posted 08-28-2011 09:04 PM ET (US)            

Thoughts?

posted 08-29-2011 01:18 PM ET (US)            

As sosmerc also pointed out, the running-dry procedure most often doesn't actually run all of the fuel out from the carburetor so that gumming of the lower positioned orifices and passageways often will still occur (sometimes it even encourages this problem). What does happen is the level in the float bowl simply becomes too low to be pulled up by the idle circuit with sufficient volume to maintain the necessary mixture to run - the mixture becomes way too lean to run the engine. Also way too lean to leave a good protective coating of oil on the internal parts.

posted 08-30-2011 02:15 PM ET (US)            

Saying that running a 2 stroke (premix) till it stops isn't harmfull is like saying so and so lived to 90 and smoked so it can't be that bad.

When owners manuals say to run out of fuel they are thinking it's end of season and you are going to fog out as it's running out of fuel.

Sure people do it and get by but there has to be some extra wear in addition to leaving the motor prone to rusting internally from condensation. Also, some people don't keep their motors long enough to see the effects.

posted 08-30-2011 04:42 PM ET (US)         

It says to not do this will leave varnish and jet clogging as the fuel eventually evaporated from the carb bowls. They also say to do it if you are planning to tilt the engine up to avoid spills. None of this is related to storage fogging.

For oil injected engines, they say NOT to run out the fuel, as you will load up the carbs with oil. That is why most of those engines have permanent fuel lines, with no disconnects at the engine.

posted 08-31-2011 12:12 PM ET (US)            

Also, I remember pointing out that old Mercury run-dry recommendation once way back when to our roving factory service representative. I recall him saying then that that recommendation was being dropped or going to be dropped. I'd be interested to hear if any of you Mercury classic 2 stroke owners with slightly later model years still have this recommendation in your owners' manuals. I have a gut feeling as the 80's wore on to the early 90's we might see this recommendation disappearing. Maybe sosmerc has better first-hand knowledge of this.

posted 08-31-2011 09:21 PM ET (US)            

Once there is insufficient fuel in the combustion chamber to run, the engine obviously stops running and starts its coasting phase to its ultimate stopping point. With each rotation while coasting with little to no new fuel/oil, a fresh, essentially gas-free and lubricant-free volume of air is still pulled into the crankcase, swirled around the bearing surfaces and then pushed up to the top of the cylinder (combustion chamber). This lubricant-free air movement will without doubt remove at least some of the lubrication from those bearing surfaces and cylinder walls that was present when you were supplying the fuel and oil at the operating volume.

posted 08-31-2011 09:36 PM ET (US)            

On my 1985 Yamaha 225 on my Revenge, I've never done it, don't ask me why.....but almost every time I go back to the boat, which genberally is storred with the motor up, I'm constantly cleaning up the residual gas/oil that's dripped out of the carbs, and run down into the splash well.....I think the Yamaha is trying to tell me something.

posted 09-01-2011 07:35 AM ET (US)            

After every use (end of day), I shut off the fuel, and let it run completely out. Firmly close the vent cap on the internal tank and store.
It is frequently transported on it's side (per manual) and when it is set on the transon, fuel open, vent open and choked, it starts on first or second pull.
For winter storage, the manual suggests to open the fuel drain screw, and completely drain fuel from the internal tank. I did it the first year, but have not done it in recent years. With treated fuel, there has been no problem.

The main reason I run it out of fuel after each use is that I want 0 fuel dripping anywhere/anytime. It works
great.
In additon, I have a dedicated 1 gallon plastic tank with the new EPA valve that seals off upon release. These portable tanks are good for filling the Honda tank with no spillage, even when bobbing up and down in the water. We can carry that portable tank in the inflatable and spend hours on the inflatable. I think a gallon of gasoline will run that 2hp Honda around the world at the equator about six times. :>)

posted 09-01-2011 09:59 PM ET (US)            

I wasn't picking you out specifically. I was intending to paint a "composite" word picture, a generalization if you will. I was most assuredly not singling you out.

posted 09-02-2011 01:13 PM ET (US)            

To run dry or not to run dry is a simple matter of choice that in the end, may or may not have easily quantifiable consequences for any given operator. If carb leakage when tilted is a significant problem and annoyance for a given user, then running dry might have value to them.

