Dinghy engine techniques

Since the advent of ethanol in our gasoline, there have been horror stories about how they affect our dinghy engines. I have had the pleausre of experiencing some of those stories. Two times in 3 years I have had to rebuild the carburetor on my newish Yamaha 2 stroke.

Well this last time I took it to the dealer and he mentioned something to me that nobody had ever told me. It is common practice for us to run the gas out of our carbs when we are done using it. He said that while this was the way to do things before the ethanol debacle, it is not advised anymore. When you run the fuel out until the engine quits, there is still a little fuel left on the bottom of the bowl along with the water that the ethanol likes to attach itself to. Well the fuel will evntually evaporate and leave nothing but the corrosive water. Then you end up with the needle in the bowl getting fouled up with crap and sticking!!! I do not run my carburetor "dry" anymore and so far, this season, I have had no issues with the dinghy engine. I have had sit times for the dinghy of over 2 months...no issues with untreated gas.

There are times when I am around friends/people while they brag about not having any ethanol issues with their dinghy engines....I ask them if they pull the fuel line to burn the gas out of their motor....the answer is a resounding...NO!!! Not a scientific survey but it has backed up this line of thinking.

So for those that have ethanol issues with their dinghy engines, do you pull the fuel line and burn the gas out of your carb? And are there people out there that do not and what is your experience ref ethanol issues???

Yes, we run all our outboards, 2 and 4 cycle, out of fuel whenever they are not going to be used again for a week or more. However, we do not burn ethanol gas in any of them. We get non-ethanol fuel from the farm grange near us. Once we started doing this all our issues with hard starting disappeared.

If an outboard (or lawn mower or power washer or generator) are going to be laid up for a season we also drain the carburetor bowl(s), remove the spark plug(s), spray WD40 into the cylinder(s), turn the engine over by hand a few times and replace the spark plug(s).

Running an outboard out of fuel before a period of non-use is the process recommended by the big Yamaha/Grady-White dealer in this area, particularly if one uses ethanol fuel.

All I've done, and I do it every time, is add Stabil to the fuel every time I buy fuel. So the fuel is "preserved" all the time. I'll probably jinx myself by saying it, but I have never had an engine not start right up, including things that have been sitting for a year or more. This includes outboards, lawn mowers, chain saws, cars, etc. I've just never had a problem, and don't think its because I'm lucky.

twistedtree said:

All I've done, and I do it every time, is add Stabil to the fuel every time I buy fuel. So the fuel is "preserved" all the time. I'll probably jinx myself by saying it, but I have never had an engine not start right up, including things that have been sitting for a year or more. This includes outboards, lawn mowers, chain saws, cars, etc. I've just never had a problem, and don't think its because I'm lucky.

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So you are saying that you do NOT run your carb out of gas???...just to clarify

Marin said:

Running an outboard out of fuel before a period of non-use is the process recommended by the big Yamaha/Grady-White dealer in this area, particularly if one uses ethanol fuel.

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Marin, I am not going to argue with you about NON ethanol fuel. But I will argue your last sentence and say that the BIG Yamaha dealer here says that you should NOT run it out of fuel if you are using ethanol fuel. I have personal(if non scientific) evidence to prove it. I also have the logic of the dealer to back it up. Can you refute his logic? Because it goes completely against what you are saying.

Twisted, I have used every fuel treatmetn under the sun to no avail. I do not think you are lucky. And I do not think it is because you use fuel treatment. I think it is because you do not run your engine out of gas.

And this is how "most" of my ethanol issues have gone(and this is with a Merc 15hp and a Yamaha 15 both 2 stroke). It isn't normally a "hard starting" issue. Engine starts right up....runs fine. You putter around and then get on it up on plane. It is when you close the throttle that the float sticks and the engine floods. You go from humming along with a wonderfully running engine to an engine that completely goes dead and you go coasting down to nothingness. And THEN it is hard to start. Once you let it sit(or pull on the starter enough to clear the carb of excess fuel), then it will start up and the cycle will continue.

Other times...the engine starts right up like it should and then goes....bwhooooooop bwhoooooop bwhoooop bwhoop BWHOP!!!! ANd dies and is then hard to start because it floods(float stuck).

If I don't use the dink for a week or so, I have to use the little bulb in-line primer to full the lines and I assume, the carb. So while I don't run it dry intentionally, I think it may end up dry due to evaporation anyway....

Easy, use the dinghy more often. Pretty much all the gasoline I burn in my dinghy outboard (2 stroke Yamaha 15) is E10. I don't use any additives, but I do use the outboard at least once every couple weeks. If it's going to sit for more than a couple weeks (very rare), I run the carb dry. No problems so far.

Baker said:

So you are saying that you do NOT run your carb out of gas???...just to clarify

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Thats right. I shut off the machine and walk away. Just the other day I pulled out a chain saw that hadn't been used for at least a year. It started right up after 4 or 5 pulls.

