9.9/15-hp 4-Stroke Outboard Motors?

[ranger58sb]

Originally Posted by ontno1

Have a Tohatsu 9.8 4 stroke on the same dinghy, a Walker Bay Genesis 310 FTD. I can plane with passengers and cargo of 500-600#. Passenger or passengers may have to move or lean toward the bow to get on plane, but once up, it stays up. I don't think I would want any additional horsepower.
Haven't had the occasion to work on it, so can't comment on service availablity in the Caribbean. I carry lots of spares.
To avoid the bad gas that can cripple a 4 stroke, I installed an in-line cartridge filter and haven't had any problems.

Thanks, that's a very useful data point, given you're running the same boat!

-Chris

[ranger58sb]

Kettlewell: Smaller jets, got it, that explains, thanks. Thought the jets on our current 2-strokes were as small as they get, guess not.

Ole: Thanks for that background; it helps. BTW, the Honda website says their 9.9 weighs 92-lbs, and the 15s/20s weigh 104-lbs. Also, no real place to buy "marine" (non-ethanol) gas around here; there are a couple gas stations (not necessarily fuel docks) rumored to be out on the coast somewhere, Ocean City maybe... but in any case, non-ethanol fuel is not really on option for us under normal conditions.

Bash: Haven't ever had an electric-start outboard before, so didn't know I could call it a "girl button" -- what a hoot!

All: I really appreciate the commentary, the more the better!

Are Hondas really quieter than Yamaha 4-strokes?

-Chris

[ranger58sb]

After more research on that fuel thing...

It looks like the Yamaha (and probably other brand) fuel pumps are mechanical/diaphram types -- i.e., not electric. I also see Yamaha sells a 10-micron fuel-water separator, which could presumably be hung on a transom and plumbed in-line from the tank.

Q: Is that fuel-water separator (or similar) the filter that folks are using with the small 4-stroke outboards?

Q: Are there any tricks or surprises with the plumbing? (I'm just thinking "easily removable" -- from the transom -- for service, etc.)

Q: How many users actually do mount an extra in-line filter?

Q: Is 10-micron dense enough? Or is something like 2-micron better?

Q: Do these fuel pumps create enough vacuum to work with the 10-micron filters? Could the fuel pumps even work with a denser filter (say, 2-micron)?

-Chris

[jeremiason]

Chris

We have been cruising the Pacific side of Mexico and Central America for almost two years now.

We carry a Yamaha 15 HP 4-Stroke on an Achilles 10'6" Rib with a three gallons gas tank. When we first bought the motor I downsized the prop 1" in pitch for fster plaining and lost about 4 miles per hour on the top end.

The down side to the engine is weight and making sure to run the carborator dry when not using the engine. When we first bought the engine in San Francisco, I did not run it dry or run it for about three months. The gasloine fouled the carbarator and we had to do a rebuild. Since then we have used fuel stabilizer (Available everywhere) an have not had the problem since.

We have found that the Yamaha Parts (Four Strokes) are available just about anywhere we looked in Mexico, El Salvador, Nicaragua, Costa Rica and here in Panama. We also found trainned and untrainned locals who could work on the engine if needed.

In fuel comparision with the 2-Stroke, you will notice about 35% decrease in fuel consuption using the 4-Stroke motor. For us that means we carry the three gallon on board tank and one five gallon jerry jug on our sailboat. With this amount of fuel we never want for gas.

This engine starts every time with one or two pulls, unlike the two strokes which can be pain to cold start.

Another nice feature with the Yamaha 15 HP Four Stroke is you do not have to run the engine to do a fresh water flush. It has a hose attachment built in. I flush the engine while it is store on our transome with our fresh water deck hose.

As far as filtering the fuel, we have not filtered fuel and have had no problems. Maybe the gods are watching out for us or maybe the engine isn't as tempramental as described in the previous posts.

In Costa Rica I did have a problem when the rainny season started. In about twenty minutes the rain completely filled my dighy. The fuel vent on the gas can was open and some water got in the tank. The engine died on the way back to the boat.

Using a Baja Filter, extracted the water from the fuel tank. Then I drained the carbarator, fuel lines and changed the spark plugs. The engine started right back up.

Reliablity, fuel economy and part avaiablilty world wide are the reasons I like this engine and would buy another.

[ranger58sb]

That's a very good recap, Tom, thanks very much!

Makes me wonder whether the need for an external filter is simply about the quality of the fuel supply... or supplier...

How often do you have to flush the engine? Here on the Chesapeake the brackish water seems to cut me some slack...

-Chris

[ranger58sb]

One of the other members in our Owners Club has recently commented he usually can't start is Yamaha 8-hp 4-stroke after about two weeks of non-use... whereas his 90-hp Yamaha 4-stroke starts first time/every time no matter how longs it's been sitting.

