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Honda bf5 troubles abound

A

arian

New member
Hey, so a month ago i purchased a refurbished outboard from my local chainsaw shop who happens to also deal in and maintain various small outboard motors, ATVs, you name it. Its a small rural town so most buisnesses tend to be multitaskers.

This 5hp honda came with a guarantee that if it doesnt run as it should they would work on it until it does.

A month later they are baffled. You might say its their problem to fix it or reimburse me and they are not argueing anything to the contrary. But I do feel bad for them in such a small town and iam hoping to help point them in the right direction a bit if it might be something specific to these engines.

So to give a full picture.

The motor is used, from 2006 and stood idle in the back of their shop for years abandoned by its previous owner who didnt pay for his repairs.

Before selling it to me they did the following:

Ultrasonic cleaning of carb
testing cooling in a watertank
changing filters
new oil
testing if it runs on the first pull.
idled it and revved it.

they reportee it all worked perfectly in the tank.

Once i took it to my boat it started fine. however the throttle wouldnt go above start position wile in forward gear, after 30 minutes of running it just died and wouldnt start again.

Back in the shop they tested it and it started but blew Steam and hot water.

They changed out the thermostat, waterpump, pretty mutch every moving part in the system, adjusted some stuff i fail to remember on the throttle, new headgasket as well because it clearly overheated and they thought it could have damaged it (i am not mutch of a mechanic myself)

So i went out again today, started first pull, no problems until i tried to go full throttle, rpm would start dropping off as soon as i went past 3/4 throttle. Then after an unknown distance going that speed the engine just quit running again.

It would imediately start up again on first pull, but increasing throttle to a certain point imediately kills it.

starts up again, i try going home on the start position throttle, boat barely moved forward and motor dies again. Now i have to give more throttle to start again and lower imediately to keep it going a while.



This becomes a repeated cycle the whole way home, dies, starts and limps, dies again.

no sputtering, it just cuts the engine abruptly.

going over a shallow area i raise the engine up a bit and go at slowest speed to clear the area. Ofcourse at this point it cuts out no matter what speed i go. As i lower the motor again it sizzles and steam shoots out of the water hole for a second (motor is off at this point)

Basically it just keeps going like this for 2 hours until i limp it home.

Now iam no mechanic but i have been around engines before. Does this perhaps sound like its not getting fuel? Yes obviously i opened the vent on the tank.

fuel line is about 180cm long. the tank is under my seat directly in front of the motor.

So to summarise whats happening: cant go high throttle without rpm dropping at first, then just dies constantly but it does restart everytime.
 
Hi,

I've never worked on this model and don't have the manual.
From here I can only offer some ideas and a bit of speculation but I'll give it a go.

First off, your comments about overheating and, especially, "sizzling and steaming" worry me. While I don't readily think that is the root cause of your consistant power loss and shut down, it could still be a factor. Here's why:

If, when lifting/trimming the outboard to go through shallows, you might be inadvertently starving the pump for water by getting the intake screens too high. If that happens, for only a few seconds, it can kill the impeller and ruin the pump resulting in overheating. The pump needs water to cool and lubricate the impeller and the cover it wipes against. You need to be very careful not to deprive the pump of water.

I'm not certain but I think that this outboard has engine protection built into the CDI. If so, and it overheats, it will go into "safe" mode and de-power the engine. That "limp home" program won't typically shut the engine off though so I don't think that's the cause of your issue.

This sounds more like fuel starvation.

The carburetor on this model is very simple and I think the ultrasonic should usually do the trick for cleaning. But, I always like to hit them with carb spray to make certain everything is clean and clear.
There's an external, removable jet on these that you can remove and spray and then use the little straw that comes with the can to hose out the passage inside the carb. See item 28 in the link below. You don't need to remove the carb to do that and sometimes it helps.



Have you ever tried squeezing the primer bulb when it's losing power?
If not, you should try that to see what happens.

Let's look at your fuel supply and tank.


The easiest way to eliminate a tank and/or hose issue is to use a different setup. If the shop has one they'll loan you to try, do that. If not, check yours out thoroughly.
If the hose is old and shows signs of wear or cracks, replace it along with the primer bulb. If that's not in the budget, try to determine that it's sound and not sucking in air by plugging one end with your finger and try to forcefully blow cigar smoke through it while gently flexing it.

