Honda Outboard Siesta Habit

[dlochner]

Our 2021 Honda 5hp outboard has developed an annoying habit, it likes to take afternoon siestas after each run.

After many trials and tribulations over the years, the little Honda finally started behaving, starting when asked on a single pull or maybe two. Our trust and faith in the little ICE was growing when it started its siesta habit, after shutting down after a long or short run, it won't restart for an hour or more.

Yesterday, we went to the dinghy dock, a 5 minute ride, shut the engine off, went in to take showers, and the engine refused to start, resulting in getting a tow back to the boat. A couple of hours later, the engine started right up on a single pull. Likewise after dinner, it started right up on a single pull.

I'm out of ideas on what is causing the need for a siesta and how to go about breaking the Honda's siesta habit. Any ideas?

 

[Davidasailor26]

Is it carbureted with an automatic choke by any chance? I have a lawn mower with a similar problem - once it’s warmed up I can stop it long enough to empty the bag, but if I stop long enough to talk to someone it’s *very* hard to restart. I’ve assumed it’s some minor blockage in the carb or just enough loss of compression from age that the auto-choke doesn’t give the right mixture anymore and the engine floods. I haven’t found a workaround yet unfortunately.

 

[dlochner]

Yes it has a carb with a manual choke. I may just have to take longer showers.

 

[SteveHughessails]

Have you checked the fuel tank vent and the fuel filter? Try unscrewing the fuel cap, see if it repeats or behaves. You should also be running sea foam in your fuel. Counters any ethanol and cleans.

 

[dlochner]

Have you checked the fuel tank vent and the fuel filter? Try unscrewing the fuel cap, see if it repeats or behaves. You should also be running sea foam in your fuel. Counters any ethanol and cleans.

We only run non-ethanol fuel, it is fresh fuel. Vents are fine. It is will start on one, maybe two pulls any time except when it has been run and then shut off. It won't restart unless it is allowed to sit for about an hour or more.

 

[JBP-PA]

It runs OK for a long time? Not an overheating problem?

When it wont start, have you checked the fuel & spark? Pull the plug, sniff it, check for spark.

 

[SteveHughessails]

We can’t get non ethanol fuel up here anymore. :-(

Hope you figure it out. I have an 8Hp Honda 4 stroke. It takes a few pulls to get her going but has been good.

 

[dlochner]

It runs OK for a long time? Not an overheating problem?

When it wont start, have you checked the fuel & spark? Pull the plug, sniff it, check for spark.

I don't believe it is a an overheating problem, I've been through that. When the engine gets too hot the electronic ignition shuts off. Since the engine is running fine and for fairly long periods of time 30 minutes or so, then it shouldn't be heat. I'm not completely ruling out over heating, just looking for alternative reasons.

Haven't pulled the plug, the plug wrench and the motor are usually separated when the engine won't start.

 

[JBP-PA]

Is it electronic CDI? My CDI went brain dead in a different way, it always killed the engine when I shifted into gear. Don't tell anyone, but I just bypassed the neutal switch.

 

[sailcapt340]

the engine refused to start, resulting in getting a tow back to the boat. A couple of hours later, the engine started right up

‍. I feel your pain. Now I have to say I am not laughing, but I so enjoyed reading this posting. I guess I am about to do what they call Highjacking a posting.
Dave, you brought me right back to 1972 just like a you had a time machine!
I had a brand new, Bright Lemon Yellow Chevy Vega that did the exact same thing…..Every Time I drove it more than an hour and shut it off. So regularly you could set your watch by it. We got towed back so many times we put a blanket and a picnic basket in the car just for 2 hour rest the motor needed. No matter where we went.
I just had to share that….you made us laugh today!
Okay, that said…..you’re on to the real issue here….

I don't believe it is a an overheating problem, I've been through that. When the engine gets too hot the electronic ignition shuts off. Since the engine is running fine and for fairly long periods of time 30 minutes or so,

It’s not the engine overheating, it‘s the (in my car case) aluminum starter and housing parts that had to cool off.
You may be able to get some sort of heat shield around the electronic ignition components and offset the problem. Or it could be as easy as opening the engine cover to let cooler air in.
I know I didn’t help you much but I really feel your on the right track with the ignition.
You gave us a blast from the past.

 

[dmax]

Next time it won't start, squirt some starter fluid in the carburetor - if it runs for a bit and stops then it's a fuel/air issue, if doesn't run at all, it's likely electric.

 

[pgandw]

I had similar starting issues with my 5hp Honda. Sometimes it was Siesta Time, and sometimes it wouldn't start for days. I have heard/read that the choke is the siesta time issue - here in North Carolina summers, the choke over-chokes the engine, and it won't start. But it also won't start without any choke.

