I've got one of those new BossBoats dinghy. Appearance wise, it looks identical to any inflatable rigid bottom dinghy. The big difference is that it's fiberglas instead of rubber. No, you can't collapse it for storage but it won't rot, puncture or leak. My question is this. It's only 8.5 feet long and weighs about 120 pounds. I've got a 6 hp Suzuki on it but it won't plane. Never having had a dinghy before, I wonder how much horsepower do you need to plane. For those of you who have an inflatable, should 6 hp do it or do I need to upgrade to a 9.9 or bigger outboard. Somebody told me that 6 hp should be sufficient and, since mine won't, do you have any idea why the engine isn't giving me the power I need? It's a brand new, out of the box engine. Any ideas appreciated.
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flying dinghy... more power?
I remember reading Latitude 38 under the Baja Ha Ha recommendations of what you need on the trip. In there they talked about what kind of horsepower needed per person for planning. You may want to look it up. Also the design of the dinghy bottom is important, flat vs V shape(Vshape better). hope that is of some help, there are others on this site with much more knowledge. abe
I remember reading Latitude 38 under the Baja Ha Ha recommendations of what you need on the trip. In there they talked about what kind of horsepower needed per person for planning. You may want to look it up. Also the design of the dinghy bottom is important, flat vs V shape(Vshape better). hope that is of some help, there are others on this site with much more knowledge. abe
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Steve G
Rick
I may be telling you something you already know, but to put it in basic terms (avoiding the physics; coefficient of friction etc.) a boat planes when the applied thrust is great enough to cause it to "climb" over its own bow wave. Once achieved drag lessens with additional power. So: You really don't want "just enough" to make it plane because (aside from sticker price) a little extra power after it planes will go a long way. The question is whether 6 HP is enough, and it SOUNDS like it is unless you're a rather big guy. Questions: (I'm not familiar with the make) Is the bottom shaped like an inflatable - is it rigid and basically flat? Inflatables don't have a chine per se, but thier design causes the water pressure to be forced under the boat rather than around it. A displacement design is efficient for low HP, but will never plane. Is the tilt on the motor set correctly? Too low and you'll just plow, too high and you'll just point skyward. Is the motor producing its intended HP? I bought a Mercury (we used to call it the "Evil Mercury") The throttle and choke were set wrong, and it never started right until I took apart the carb myself and cleaned it. Now it's three years old and runs FAR better than the day I bought it. Good luck! I hope others can help.
I may be telling you something you already know, but to put it in basic terms (avoiding the physics; coefficient of friction etc.) a boat planes when the applied thrust is great enough to cause it to "climb" over its own bow wave. Once achieved drag lessens with additional power. So: You really don't want "just enough" to make it plane because (aside from sticker price) a little extra power after it planes will go a long way. The question is whether 6 HP is enough, and it SOUNDS like it is unless you're a rather big guy. Questions: (I'm not familiar with the make) Is the bottom shaped like an inflatable - is it rigid and basically flat? Inflatables don't have a chine per se, but thier design causes the water pressure to be forced under the boat rather than around it. A displacement design is efficient for low HP, but will never plane. Is the tilt on the motor set correctly? Too low and you'll just plow, too high and you'll just point skyward. Is the motor producing its intended HP? I bought a Mercury (we used to call it the "Evil Mercury") The throttle and choke were set wrong, and it never started right until I took apart the carb myself and cleaned it. Now it's three years old and runs FAR better than the day I bought it. Good luck! I hope others can help.
A Wing should do it.
You need to put a wing on the shaft of the engine. Afriend of my had the same problem and that is how he fixed it. Check where you bought the engine. Paul
You need to put a wing on the shaft of the engine. Afriend of my had the same problem and that is how he fixed it. Check where you bought the engine. Paul
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Larry Long
Daryl has the answer
My 9.8 Tohatsu will plane my dinghy with me and 3 grandsons with a combined weight of more than 500#. However, If I sit in the very back of the boat I can prevent it from getting on plane with just me aboard. If I shift my weight foreward just slightly it will immediately jump on plane.
My 9.8 Tohatsu will plane my dinghy with me and 3 grandsons with a combined weight of more than 500#. However, If I sit in the very back of the boat I can prevent it from getting on plane with just me aboard. If I shift my weight foreward just slightly it will immediately jump on plane.
not all created equal.
Rick: There was an article several years ago in Practical Sailor about dingies. They are not all the same. Six horse seems a little on the weak side. You should try have a light weight person try it. Also try moving your weight as far forward as possible. The 'dolfin' fins help a little but are not the ultimate answer either.
