2.5hp Dingy Speed?

[CAELESTIS]

I am buying a used 2.5hp Mercury 2-stroke as an additional dinghy motor. Can someone tell me the approximate speed on a 10ft RIB?

[k9medic]

I ran a 4hp Suzuki on a 10ft. West Marine dink for a while. With just me in it I could get about 4kts at WOT. With my wife and two small boys we almost didn't make any headway against an outgoing tide.

I now have a 9.9 and can plane the dink with three people and push water at about 6kts. with 4 people.

Point being - you will be lucky to see 2-3 kts.

[CAELESTIS]

Thanks! I also have a 9.8 Tohatsu that a GPS says 23mph at WOT with just me.

Wanted a lighter motor to putt around the marina.

[Stu Jackson]

Originally Posted by CAELESTIS

Wanted a lighter motor to putt around the marina.

Great idea. I still kick myself for selling our old 1.2hp Johnson "egg beater" single gear outboard. We now have a 9.9 hp Evinrude 2 stroke for our 10'-2" Zodiac.

[Cuttyhunk]

I would guess my 4 stroke Honda 2.3 does about 3 knots around the (very protected) harbor when I give it full throttle. Zoom! 28 lbs, can't beat it. (And yes, we have an 8 horse, too, but the Honda is so much easier to deal with.)

[Neo]

I have a 2hp, 2 stroke yamaha on my 8 foot fiberglass dinghy. With a clean bottom I could do about 3 knots solo at 3/4 throttle. It was perfect for the mooring field but not much else. On an 10 foot rib with two people it would be about the same, I would guess. Very light, easy to start and I can lift it off the dink and put it on our boat's stern rail with one hand. I love it.

Oh, it is also very noisy compared to a four stroke.

[k9medic]

I love my 9.9 four stroke. It starts on the first or second pull, and is so quiet I have to look at the discharge stream to make sure it's running. I've been running on the same 3 gallons of gas since July.

Right now my boys (9 and 8y/o) idle around the bay with it and have a blast

Like yours I can run about 23kts. on the GPS by myself.

[Sailmonkey]

Our 2hp/2strk mariner on an 8'6" rib will push us to roughly 3-4knots full throttle.


Sent from my iPhone using Cruisers Sailing Forum

[sailorboy1]

I'm impressed there are so many with knotmeters on their dinghy.

I don't know how fast I could go with my old 2 HP Honda, but with 2 people against a 10 knot wind and 1 foot waves it was a crawl.

[monte]

dinghy knotmeter = taking your iphone and using navionics. Cant help with the 2.5 but our 3.1m rib with 10hp johnson 2 stroke does 17K WOT with 2 adults

[CSY Man]

10.3 feet inflatable floor (and keel) Mercury dink, 4 hp, 4 stroke Yamaha, 10,9 knots with this 220 lbs stud onboard. Needed extended handle and leaned well forward to get it on the plane, but the rig just outperformed my expectations for sure. Previous motor, 4 hp Evinrude 2 stroke, same dink, 6-7 knots on a good day.
No idea why one 4 hp engine is so much faster than another 4 hp...?