Logo
FULL SITE MENU

BF15 Won't Fire

H

hippovet

New member
Okay, I probably did a stupid thing. I bought a boat with a 2008 BF15 without seeing the engine run. Good price, BUT. The seller assured me that the motor ran great, started every time, etc. Well, I got it home, checked the oil and tried to start it. NOTHING. It is an electric start and turns over fine. I first checked the spark at both plugs and that seemed okay. So it must be a lack of fuel. Both plugs were dry when I checked them.

I'm new to Honda Four Strokes and I'm not sure how to check to see if it is getting fuel to or from the carburetor. The bulb pumps up firm and when I removed what I thought was the drain plug for the carburetor, gas flowed out. The plug I removed had a pointed tip, kind of like a needle valve. The only carburetors that I'm really familiar with are on '52 to '67 3 hp Evinrude/Johnsons. They have the high speed needle located on the bottom of the carburetor float bowl, kind of where this thing was. However, this wasn't as smooth and sharp as I think a needle valve should be and there was no packing around it. Is this the drain plug for the carburetor on my engine or something else? I need a schematic of the carburetor and fuel system.

Any suggestions on where I should go from here? The motor has not fired for me at all.

Thanks
 
I don't know a thing about that engine, but they all have a safety kill switch that you need to make sure is in place. If questionable, disconnect it for your tests.
 
The screw near the very bottom of the carburetor's float chamber IS the drain screw. The only "metering" screw shouldn't be readily accessible as it is supposed to be covered by a chromed plastic limiter cover up toward the top of the carb on it's starboard side.

The drain screw was intended to just be backed off a few turns to allow fuel to drain from a nozzle cast in the float chamber and then flow out of the side cover via a small hose. The drain fitting on the side cover is located near the water tell tale fitting and nipple. It sounds like the hose on your motor may have been deleted.

Like chawk_man says, check the kill switch to ensure that it's not "tripped" and that the kill key on the lanyard is properly installed under the switch button.

You can test for a no fuel to the cylinders condition by injecting propane gas into the intake while cranking the engine. The plumber's torches that screw on to small propane canisters is a great tool for doing this. If the engine has spark, it will probably start and even respond to throttle control when introducing propane this way. Even if it doesn't start while doing this, it will try to run.

If your outboard has a black, rubber cylinder attached to the engine oil dipstick, remove it and shake all liquid from it. These are called "fuel chambers" but will, over time, collect water and can cause a hard/no start condition.

If you suspect no spark, you can use an automotive timing light to see if the ignition is being "triggered". If you get consistent flashes on the light but the engine still won't fire, you may want to try a new set of plugs. The ONLY plugs that I recommend using are the NGK CR5EH-9.
The Denso brand plugs just don't seem to work very well in these engines.

If you drain the fuel chamber and you have fuel in the carb, and you're positive that it's getting spark but not fuel to the cylinders, then you are probably going to need to take off, disassemble and clean a very dirty carburetor.
 
I removed and emptied the fuel chamber and reinstalled it. I squeezed the bulb in the fuel supply line until it was firm and then tried to start the engine. IT FIRED!!! However, it then immediately died. I then re-squeezed the bulb and started the engine several times. It immediately dies each time.

I wonder about the fuel pump. Could that be the problem? I don't think this engine has many hours and everything under the hood is very clean. Hopefully the carburetor is clean also, but maybe not.

Your thoughts?

Thanks
 
Ok, if it fires and you think the pump is weak, here's the test for that:

Keep squeezing the bulb and see if it starts and stays running. Because, when you do this YOU are the pump. Simple as that.

But, something else to consider here is that the engine is cold. It may be dying because it's not being properly enriched.

These have a device called a "bystarter" instead of the "butterfly" at the carb inlet that we all call the choke.