Rick: There was an article several years ago in Practical Sailor about dingies. They are not all the same. Six horse seems a little on the weak side. You should try have a light weight person try it. Also try moving your weight as far forward as possible. The 'dolfin' fins help a little but are not the ultimate answer either.
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Rick
Thanks for the help but I'm stymied
The Bossboat dinghy has a nice V-hull and the manufacturer shows that it planes nicely. I'm about 200 pounds so, although no lightweight, you'd think that isn't excessively heavy. A recent review by Practical Sailor on a bunch of 4 hp outboards indicated that they got an Achilles 10 footer to plane with each of those engines. I checked the Achilles web site and see that it weighs more than my dinghy. I have to wonder if the engine is churning out the right horsepower because it sound like, although maybe not much hp, it should be enough to get it going. Any ideas on how to check if the engine is doing what it should do?
The Bossboat dinghy has a nice V-hull and the manufacturer shows that it planes nicely. I'm about 200 pounds so, although no lightweight, you'd think that isn't excessively heavy. A recent review by Practical Sailor on a bunch of 4 hp outboards indicated that they got an Achilles 10 footer to plane with each of those engines. I checked the Achilles web site and see that it weighs more than my dinghy. I have to wonder if the engine is churning out the right horsepower because it sound like, although maybe not much hp, it should be enough to get it going. Any ideas on how to check if the engine is doing what it should do?
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Pete
check with the manufacture
or read you manual,it should give you minimum horsepower needed to plane and what weigth you can carry and still be on plane. Beside moving forward for weigth distrubtion (you may want to think about getting a throtte handle extension)You may also be proped wrong. I know that my dinghy engine has four prop specs depending on what the entire package weights and what you want for performance. you may also need to check that you installed the engine correctly and that it has the correct postion (angle) compared to the transon.Just some thougth hope they help !
or read you manual,it should give you minimum horsepower needed to plane and what weigth you can carry and still be on plane. Beside moving forward for weigth distrubtion (you may want to think about getting a throtte handle extension)You may also be proped wrong. I know that my dinghy engine has four prop specs depending on what the entire package weights and what you want for performance. you may also need to check that you installed the engine correctly and that it has the correct postion (angle) compared to the transon.Just some thougth hope they help !
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Steve G
Rick
A lot of good ideas here, but let's see if we can find out some things without spending anything. Do you know someone who has a rigid inflatable? I have a West Marine inflatable w/a 3.3 HP. It will plane off with my 115 lb son in it (not with 220 lbs of yours truly). If I put a 6 HP on that, it would go like a bat out of hell (I put the 3.3 on because my 13 yr old son uses it). If you don't know anyone who can help, get a lightweight person to sit in it (foreward), just to see if it's a weight issue, but I doubt it is. Props? That COULD be the issue. It could have a power prop (low pitch) designed to push a small sailboat, but even that should get it to plane. Changing props would be about the last thing I would try. Don't bother with a speed prop. With that balance, it would just take too much "bite" and the energy would be converted improperly. Put the tilt on the middle adjustment. Good luck
A lot of good ideas here, but let's see if we can find out some things without spending anything. Do you know someone who has a rigid inflatable? I have a West Marine inflatable w/a 3.3 HP. It will plane off with my 115 lb son in it (not with 220 lbs of yours truly). If I put a 6 HP on that, it would go like a bat out of hell (I put the 3.3 on because my 13 yr old son uses it). If you don't know anyone who can help, get a lightweight person to sit in it (foreward), just to see if it's a weight issue, but I doubt it is. Props? That COULD be the issue. It could have a power prop (low pitch) designed to push a small sailboat, but even that should get it to plane. Changing props would be about the last thing I would try. Don't bother with a speed prop. With that balance, it would just take too much "bite" and the energy would be converted improperly. Put the tilt on the middle adjustment. Good luck
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Nathan Shapiro
rick
I have the same dinghy that you have, and have an 8hp mercury on it. I also find in different times that i have trouble getting it to plane. Sometines i have to get my weight as far forward as i can. If i am going into the wind or against the tide/current, then i also have a problem. I realize that we have different engines, but i have tried the tilt at all the different positions, and find that tilt is best in the lowest position. Good luck
I have the same dinghy that you have, and have an 8hp mercury on it. I also find in different times that i have trouble getting it to plane. Sometines i have to get my weight as far forward as i can. If i am going into the wind or against the tide/current, then i also have a problem. I realize that we have different engines, but i have tried the tilt at all the different positions, and find that tilt is best in the lowest position. Good luck
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