For me, since there is absolutely nothing to be gained by the running-dry practice (no leakage problems), the choice is obvious. Leaving more oil (and fuel) coating the lower and upper end of the engine CAN'T possibly do harm to the engine between runs. Certainly it can't be more detrimental (or less helpful ?) than running it as low on lubricant as possible. Without a doubt, running an engine out of gas can actually accelerate carb gumming problems. Years in the outboard repair industry have taught me this.

Specific to your EFI Suzuki Nick... I would never run that engine low on fuel. Not because the internals will suffer - you obviously know that is not the case since it is a 4-stroke with an independent oil supply - but because you never want to allow your electric fuel pump to run in anything but a solidly fuel environment. Sounds like your technique bumps up against that. You also want to keep the fuel rail air free of course. Certainly no good reason not too.

posted 09-02-2011 02:12 PM ET (US)            

Tim is already implying that there are pro's and cons to both methods.

My take now is that, especially amongst the Whalers owners on this forum, most boaters do not keep a motor anywhere NEARLY as long as the motor is capable of running. Therefore, the slow accelerated wear you would get from running it dry may never affect the typical Whaler owner, who will have long since replaced his old motor. Tim ribbed Larry to that effect, where he jabbed that Larrys old towers might only last 3000 hours instead of 6000 because he runs them dry. There may be a whole lot more truth to that jab than we give credit for. I'm the type to keep a motor for the long haul... as long as it is the type of motor that can be fixed by the average mechanic, with average tools.

posted 09-02-2011 03:23 PM ET (US)         

My experience with 20ish years of running motors out of fuel and 7ish years of leaving the carb bowls filled with treated fuel is that I have far less problems getting stuff running after extended storage when I do not run the fuel system dry.

Two stoke or four everything starts right up in the spring/winter.

This is especially evident on the garden tiller which is used twice a year. I can rebuild that carb in five minutes with my eyes closed because I've done it so many times. It was actually seeing the residue left in the bowl and on the jets in the tiller that really caused me to change my methods.

Add some seafoam to your fuel and run it through the carbs and you are good to go.

posted 09-02-2011 04:25 PM ET (US)            

That's interesting Nick regarding your experience with stale gas causing electric fuel pumps to go bad. I've been working as a mechanic off and on now for decades and I don't think I've ever come across a bad electric fuel pump that anyone (me, other mechanics, or any service reps) could or have attributed to stale gas. I've certainly replaced loads of bad electric pumps. Soooooo many iterations of them for Mercruiser engines! Essentially all internal electrical failures with the motors (which have remained properly sealed from the pump). Many failures do to overheating (lack of fuel). I suppose stale gas is a possible cause but without air in the system it would take an extremely long time for the gas to deteriorate to the point of varnishing or getting gummy enough to bind a pump or its associated valves and/or passageways.

posted 09-02-2011 11:22 PM ET (US)            

Here is how the climate works in Central Florida.

From December thru Feb. it is damn cold, anywhere between 20 to 50 degrees, on these days only snowbirds take their boats out. In March the wind blows constantly about 25+ mph everyday, but the temperature is about 70 degrees. Only snowbirds and tourists take their boats out, some never return, remember the pro football players that drowned, 3/01/10. April and May the boating weather is pretty good around here. June thru Sept. the weather is pretty hot, about 95 degrees out on the gulf and nary a breeze to cool you off. And every afternoon the thunderstorms move in about 3pm. Don't want to around them for sure. Only the tourists take their boats out and bake in the sun all day and then the thunderstorms hit, and some never return. The fish are non existent in the hot weather. Oct. and November are the best months, and the fish wake up. So we have 4 months of decent boating. No wonder my '08 Merc has only 40 hours.
I think that Snowbirds and tourists don't have much sense.
(Or else they would live here full time like us locals.)

Now South and Southwest Florida its a different story.
(Paradise) Never figured out why the tourists and snowbirds don`t keep driving until they reach Ft. Lauderdale/Miami or Ft. Myers/Naples.