The bystarter is easy to test. It's held to the top of the carb by a clamp
that's held down by a single screw. Remove the screw and clamp and it lifts straight up out of the little "well" it sits in/on. Unplug it and lift it off the carb. Check that the oring seal is in good condition. Using jumper wires, apply 12 volts to the wire and ground to the housing. Watch the "pintle". It should start to extend after a few seconds. If it extends under power and retracts after power is removed, it is working.

The bystarter is in enrichment mode when not powered. When the engine starts, power goes to a heater coil inside the bystarter and causes the pintle to extend and shut off the enrichment passageway so that the engine doesn't flood.

The only way it can fail and keep a cold engine from running is if the pintle gets stuck in the extended position and doesn't retract when voltage is removed.

If you check the bystarter and it's ok and the engine won't stay running while you pump the bulb, you have a carburetor problem and a thorough cleaning and inspection is more than likely needed.

I say more than likely because, not knowing how much engine wear there is, it COULD be something else like jumped timing or low compression. BUT....the fact that it starts tells me it's more likely to be deposits in the carb.

These are FANTASTIC outboards but if not maintained correctly, including draining the carb religously, they will develop annoying problems. If you get it running properly and do your due diligence, you will have VERY LITTLE problems and get very long life out of a sound unit.

Ask all the questions you need to.

Good luck.
 
I squeezed the bulb while my wife turned the key. The motor started and kept running. When I stopped squeezing the bulb, it kept running. Now it seems to be running beautifully. All I can think of is that something was lodged somewhere and we knocked it loose, or some such thing.

Thank you for your intelligent assistance. I am now very happy and I don't regret my purchase. I woke up the past two nights thinking about the motor and had difficulty sleeping for awhile. Tonight I'll sleep like a baby.

Thanks again.
 
How does one routinely drain the carburetor? My old 3 hp Evinrude/Johnsons (I have four of them. Guess I'm a collector.) have a fuel shut-off valve that can be turned off while running the engine. Do I simply disconnect the fuel line from the engine while it is still running, letting it use up all the fuel in the carb?

Thanks
 
Ok, great!
If you use that new found knowledge and drain the carb when you won't be using the boat for a week or more, you will experience WAY less problems than the next guy.
And, yes, if you're putting the boat up for an extended period, pull the fuel hose and run it until it quits. THEN drain the carb as well.
Continue with only fresh, clean gasoline, sourced from a reliable retailer and your problems will be few with that outboard.
Glad you got it going and
Good luck.
 
Hi JGMO - great advice. Amazing engines. But ours has stopped working for some of the above reasons perhaps. We just replace the fuel pump hoping this would solve the dry plugs issue. It didn't. This is a manual start 2012 BF15 used all year at least once a week. The new pump pumps fuel when cranked as seen by the tube to carb from chamber. IE seems to flow through the chamber fine and push out plenty of fuel.
Could be that there a blocked jet or CDI unit. But plugs were out and sparked. Some other safety cut off. Overheating sensor, faulty kill switch.
Any thought would be very welcome before we take down the carb then buy a new CDI and are left with some cut off switches.
 
Hi lela2,

Well, if, as you say, the sparks are sparking, then I don't think that there's any problem with the kill switch or the CDI. Getting spark on one of these usually indicates all the "electrics".are ok. Even though there is the possibility of the spark being too weak, your description of "dry plugs" says lack of fuel to me.

I'm assuming you tried the pumping the bulb trick?

I always confirm a lack of fuel guess by using propane to artificially enrich the engine but I realize most aren't equipped or confident enough to do that.

I NEVER recommend using ether (starting fluid) unless in an emergency because of the damage it can cause to the engine.

My guess is that it's probably the carburetor. But....just a guess at this point.

You can try "spritzing" carburetor cleaner into the muffler while cranking (takes two people) to see if it will pop or cough. But you still need to be careful because you can use too much and, because it's a liquid, doing that can also cause harm.

A few questions:

This is a no start, right? As in: you pull it over and it won't cough or ever try to fire?

Did this problem start all at once or did it gradually get harder to start?