It depends on which type tank you have so this is generic advice:
Look at item 5 (or 25 in the other style tank) in the link. You can remove the entire pickup tube and clean that screen. Make sure that the tube isn't cracked or split and that there's no "crud" or debris in the tank.

You .mentioned that you made sure the vent valve is open. Even so, it could still be partially clogged. A quick shot of that carb spray will ensure that it's clear.

The arrow on the primer bulb obviously indicates direction of flow but I've seen them installed backwards.

Also, the check valve inside the bulb works best when the arrow is pointing up....at least slightly. The check valve can hang open if the bulb is laid flat in the bottom of the boat.

Take a good, hard look at the fuel line quick disconnect(s). They wear out and won't fully open if the pin that pushes the valve gets too short.

Also, it's important that the latch is tight and secure. If not, the valve won't be held fully open.

I have other ideas about what might be happening but these things are at the top of my list so I'll stop for now.
 
wow thanks! thats alot to go over.

It does shoot water trough the hole when "trimmed" but it seems it still heats up enough that when the engine cuts out alot of heat transfer takes place from somewhere.

I hope its the fuel line/tank il try that first
 
So is it always pumping water out the telltale strongly? Even when steaming? Does the water coming out get really hot to touch?

Did they install a full water pump kit or just a new impeller? They should install the full kit.

I’m not familiar with these small Hondas but my 1999 FI 130 will go into limp mode when it gets overheated, then it will shut down, so maybe your issues are overheating.

If the outboard sat around for a long time, it could easily be fuel related. The advice you got already is excellent, Jgmo is the pro on these small carb outboards. Getting those tiny carb passages cleaned out after they get clogged due to a lack of use is very difficult on Hondas.
 
NSDON said:
So is it always pumping water out the telltale strongly? Even when steaming? Does the water coming out get really hot to touch?

Did they install a full water pump kit or just a new impeller? They should install the full kit.

I’m not familiar with these small Hondas but my 1999 FI 130 will go into limp mode when it gets overheated, then it will shut down, so maybe your issues are overheating.

If the outboard sat around for a long time, it could easily be fuel related. The advice you got already is excellent, Jgmo is the pro on these small carb outboards. Getting those tiny carb passages cleaned out after they get clogged due to a lack of use is very difficult on Hondas.
Click to expand...

They did change the whole system. as far as i know they also cleaned the whole carb system etc and they had it running in the shop. Overheating is still a real possibility, it does get quite hot to the touch, more so than iam used to from for instance mercury. I will check the water again, it was cool when i checked it but i neglected to check again later.


The shop gave me a new fuel line to try for now. Otherwise they will take it back for more maintenance.

I will go out tonight and try as mutch of your suggestions as possible then report back to the shop
 
It should get warm but not hot to the touch, I’ve run mine in a barrel, it’s a 2.3 L 4 cylinder, it’s taken a long time at 1500rpm for it to get the barrel up to 160F- that’s a warm bath, but not hot.
 
the shop borrowed me a brand new set, original honda. It improved the throttle but didnt fix it shutting down. Its strange because after 24 hours it runs as normal again, then after 2 hours or so it shuts down, water coming out is cool. Aftee it shuts down even anchoring for 2 hours wont make it restart.

I can however keep it idling in neutral by lightly pumping the primer. The moment i put any load on it it dies again.

for now the shop gave me a mercury 4hp to use. Their mechanic is on vacation, they suggested i swap them permanently if i like the Mercury however i would need to toss another 200 for the mutch newer motor splitting the difference with them. They are willing to keep fixing the honda but would rather we cut our losses as it has already cost them twice the price they sold it for in repairs. They would rather just call it a loss and sell it as a fixer to at least recover some expense from it.

I have a bad bias towards mercury based on experiences from years ago, one after the other would crap out over the years. The old 2 stroke penta has been running for 50 years at least, that one is oficially dead tho, entire housing behind the prop exploded.

I have a very good bias towards honda based on their old CRV cars, been offroading in one since 2004, has 600.000km on it.

But perhaps their marine stuff isnt as reliable, or its just this particular motor.
 
Sounds like a lack of fuel, carb may need more cleaning?

On the cooling side, remove thermostat and run it without it, see if anything changes?
 
Hondas seem to be really fussy on the cooling system, very easy to get a blockage enough to shut it down.

Same goes for the carbs in the small hp outboards, very hard to get them cleaned out with those tiny passages and jets. And old gas will clog them up.
 
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