I had the carburetor cleaned, and cleaned it myself. Both of which proved to be temporary fixes. I tried all the common "fixes" - only fresh non-ethanol gas, running it dry after each run.

To be honest, I gave up on the thing. I suspect my last non-starts were due to an issue with the EPA gas tank, that the air infill on a semi-permeable tank isn't good enough, that the tank fill needed to cracked open to allow the engine pump to suck gas. Or a check valve in the hose wasn't working correctly. But I sold the motor before I could test these theories.

I replaced the motor with an Epropulsion Spirit 1.0, and couldn't be happier. My friends will once again sail with me. On my 19ft Mariner, a full charged motor battery will get me a solid 12nm of range at 4kts. I use the electric motor far more than I did the Honda because it is so quiet and easy to start.

My Mariner has no battery or electrical system. So this summer I will put one in - planning on a 150AH LiFePO battery that will give a slow charge to the motor (one full charge replacement), and will be partially replenished with a 50-100 watt solar panel. This should give me enough for the max 4-5 day cruises I am planning.

Fred W
Stuart (ODay) Mariner #4133 Sweet P

 

[dlochner]

I suspect my last non-starts were due to an issue with the EPA gas tank, that the air infill on a semi-permeable tank isn't good enough, that the tank fill needed to cracked open to allow the engine pump to suck gas. Or a check valve in the hose wasn't working correctly. But I sold the motor before I could test these theories.

We did have a problem with the fuel line. The non-permeable fuel lines have a liner in the hose. That liner can detach from the hose and collapse blocking the fuel flow. This is for lines on an external tank. Took the Honda in to a Honda certified repair shop they called and said the motor ran fine. Brought the fuel tank and hose to them, in 2 minutes they found the bad hose, replaced it and it runs better than ever, except when it decides it is siesta time.

 

[Rich 35.5]

Try shutting off the fuel supply and let it run the gas out of the carb. When you come back in a half hour, see if it starts. That would eliminate vapor lock. If it still doesn't start, its probably a spark issue.

 

[shemandr]

I don't know much about engines. But an old and rough test for compression for an older car was to run it until it was warm. Then turn if off and try to re-start it. If it doesn't restart it has compression issues. Did you do a compression test?

 

[Sailor Sue]

Have you tried any combination of choke, no choke, partial choke, or twisting the throttle open and closed a couple of times before trying to re-start?

 

[dlochner]

Have you tried any combination of choke, no choke, partial choke, or twisting the throttle open and closed a couple of times before trying to re-start?

Yes.

Yesterday, I ran the motor several times with at least an hour or more between starts with no issue. It was also stopped and started again within 5 minutes, no issues. I think the motor must be a cousin of @Davidasailor26's lawn mower.

The most plausible theory involves heat. The motor is too new and lightly used to be a mechanical issue and since most of the time it now starts and runs well, mechanical and fuel issues would be ruled out or at least not be on the top of the list.

 

[degas]

Forgive me for starting with the obvious: Is the engine getting fuel, air, and spark? Make sure they're all ok.

The more likely cause is ethanol, which looooves to gum up little carburetors. My Honda 2.3HP was susceptible in the same way you describe. The longer then motor sits unused, the worse it gets.

My fix was learning how to clean the carb every season, using non-ethanol fuel (with isn't everywhere), and 1-2 cans of Seafoam every season.

 

[dLj]

Forgive me for starting with the obvious: Is the engine getting fuel, air, and spark? Make sure they're all ok.

The more likely cause is ethanol, which looooves to gum up little carburetors. My Honda 2.3HP was susceptible in the same way you describe. The longer then motor sits unused, the worse it gets.

My fix was learning how to clean the carb every season, using non-ethanol fuel (with isn't everywhere), and 1-2 cans of Seafoam every season.

He only uses non-ethanol gasoline - see post #5

dj

 

[dlochner]

Forgive me for starting with the obvious: Is the engine getting fuel, air, and spark? Make sure they're all ok.

The more likely cause is ethanol, which looooves to gum up little carburetors. My Honda 2.3HP was susceptible in the same way you describe. The longer then motor sits unused, the worse it gets.

My fix was learning how to clean the carb every season, using non-ethanol fuel (with isn't everywhere), and 1-2 cans of Seafoam every season.

The non-starting problem happens only under very specific circumstances. After running the motor for a 10 minutes (approximate time to the dinghy dock) and waiting 30 minutes, it won't start. This morning I ran to the dinghy dock, left the boat for 90 minutes, and it started. The motor seems to need a nap for at least 30 minutes and less than 90. That's the problem.

Trying to start with full choke, half choke and no choke does not seem to make any difference. Time seems to be the main factor in the start/no start problem.

I suppose the question is, do I just have to live with this? Or is there something that needs replacing to eliminating the problem?