Have you checked your fuel tank vent or tried running with the cap off?

Are you positive that the fuel you're using is of good quality and is fresh?

Have you ever emptied the fuel chamber? That's the round, black thing mounted to the engine oil dipstick tube.

Does your choke knob stay pulled out all the way and not move back toward the closed position by itself when you release it?

Have the valves ever been adjusted?

This carburetor "fuel enrichment system" is NOT a conventional, butterfly valve type "choke". It acts more like a valve inside the carb. The cable for it can stretch and or buckle and cause the valve not to operate properly. That can cause hard/no start but usually only when cold.

Also, these carbs are VERY sensitive to ANY fuel contamination and can get plugged up easily as a result.

When that happens, a thorough cleaning will usually fix the problem. BUT...
...be forewarned...it's NOT a 20 minute job. The carbs are finicky with very small passages and can give you fits getting one clean.

Ask any and all questions but please, also answer mine.
 
Should have mentioned this earlier...
One quick trick you might try is to remove the carburetor drain tube, back out the drain screw a turn or two and then spray a liberal amount of WD-40 up into the float chamber.
This problem sounds like it could be a stuck float valve and, sometimes, WD-40 will get it moving. Lightly tapping on the float chamber with a screwdriver while someone pulls over the engine might help unstick it also.
But, even if this works, I still would recommend pulling the carb and inspecting the float and needle. If there's been water entering the carb it's best to clean it before it stops on you again.
 
Many thanks JGMO. 3 hours of TLC and it worked. Cleaned carb although there was no apparent varnish or dirt in the float chamber or the evap chamber or on the jets. But all jets cleaned with fine wire and carb cleaner. Took a bit of pulling to fire up but it did and ran smoothly thereafter. Conclusion is that the old fuel pump was probably okay and it was a pure fuel blockage issue. But new pump doesn't hurt on a 12 year old engine. Tiny jets and lots of them so any dirt would cause a stoppage. We were bracing for a new CDI unit and other stuff but your advice was correct. If there was a strong spark which there was, then that part working, thankfully. We avoided an easy $1000+ bill with some maintenance and help from yourself and this forum.
jgmo said:
Hi lela2,

Well, if, as you say, the sparks are sparking, then I don't think that there's any problem with the kill switch or the CDI. Getting spark on one of these usually indicates all the "electrics".are ok. Even though there is the possibility of the spark being too weak, your description of "dry plugs" says lack of fuel to me.

I'm assuming you tried the pumping the bulb trick?

I always confirm a lack of fuel guess by using propane to artificially enrich the engine but I realize most aren't equipped or confident enough to do that.

I NEVER recommend using ether (starting fluid) unless in an emergency because of the damage it can cause to the engine.

My guess is that it's probably the carburetor. But....just a guess at this point.

You can try "spritzing" carburetor cleaner into the muffler while cranking (takes two people) to see if it will pop or cough. But you still need to be careful because you can use too much and, because it's a liquid, doing that can also cause harm.

A few questions:

This is a no start, right? As in: you pull it over and it won't cough or ever try to fire?

Did this problem start all at once or did it gradually get harder to start?

Have you checked your fuel tank vent or tried running with the cap off?

Are you positive that the fuel you're using is of good quality and is fresh?

Have you ever emptied the fuel chamber? That's the round, black thing mounted to the engine oil dipstick tube.

Does your choke knob stay pulled out all the way and not move back toward the closed position by itself when you release it?

Have the valves ever been adjusted?

This carburetor "fuel enrichment system" is NOT a conventional, butterfly valve type "choke". It acts more like a valve inside the carb. The cable for it can stretch and or buckle and cause the valve not to operate properly. That can cause hard/no start but usually only when cold.

Also, these carbs are VERY sensitive to ANY fuel contamination and can get plugged up easily as a result.

When that happens, a thorough cleaning will usually fix the problem. BUT...
...be forewarned...it's NOT a 20 minute job. The carbs are finicky with very small passages and can give you fits getting one clean.

