plane with one person in it but with any other load, would not. Especially once you added another person, a full tank of fuel, and or any provisions.

[witzgall]

Chuck;

Thanks, that gives me the info I need. It looks like the 8hp is not too much engine for this size boat - I just have to decide if I want to deal with an 80lbs motor.

Chris

PS - A congrats to Cindy for her recent published articles in Sail and Spinsheet.

[sandy daugherty]

There are two issues with "max recommended engine": Weight and controllability. Since your Achilles is older, its talking about a 2 stroke engine. The odds are against you finding an 8hp 4 stroke that isn't too heavy. If you could borrow one, you could see how it handles with some weight (like the gas tank) forward, or find a good used 2 stroke, and leave a trail of blue smoke and oil slick!

If some of the stuff is coming unglued, can the rest be far behind?

[witzgall]

Is it that big of an issue? The difference in weight between a current Yamaha 4 stroke, at 80ish lbs, and a 2 stroke, at 60 ish lbs is ~20 lbs.

Nothing is coming unglued - the attachments that need replaced have the fixture ripped off - the patch portion is still firmly attached. We will see once I get it in the garage and start to work on it.

Chris

[By Invitation]

If your worried about being able to plane with a couple of people, I highly recommend installing lifters on the transom. I was amazed how much they helped our 10' HB dingy. I loved the way that they improved the performance so much that I have made my own set which bolt on to the stern of the dingy so they are more permanent. This was the only complaint I had with the original "lifters" is that you need to remove them when not using the dingy and they kind of "flop" around a bit. Our dingy went from planning with 3 "light" weights" to 4 adults. With 2 people we now plane at half throttle, use much less fuel and have much better control of the boat. The boat also gets up onto a plane without the bow lifting so far out of the water that you can't see where you are going. The bow stays down and the boat steers much straighter.

Check this out: http://cgi.ebay.com/ebaymotors/LIFTE...41310004r34339

[AnchorageGuy]

Originally Posted by By Invitation

If your worried about being able to plane with a couple of people, I highly recommend installing lifters on the transom. I was amazed how much they helped our 10' HB dingy. I loved the way that they improved the performance so much that I have made my own set which bolt on to the stern of the dingy so they are more permanent. This was the only complaint I had with the original "lifters" is that you need to remove them when not using the dingy and they kind of "flop" around a bit. Our dingy went from planning with 3 "light" weights" to 4 adults. With 2 people we now plane at half throttle, use much less fuel and have much better control of the boat. The boat also gets up onto a plane without the bow lifting so far out of the water that you can't see where you are going. The bow stays down and the boat steers much straighter.

Check this out: http://cgi.ebay.com/ebaymotors/LIFTERS-FOR-INFLATABLE-BOAT(RIGID)-%2F-DINGHY-%2F-OUTBOARD_W0QQitemZ120342046262QQcmdZViewItemQQimsx Z20081204?IMSfp=TL0812041310004r34339

By the looks of that photo one sure would not be able to turn that outboard very well with those things in the way. In addition backing down and pulling up on the beach and leaving would be a serious hassle. We have used products like "Dolfins" over the years and it has made a significant difference.

[By Invitation]

"By the looks of that photo one sure would not be able to turn that outboard very well with those things in the way"

When installed properly they have no affect on the turning the motor at all. They do have some quirks as I mentioned. The mounting needs to be more secure in my opinion, that is one of the reasons that I am making my own which will be much more stable and secure. I left them in place once while the dinghy was tied to a dock and when I came back the next day one of the lifters had been damaged and the mount was broken. I don't pull my boat out of the water or drag it up on the beach very often so I want them to be more permanent but still removable when I want. With the standard lifters you really need to remove them when not using the dinghy.