He's tried running the carb out of gas afterwards, filters, uses stabilizer, even has access to and uses non-ethanol gas... no joy.

Is that a common experience with the small 4-strokes?

-Chris

[Sailmonkey]

Originally Posted by ranger42c

Makes me wonder whether the need for an external filter is simply about the quality of the fuel supply... or supplier...


-Chris

My experience has been that any old filter will work fine if the engine is used all the time. I've got a small inline under the cowling of the 5hp 2stroke, it traps all the gunk that I don't want in the carb. The 2 stroke literally ate cup after cup of water without fail until it sat for several months....then all hell broke loose.

[jeremiason]

Originally Posted by ranger42c

One of the other members in our Owners Club has recently commented he usually can't start is Yamaha 8-hp 4-stroke after about two weeks of non-use... whereas his 90-hp Yamaha 4-stroke starts first time/every time no matter how longs it's been sitting.

He's tried running the carb out of gas afterwards, filters, uses stabilizer, even has access to and uses non-ethanol gas... no joy.

Is that a common experience with the small 4-strokes?

-Chris

It sounds like he is in the minority, based on my experiences and that of my fellow cruisers with Four Strokes.

Four-Strokes, although heavy are considerably reliable and start easily as long as they are maintained.

I would suggest he get it serviced and see if there is mechanical problem.

[Sailor Doug]

No one has mentioned closing gas tank vent. This took my Yamaha 4 4stroke with stabilizer to always starting second pull. I am not recommending this engine they must of used a lot of trainees to design. ( poor design) but that is another story.
I am curious if any one has taken actual gps speeds with their motor/engine styles. I have a new 10'6" soft bottom with big end tubes. I would like some qualitative information on how much speed I would get with a 8, 9.9 or 15 HP 4 stroke. Currently I get 7 knots (on plane) with just me on board. Does more HP mean slightly more speed with two up but top speed is limited by stability with one person at less than 10 knots?

[colemj]

Our 350lb RIB powered by an older Honda 15 4-stroke with just me on board does 20kts WOT.

Closing the tank vent does help prevent water ingress, but if you live where the sun is hot, you will end up with a beach ball for a tank if you forget to open it every morning and after every rain. Better to invert a small can or bowl over the fill cap.

Mark

[ranger58sb]

Originally Posted by jeremiason

It sounds like he is in the minority, based on my experiences and that of my fellow cruisers with Four Strokes.

Four-Strokes, although heavy are considerably reliable and start easily as long as they are maintained.

I would suggest he get it serviced and see if there is mechanical problem.

Says he's had it to the Yamaha shop several times... and they apparently say it's always the carb needs cleaning, everything else good to go. Apparently it's usually a gumming problem, which apparently wasn't affected one way or the other by either a 10- or 2-micron in-line filter...

Useful to hear it's maybe just a one-off anomaly...

-Chris

[jeremiason]

Originally Posted by ranger42c

Says he's had it to the Yamaha shop several times... and they apparently say it's always the carb needs cleaning, everything else good to go. Apparently it's usually a gumming problem, which apparently wasn't affected one way or the other by either a 10- or 2-micron in-line filter...

Useful to hear it's maybe just a one-off anomaly...

-Chris

Like I said in my first post that happened to me once when I didn't run the engine dry of fuel before storing it. Since I started doing that and using fuel stabilizer, I haven't had a problem in four years.

I know you said he also runs it dry and uses fuel stabilizer, so I have no idea why his carberator would be gummed up, unless maybe he forgets from time to time?

[ranger58sb]

Originally Posted by jeremiason

Like I said in my first post that happened to me once when I didn't run the engine dry of fuel before storing it. Since I started doing that and using fuel stabilizer, I haven't had a problem in four years.

I know you said he also runs it dry and uses fuel stabilizer, so I have no idea why his carberator would be gummed up, unless maybe he forgets from time to time?

Good to know yours has been trouble free.

Yeah; I only know what he said....

I suppose there could be a difference between the carb (and probably the fuel pump) on the 8.8 and the one you have on the 15... I haven't looked closely at the Yamaha parts lists to compare...

-Chris

[Gordon]

Has anyone experience with the new Suzuki 4 strokes?
Global News News.2012 | Global Suzuki

[ranger58sb]

Originally Posted by Gordon

Has anyone experience with the new Suzuki 4 strokes?
Global News News.2012 | Global Suzuki

Had not seen that, thanks for the heads-up and the link.

When I last compiled comparative stats, the Suzuki website still only listed the carbureted DF15 motor, 105 lbs... and if you go to the "Marine" tab, that still the one they list now, no other mention of the DF15A that I can find.

I'm actually Suzuki-friendly, since I rode one of their bikes in the early '80s, and we had one of their little Jeep-like things in the mid-'80s when we lived in Europe... But I don't find an easy way to assess their marine dealer/servce network on their site...

-Chris