Thanks, Baker, that's good advice, it is getting my antique Honda too; explains the hard-start.

dimer2 said:

If I don't use the dink for a week or so, I have to use the little bulb in-line primer to full the lines and I assume, the carb. So while I don't run it dry intentionally, I think it may end up dry due to evaporation anyway....

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Some evaporation, yes, but likely just the settling of fuel away from where it is supposed to be to support combustion. That is why they call it "priming"....to get it where it needs to be and not where it wants(settling/gravity)) to be.

twistedtree said:

Thats right. I shut off the machine and walk away. Just the other day I pulled out a chain saw that hadn't been used for at least a year. It started right up after 4 or 5 pulls.

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All of my 2 stroke yard "implements"(blower and weedeater) work just fine after sitting for a season. In fact they are 10 years old and still work fine while sitting for 5 months a year. There is no easy way to run them out of gas.

Baker said:

I also have the logic of the dealer to back it up. Can you refute his logic? Because it goes completely against what you are saying.

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No. However, before we switched to non-ethanol fuel we used the Yamaha dealer's advice and ran the engines out of fuel as I described before. Once we started doing that all our hard starting problems went away.

When I would pull the carburetor drain plugs after running the engines out of fuel and the engines were going to be laid up for awhile, perhaps two little drops of fuel would come out. That's it. So while your dealer's logic is perfectly sound, in our experience with our engines anyway, there's not enough fuel left in the bowl for his reasoning to be an issue.

All the posts above is the main reason why I don't want a dinghy. Keeping my 42 OA and its 440 Yanmars healthy is all the engine maintenance I want!

I switched to propane and plan to avoid small gasoline engines when ever I can.

While not having a dinghy at all certainly eliminates outboard problems, in this area it also eliminates the ability to use your boat unless all one wants to do is simply marina hop and never anchor or moor out. And since the best places to go along this coast are the places where marinas and harbors aren't, a dinghy/shoreboat/tender of some sort becomes almost essential. Particularly if one lijes to go ashore, explore, crab, fish, etc. To us, anyway, boating up here without a dinghy would be very boring boating indeed.

In places like southern California where it sounds like marina hopping is pretty the only option, a dinghy is perhaps not actually needed by most boaters.

One thing that has really helped me, is that I no longer use fuel that is more than a month or so old in the dinghy. If I know it is going to sit for a while I just pour the dinghy fuel from the tank into my truck.

I only use non ethanol fuel and I don't drain run the carb dry at my dealers instructions. 20 hp Suzuki 4 stroke.

Dougcole said:

One thing that has really helped me, is that I no longer use fuel that is more than a month or so old in the dinghy. If I know it is going to sit for a while I just pour the dinghy fuel from the tank into my truck.

I only use non ethanol fuel and I don't drain run the carb dry at my dealers instructions. 20 hp Suzuki 4 stroke.

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Thanks for the input, Doug. Another non drainer!! (Although dumping the tank does not directly impact what is going on in the carb...non ethanol fuel also).

Marin said:

While not having a dinghy at all certainly eliminates outboard problems, in this area it also eliminates the ability to use your boat unless all one wants to do is simply marina hop and never anchor or moor out. And since the best places to go along this coast are the places where marinas and harbors aren't, a dinghy/shoreboat/tender of some sort becomes almost essential. Particularly if one lijes to go ashore, explore, crab, fish, etc. To us, anyway, boating up here without a dinghy would be very boring boating indeed.

In places like southern California where it sounds like marina hopping is pretty the only option, a dinghy is perhaps not actually needed by most boaters.

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In full agreement, Marin. To me, being on the hook gives me a great sense of freedom. But let's not make this thread about WHY you need/want a dinghy.....

We have 2-2 strokes and run the fuel out if we're not using them for a few weeks or more. The only carburetor I have rebuilt was the one that I didn't run out. The gas partially evaporated in the bowl and left a varnish type residue there and in the jets. Our 15 hp Yamaha 2 stroke we used daily for 6-10 months per year for 6 years. That carburetor has never been taken apart. We do try to get ethanol free gas.

Non-ethanol fuel solves all sorts of problems. I think and from what we've been told by fuel people, not using fuel that's a month old or more is an unnecessary precaution. Ethanol is the source of many problems, not the least of which is the separation John speaks of.

According to our local fuel "experts" ethanol defeats the value of adding Stabil, at least the normal Stabil. There may be a version that is formulated for ethanol fuel now, I don't know.

But non-ethanol fuel is said to be good for a year or more. We have non-ethanol fuel in our Honda generator at home that sits for the better part of a year yet the motor starts instantly on the first pull every time. We do shut off the fuel and run the carburetor dry after we use it to avoid potential gumming up problems in the jet(s) although I don't know if we'd have any with non-ethanol fuel. We do not use a stabilizing additive.

