9.9 hp on 10' inflatible

[dMAC]

I am looking to replace my 20 hp Yamaha four stroke on my 10' rigid inflatible witha 9.9 hp Mercury. I want to hear from anyone that has experience with the 9.9 and specifically whether it has enough power to bring two average people up to a plane. Thanks.

[Captain Bill]

It will, but just barely. If you are carrying any cargo as well it might not. It also depends on how much your rib weighs. If it's heavy it might not do it at all.

[Paperbird]

Originally Posted by Captain Bill

It will, but just barely. If you are carrying any cargo as well it might not. It also depends on how much your rib weighs. If it's heavy it might not do it at all.

We have a 9.8 tohatsu with fins on our 10.2' zodiac (single floor model). It planes great with 2 of us along with a normal load of groceries or snorkeling gear, etc. Won't quite make with 4 people. Also wont plane when we make a major fuel and water resupply run.

But we like the combination. A little easier for us to handle and works well in most situations. But def a compromise


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[Robin3]

We have a 9.9 Mercury 4 stroke on our west marine Hypalon 310 RIB ( single floor model) and this was the optimum combo according to West when we bought it, It planes just fine with 2 up ( all up 400lbs 'ish) but I cannot say if it would with 2 up and also a heavy load on board.

[svadagio]

Had a Mercury 9.9 2 stroke on a 10' Caribe. Had fins. Fins really help. It would plan with two of us and a small amount of stuff. Wife would get up on the bow to get it up. I am heavy though.
Bob

[undercutter]

Don't do it!!!! I did and regretted it big time. Not only will it not get the boat up with any kind of load but if you come from a place with ethanol fuel you will have nothing but problems with the low speed jet varnishing up even if you do run it dry every time you use it. It was one of the worst purchases I ever made.

A good option might be the Honda 20hp which is the same as the 15 except for carburation which gives it the extra umph. Both of these are very light motors which are easier to handle.

Personally, I went back to the Yamaha 20hp 4 stroke but we have electric winches so pulling the boat up onto the davits is easy for the wife and I. Once you can put 4 in the boat with a load of groceries, fuel, etc and still plane you will never be happy with less.

Just my opinion.

[monte]

Really happy with our highfield ultralight 310 (45kg) and Johnson 2 stroke 9.9 (36 kg)
Planes easily with 3 adults (220kg), not so easily but sometimes with 4 adults. Planing speeds around 17K. Easy to drag up on the beach alone. Easy to lift on the davits without using a winch.

[exMaggieDrum]

We always planed with our 9.9 Tohatsu 4-stroke. Fins highly recommended. And the weight in the dink must be positioned as far forward as possible, including the operator. And you need to adjust the motor tilt correctly. It won't plane if you sit right at the stern. I believe the type of dink bottom matters too, as does the buoyancy (tube size, PSI). You want the bottom to be as streamlined as possible and not "bend" from the bow to the middle (if under-inflated say). We were very happy with ours but go faster people may want more HP. We zipped along as fast as we wanted. Wave conditions matter too. It was nice having the lighter weight motor, both to get it on to the boat when needed, and pulling up on the beaches in Mexico.

[RichandHelen]

We have a Merc 9.9 4-stroke on a 10' AB RIB. Goes like a banshee with the two of us. You'll still need a tiller extension to go up on plane solo. Have yet to put such a load in it that it wouldn't plane. I'm 170, the wife about 130. It's a pain to pull the 9.9 for service. I wouldn't want anything heavier for that reason.

[Dave the Canuck]

We have the Merc 9.9 2-stroke. Extremely dependable and more than enough to bring the two of us up on plane. Has yet to need more than three pulls. As per the earlier post, put the fins on and getting on plane will be even easier. Crew will need to be forward.

[Robin3]

pretty darn difficult to buy a 2 stroke nowadays as the econuts seem to have ranked them as devil's toys?

[Dave the Canuck]

9.9hp Mercury Outboard Boat Motor For Sale

[Cheechako]

Many 15hp are same weight as the 9.9. a 15 on a heavy double floor rib will plane with 4 people aboard. Not huge people!
Had find, didn't like them and took them off. We found, if heavy loaded, just as the boat is trying to get upon plane, the forward people/person shifts weight forward and up the boat pops onto plane.

[Bulawayo]

We use an all aluminium 'semi-rigid' dinghy which is 3.4 meters, a full deep vee hull and around 120kg. We use a Yamaha 25hp Enduro two stroke with fins and we plane with six of us. Im a svelte 260lb (but 6ft6in), my wife is 140lb and my kids are all large as well. We get on the plane with all six of knowing where to sit. We also have a 5hp two stroke. Yam two strokes are great buys in some places - we bought ours brand new last year. Our kids use a 2.6m all aliminium dinghy with either a Yam 15hp Enduro or their put-put Yamaha Malta. The four of them can plane with the 15hp. Personally, I really believe a 15hp is the minimum for general use and for safety.

[mserafi1]

I did a bit of research on all the makes of 9.9 4 strokes a few years back when I moved the outboard from the well to a transom mount on my Columbia 26 Mk 2. The impression I got after reading the manufacturer's information was that these were developed as kicker motors for fishing boats that troll for long periods of time. Lots of torque and power, which also served well as a small sailboat engine. This, imho, is not what you would want for a rib. I would think more along the lines of a light weight 15 or 20 2 stroke with oil injection for clean burning.

Good luck.