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Author Topic:   Running an F60 or F70 out of gas

tedious posted 08-17-2010 05:32 AM ET (US)
I have a Supersport 15, and run 2 separate 6 gallon tanks in the stern. The fuel protocol with my old Johnson 70 2-stroke was: make sure the tank that's not connected is full before leaving the dock, run until the motor starts surging, and then switch over to the full tank, pump the bulb, and go.
I am getting a new F70 - can anyone tell me whether that same method is going to work? What happens when you run out of fuel? Does the motor start surging, just cut out suddenly, or what? Hopefully it doesn't go into "limp home" mode or something unrecoverable.
I'd imagine an F60 works the same, so any real-world experience from someone who has one would be much appreciated. Thanks.
Tim
Peter posted 08-17-2010 07:21 AM ET (US)
Why wouldn't that method work? There is no limp home mode for a running out of fuel condition for any outboard motor.
Given that all internal combustion engines I've had, 2-stroke or 4-stroke, carb'd or DFI, outboard or lawnmower engine, exhibit the same change in running characteristics when they are running out of fuel, I'll bet that you will be able to notice a different running characteristic (call it "surging" if you want) as the F70 motor is running out of fuel which will be your sign to switch tanks under your protocol.

tedious posted 08-17-2010 07:35 AM ET (US)
Thanks Peter - your expectations match mine, but I'm hoping to hear from someone who actually has experience with the F60 or F70, or I guess any other recent fuel-injected Yamaha 4-stroke for that matter. I don't want to be surprised or have any difficulties the first time I run a tank dry.

Tim
SIM posted 08-17-2010 08:06 AM ET (US)
Never ever run a fuel injected engine out of fuel on purpose. The electric fuel pumps need fuel rolling thru them. Running them dry prematurely wears them out. The debris from the pump gets sent thru the fuel system downstream to the injector screens.
Proper winterization(per Yamaha) is to run stabilized thru the fuel system and as a final procedure after all winterizing is done, drain the VST of fuel. All new Yamaha's have provisions for doing this.
If the engine is going to sit unused for more then one off-season, there are other things I would recommend doing.......like draining the complete fuel system.
Most EFI 4-strokes will buck and shake for a few seconds, then shut off when run out of fuel.

Tohsgib posted 08-17-2010 11:36 AM ET (US)
I agree with SIM...worst thing you can do to an EFI engine is run it out of fuel. The injectors can go south. You are also sucking all the crap out of the tank. In the past I did as you did but now I make sure I don't run out. EFI is a closed system so air does not enter it to turn gas like a carbed setup. No need to really drain it unless you know it is a long time. Mine has gone 7 months and starts just like it was running yesterday.
tedious posted 08-17-2010 02:12 PM ET (US)
Thanks for the info folks - I will certainly plan to avoid running the tank dry.
Tim
Peter posted 08-17-2010 03:28 PM ET (US)
With the apparent delicacy of the EFI system, it might be prudent to install a fuel filter/water separator even if the tanks from which fuel is drawn are portable.
tedious posted 08-17-2010 09:02 PM ET (US)
Not sure about delicate, Peter. In general, I'm very pleased with the performance of modern electronic fuel injection systems, in both boats and cars, compared to either older FI systems or carbs. Yes, I do know you're a big fan of older 2-strokes. I am too, and the Johnson 70 I sold was a great motor. But I also like boating with my wife, who didn't like the noise and the smell of the old warhorse, nor the rough idle.
In any event, I already had a 10 micron Racor water separating filter in place. Probably not critical to have a filter with the portable tanks, but I am very conservative that way. The ocean is always trying to inconvenience you greatly, or even kill you, so I look at additional safety margin as just evening up the odds a bit.
Tim
Peter posted 08-17-2010 09:49 PM ET (US)
The advice given by SIM certainly suggests that the EFI system is more delicate than the carb'd system you had on your old 2-stroke. Unlike the EFI system, there were no worries about running the carb'd 2-stroke out of gas.
In any case, you've already got the fuel filter.
Newtauk1 posted 08-18-2010 05:16 AM ET (US)
Ask the manufacturer. They know best.I bet your warranty does not cover you if there is a problem and you state "well the nice fellers on the internet said to do this..."
tedious posted 08-18-2010 08:06 AM ET (US)
Thanks guys - SIM's advice (avoid running out of fuel routinely, but if it happens by accident, not the end of the world) makes sense to me, so that's what I'll do.
Don't be calling my new motor delicate or I'll hit you with my purse;-)!
Tim
Peter posted 08-18-2010 11:09 AM ET (US)
Ok, ok, last thing I want is to be hit by your purse so rather than delicate, it's "less robust". ;)
Tohsgib posted 08-18-2010 11:54 AM ET (US)
If EFI was less robust I doubt they would put it on outboards, Jet Skis, and motocross bikes which see the worst of the worst conditions.
69boo307 posted 08-19-2010 08:05 AM ET (US)
I have a 15 with 2 6 gallon tanks as well.
My 'limp home' mode is to switch fuel tanks when I get down to about 1/4 tank. Then I know if I run the other tank dry I have at least some reserve that would likely get me to shore or some dock or ramp, if not back to the boat ramp I started from. I never run my first tank dry before switching.
69boo307 posted 08-19-2010 08:07 AM ET (US)
BTW, the problem with running an EFI engine out of fuel is that most electric fuel pumps are cooled by the fuel passing through them. The danger is not damaging the EFI system itself but burning up your fuel pump.
If you have a mechanical fuel pump, no worries.