If we had to use ethanol fuel then we would do as Doug describes and not use fuel more than a month or two old in our outboards, mower, etc.

The people I know with outboards and other similar type motors all run them dry after use. They say it's why they no longer have starting problems after a period of non-use. So far as I know, most or all of them are using E10 fuel in their motors.

I suspect the reality is that if an outboard is used relatively frequently running them dry accomplishes little or nothing no matter what type of fuel is used. But if the motor is going to sit for awile-- a month or more maybe and certainly for an entire season, then getting all the fuel out of the system becomes a lot more important, even more so wirh ethanol fuel. Which is why we drain the bowls, not just run the motor with the fuel shut off or disconnected until it stops

Ever since I started using this additive all my small engine issues have just disappeared....

Mechanic In a Bottle | B3C Fuel Solutions

Available on Amazon..

This is the stuff my Yamaha dealer recommended....

And I do have to say another thing....My Yamaha dealer said, ideally, he would drain it halfway(15-20 seconds maybe). I do not remember his reasoning on it. I have a call into him right now and waiting on his call so I can get his reasoning on that. But he did say if he had to choose from running it "dry" or just leaving the fuel in it, he would leave the fuel in it.

I hate small gas outboard engines. I went to using an electric outboard on my RIB. I don't go fast, but I never have to keep gasoline on board anymore and it recharges with a solar panel, 12v, or 110. Also super lightweight.

I can speak from experience what happens to ethanol fuel when you don't use stabilizer and don't run the carbs empty. In about six months, the gas turns to a gel that resembles Vasoline mixed with flour that takes many cleanings to finally get the tiny clumps of particulate out of the system. It hides out everywhere! So now any gas engine that is not used or refueled at least weekly, gets stabilized immediately.
My 2 stroke dinghy engine gets the fuel bowl run empty at the end of every cruise.

I have a 2hp Honda 4-stroke and a Merc 15hp 2-stroke. I run the bowls dry at the end of a trip before storing the motors onboard. The precise reason for doing this is that I was advised to do it and I've always followed that advice. I have no experience letting them sit with fuel in the bowls.

But one thing I do is buy the high octane gasoline (yes, it has a 10% ethanol blend) so as the fuel ages and the octane drops, it is still high enough octane at the end of the season. Now that I read this thread, I'm realizing that I failed to put the Stabil in the tanks when I refueled them a couple of months ago. I guess it's not too late...

At the end of the cruising season in Oct or Nov, I typically pour much of the remaining fuel into my car tank and resupply in the spring.

Dougcole said:

One thing that has really helped me, is that I no longer use fuel that is more than a month or so old in the dinghy. If I know it is going to sit for a while I just pour the dinghy fuel from the tank into my truck.

I only use non ethanol fuel and I don't drain run the carb dry at my dealers instructions. 20 hp Suzuki 4 stroke.

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Ditto, sorta. But first, assuming your Suzuki is one of the newer ones, it's a) fuel-injected, and b) two cylinder. Both might be important distinctions.

Back to the regime. We can only get ethanol, so we've had to adjust our plan to that. Our one-cylinder two-stroke 5-hp Johnson (Suzuki) was susceptible to ethanol issues. Using the motor often, no problem at all.

But for longer period of disuse... No brand of stabilizer (including both types of Stabil) ever did squat. I usually let it run dry after use, but seemed to find no big difference between doing that and doing nothing. (I have more recently heard the theory about not running the carb dry, though, and would think there could be some factoid behind that. Certainly when gas dries, it can leave a kind of varnish... In any case, II noticed no particular difference.)


Anyway, we eventually started siphoning out any remaining gas after 3 weeks of non-use. Period. That pretty much ended the problems.

Starting over with fresh (ethanol) gas seems to work pretty well. Even if a little of the old remains in the onboard tank or in the external tank, that seems to become diluted enough with new gas so the carb and the one-cylinder motor can deal with it.

With our newer 15-hp Suzuki fuel-injected two-cylinder 4-stroke... so far no problems. But I've still been sticking to the recycle routine out of habit, so not sure I can say the fuel injection or the two cylinder might be part of the solution or not.

I do remember back 60 years ago or so, we never worried about the gas in our outboards. Didn't matter if it was a year old or more, didn't matter if the motor hadn't been used in 6 months or whatever, it'd start and it'd run.

Now? Not so much. At least with the smaller carbureted motors.

-Chris

FlyWright said:

At the end of the cruising season in Oct or Nov, I typically pour much of the remaining fuel into my car tank and resupply in the spring.

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You would probably do better to pour that into your boat diesel tank. I wouldn't want that crap going through my car's fuel system. In your boat, it is better filtered and you have bigger tanks for dilution.

Marin is right, since I use non ethanol fuel it is probably overkill to drain my tanks before any sort of extended storage. But it is easy and cheap, so I do it rather than worry about bad fuel.