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dMAC · 24-11-2014, 16:29

My yahama 20 hp four stroke is really fickle. If i don't run it after a few weeks the carburator fouls. What is the most dependable way to power my 11' zodiac? I am thinking about finding a two stroke merc.

Also would a 9.9 hp provide enough power to get two people up on plane?

Magnawake · 24-11-2014, 17:09

My Yanaha 100 hp (not on my dinghy) was hard starting as well. I started using non-ethanol gas and stabil fuel treatment. The kind in the red bottle. It took care of the problem. My ski boat would sit up all winter long and start right up too. Its a great product. I learned of this trick from a person that was a supervisor at Exxon Chemical plant years ago.

Oh yeah my 9.5 hp doesnt plane with 2 people. Both of us are kinda on the heavy side.

Vasco · 24-11-2014, 17:13

If you can get a 15hp Yamaha 2 stroke. It'll get you up on plane. Don't know your location but if you're on the east coast it's worth a trip to Nassau.

ranger58sb · 25-11-2014, 04:48

Quote:

Originally Posted by dMAC

If i don't run it after a few weeks the carburator fouls.

As a work-around, when we had similar problems with our older (2-stroke) outboard... mostly caused by ethanol gas, in our case.

When finished with it, I generally ran the engine until the carb ran out of gas... then drained the fuel hose back into the external tank...

And I began draining/recycling unused gas from the external tank at about the 3-week mark, replaced with fresh gas for the outboard.

Problem mostly solved.

The gas was always stabilized, too, but I didn't find those products to be any kind of magic bullet.

-Chris

**a64pilot** · 25-11-2014, 05:46

Seemingly on here 99% of all outboard problems posted are carburetor, presumably from alcohol in the fuel, although I have always had good luck for years with Sta-Bil, many have not, so it's apparently not the solution.

I'm trying something new, it's the new 20 HP Suzuki fuel injected engine, currently sitting on my dink on it's trailer in my back yard. I stopped using it two months ago and did nothing to preserve it, just stopped using it, the fuel in it's tank is currently three months old, I figure in another four or five months when the weather warms up, I'll dump the gas in the tank and try to start her up, fuel in the engine will be six months or so old.
I theorize that the fuel is in an enclosed system with no exposure to air and all will be OK, if I'm wrong, then I guess I'll learn how to de-varnish a fuel injection system

I believe the only real solution is to eliminate the carburetor (fuel injection) or eliminate the gas (Propane).

Funny though how some seem to have severe problems with fuel and others dont?

colemj · 25-11-2014, 06:09

Quote:

Originally Posted by a64pilot

Seemingly on here 99% of all outboard problems posted are carburetor, presumably from alcohol in the fuel, although I have always had good luck for years with Sta-Bil, many have not, so it's apparently not the solution.

I'm trying something new, it's the new 20 HP Suzuki fuel injected engine, currently sitting on my dink on it's trailer in my back yard. I stopped using it two months ago and did nothing to preserve it, just stopped using it, the fuel in it's tank is currently three months old, I figure in another four or five months when the weather warms up, I'll dump the gas in the tank and try to start her up, fuel in the engine will be six months or so old.
I theorize that the fuel is in an enclosed system with no exposure to air and all will be OK, if I'm wrong, then I guess I'll learn how to de-varnish a fuel injection system

I believe the only real solution is to eliminate the carburetor (fuel injection) or eliminate the gas (Propane).

Funny though how some seem to have severe problems with fuel and others dont?

We let our Suzuki EFI outboard sit 6 months with nothing done to it between the time we last shut it down and restarting it - gas left in tank and all outside exposed to the tropical environment. It started immediately and ran with no problems. We then let it sit another 3 months in the same environment and it again started immediately and has been running great.

I sound like a broken record on this, but here goes again - everyone should have an external fuel filter/water separator on their outboard. I see many, many outboard carburetor issues out here cruising and there is one single clear-cut outstanding commonality among them - those that have filters/water separators are not having carb issues, while none of the outboards with carb issues have an external fuel filter/water separator.

Mark

HopCar · 25-11-2014, 06:46

I got tired of fighting carburetor problems and switched to propane. I have a 2.5 Lehr for my dinghy and just bought a Lehr 15 for the skiff I'm building.

The 15 is electric start with a small Lithium Iron battery under the hood. It's a very cool set up.

My rule of thumb for picking an engine size is to put no less than about 65% of the maximum rated horsepower on a planing boat. Bigger would be better.

Randyonr3 · 25-11-2014, 07:00

Had major issues with a 9.9 I had purchased new.. Had it back in the shop a number of times as it would "go out of adjustment" within a couple hours of running it..
Was told it was due to the "EPA" standards set on the motorand he was kept to the standards in repair.
BUT, the guy at the shop where I bought it gave me a list of parts and said that if I came to him and asked him to to install these parts in the motor, it would no longer need his assistance.
I did, and He did, and I didnt have any further issues..
If you have a new 4 stroke having problems staying in tune, it can be fixed, its not legal but it can be done..