Ask any and all questions but please, also answer mine.
Click to expand...
This is a reply to previous to last post:

This is a no start, right? As in: you pull it over and it won't cough or ever try to fire?
CORRECT. NOT A POP. PLUGS DRY DESPITE FUEL FLOW TO PUMP AND CARB.

Did this problem start all at once or did it gradually get harder to start?
ONLY IN THE LAST FEW WEEKS. VERY RELUCTANT TO START, CONKED OUT LEAVING MARINA BUT I GOT IT GOING EASILY WITH CHOKE AND SOME REVS AND IT RAN STRONG FOR 45 MINUTES. WENT HOME. 2+WEEKS LATER NOTHING/NOW.

Have you checked your fuel tank vent or tried running with the cap off?
NO BUT WE FITTED A NEW FUEL PUMP AND FUEL IS GETTING THROUGH AND I HAVE A TRANSPARENT FILTER TO IT'S GOING IN

Are you positive that the fuel you're using is of good quality and is fresh?
JUST TOPPED IT OFF WITH NEW FUEL

Have you ever emptied the fuel chamber? That's the round, black thing mounted to the engine oil dipstick tube.
NO BUT WE TESTED THE FLOW FROM THE CHAMBER EXIT TO THE CARB AND IT GUSHED OUT WITH EACH POLL (MANUAL STARTER).

Does your choke knob stay pulled out all the way and not move back toward the closed position by itself when you release it?
STAYS OUT AND WAS WORKING

Have the valves ever been adjusted?
NO. WHEN IT RUNS IOT RUNS PERFECTLY. HOWEVER, EARLIER IN ITS LIFE AT TOP REVS IT DID CLATTER A BIT SO BACK IT OFF AND IT SETTLED DOWN. FOR A YEAR THAT HAS GONE.

COULD IT BE AN INTAKE VALVE ISSUE? BUT LAST USE HAD NO INDICATION OF ANY MAJOR FAIL LIKE THAT. IT RAN AFTER STALLING TICKED OVER UP TO THE SLIP THEN REFUSED TO START AFTER THAT AS MENTIONED.

We've cranked this with throttle full open and choke on to see if the plugs are wet but remain dry so it does point to the carb. Is there a main jet that gets blocked? I'm fearing a combo of gunk in any case.

This engine gets a ton of use and is usually wonderful but never serviced the carb. All other fluids etc changed as per. Plugs seem good. Had various Hondas and they are amazing including 47 year old original mini trail that pulls us 220lbs up the hill!.

Thank you again for your input and to the forum

Lela II
 
Ha ha, yeah!

But....it's a B.O.A.T.....

Break Out Another Thousand!


Or

Bring On Another Task!

Or

Being On Additional Therapy!

Or

Well, that's enough for now I guess.

Lela 2.....sailboat?
 
Ha ha indeed, We try to avoid BOAT on a craft that cost 5k and a Honda that cost 1500. Yes Sailboat. Catalina C250 1995. All thanks to your advice!
 
I might have spoken too soon. I went to the boat today 2 days after doing this job and it would not fire after many pulls. Plug was dry again. So I pulled some more, throttle wide open hoping to wet the plugs and with kill switch enabled. Then finally it fired.

Could this be a sticky intake valve with weak spring?

Also, and it may be a coincidence, when we originally tested for a spark we enabled (kill position) the kill and it still sparked. We always thought it cut the CDI out hence shutoff. Today I enabled it again after it finally ran and warmed up and restarted fine many times, but it kept running with the toggle out. I tapped the red button and it shut off. Applied WD40 and after some pushing the button in and out it seemed to cut off in the correct fashion with the toggle. Could this be part of the problem? And or valve? I am sure the carb and pump are fine and seemingly the CDI.
I will try it again tomorrow and if it starts as per then it was the switch all along. Otherwise, lost for ideas.
 
Back
Top