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Author	Topic: Running an F60 or F70 out of gas
tedious	posted 08-17-2010 05:32 AM ET (US) I have a Supersport 15, and run 2 separate 6 gallon tanks in the stern. The fuel protocol with my old Johnson 70 2-stroke was: make sure the tank that's not connected is full before leaving the dock, run until the motor starts surging, and then switch over to the full tank, pump the bulb, and go. I am getting a new F70 - can anyone tell me whether that same method is going to work? What happens when you run out of fuel? Does the motor start surging, just cut out suddenly, or what? Hopefully it doesn't go into "limp home" mode or something unrecoverable. I'd imagine an F60 works the same, so any real-world experience from someone who has one would be much appreciated. Thanks. Tim
Peter	posted 08-17-2010 07:21 AM ET (US) Why wouldn't that method work? There is no limp home mode for a running out of fuel condition for any outboard motor. Given that all internal combustion engines I've had, 2-stroke or 4-stroke, carb'd or DFI, outboard or lawnmower engine, exhibit the same change in running characteristics when they are running out of fuel, I'll bet that you will be able to notice a different running characteristic (call it "surging" if you want) as the F70 motor is running out of fuel which will be your sign to switch tanks under your protocol.
tedious	posted 08-17-2010 07:35 AM ET (US) Thanks Peter - your expectations match mine, but I'm hoping to hear from someone who actually has experience with the F60 or F70, or I guess any other recent fuel-injected Yamaha 4-stroke for that matter. I don't want to be surprised or have any difficulties the first time I run a tank dry. Tim
SIM	posted 08-17-2010 08:06 AM ET (US) Never ever run a fuel injected engine out of fuel on purpose. The electric fuel pumps need fuel rolling thru them. Running them dry prematurely wears them out. The debris from the pump gets sent thru the fuel system downstream to the injector screens. Proper winterization(per Yamaha) is to run stabilized thru the fuel system and as a final procedure after all winterizing is done, drain the VST of fuel. All new Yamaha's have provisions for doing this. If the engine is going to sit unused for more then one off-season, there are other things I would recommend doing.......like draining the complete fuel system. Most EFI 4-strokes will buck and shake for a few seconds, then shut off when run out of fuel.
Tohsgib	posted 08-17-2010 11:36 AM ET (US) I agree with SIM...worst thing you can do to an EFI engine is run it out of fuel. The injectors can go south. You are also sucking all the crap out of the tank. In the past I did as you did but now I make sure I don't run out. EFI is a closed system so air does not enter it to turn gas like a carbed setup. No need to really drain it unless you know it is a long time. Mine has gone 7 months and starts just like it was running yesterday.
tedious	posted 08-17-2010 02:12 PM ET (US) Thanks for the info folks - I will certainly plan to avoid running the tank dry. Tim
Peter	posted 08-17-2010 03:28 PM ET (US) With the apparent delicacy of the EFI system, it might be prudent to install a fuel filter/water separator even if the tanks from which fuel is drawn are portable.
tedious	posted 08-17-2010 09:02 PM ET (US) Not sure about delicate, Peter. In general, I'm very pleased with the performance of modern electronic fuel injection systems, in both boats and cars, compared to either older FI systems or carbs. Yes, I do know you're a big fan of older 2-strokes. I am too, and the Johnson 70 I sold was a great motor. But I also like boating with my wife, who didn't like the noise and the smell of the old warhorse, nor the rough idle. In any event, I already had a 10 micron Racor water separating filter in place. Probably not critical to have a filter with the portable tanks, but I am very conservative that way. The ocean is always trying to inconvenience you greatly, or even kill you, so I look at additional safety margin as just evening up the odds a bit. Tim
Peter	posted 08-17-2010 09:49 PM ET (US) The advice given by SIM certainly suggests that the EFI system is more delicate than the carb'd system you had on your old 2-stroke. Unlike the EFI system, there were no worries about running the carb'd 2-stroke out of gas. In any case, you've already got the fuel filter.
Newtauk1	posted 08-18-2010 05:16 AM ET (US) Ask the manufacturer. They know best.I bet your warranty does not cover you if there is a problem and you state "well the nice fellers on the internet said to do this..."
tedious	posted 08-18-2010 08:06 AM ET (US) Thanks guys - SIM's advice (avoid running out of fuel routinely, but if it happens by accident, not the end of the world) makes sense to me, so that's what I'll do. Don't be calling my new motor delicate or I'll hit you with my purse;-)! Tim
Peter	posted 08-18-2010 11:09 AM ET (US) Ok, ok, last thing I want is to be hit by your purse so rather than delicate, it's "less robust". ;)
Tohsgib	posted 08-18-2010 11:54 AM ET (US) If EFI was less robust I doubt they would put it on outboards, Jet Skis, and motocross bikes which see the worst of the worst conditions.
69boo307	posted 08-19-2010 08:05 AM ET (US) I have a 15 with 2 6 gallon tanks as well. My 'limp home' mode is to switch fuel tanks when I get down to about 1/4 tank. Then I know if I run the other tank dry I have at least some reserve that would likely get me to shore or some dock or ramp, if not back to the boat ramp I started from. I never run my first tank dry before switching.
69boo307	posted 08-19-2010 08:07 AM ET (US) BTW, the problem with running an EFI engine out of fuel is that most electric fuel pumps are cooled by the fuel passing through them. The danger is not damaging the EFI system itself but burning up your fuel pump. If you have a mechanical fuel pump, no worries.