BF8A dies at low throttle or idle

Hello,
1st time here, and this is my 1st Honda outboard, and 1st 4 stroke.
BF8A
BZBC 1400107
It has been running fine then last weekend it was hard to start, and when I did get it running, I had to play with the choke to keep it running, at lower throttle settings. I assumed that the idle/low speed jets are clogged.
I disassembled the carb and sprayed it down with cleaner. I sprayed through on e hole and could see cleaner coming out of the jets.
Put it back together, and when I tried to run it, nothing really changed. I still had to jockey the choke. I pulled the fuel line off the carb inlet, and used the bulb to force fuel through the pump and hoses into a bucket. Put it all back, and it seems to run ok now, but at idle it's still lean, as it will speed up when I pull the choke out about halfway.
1. glass inline filter looks real clean.
2. no leaks in hose or connections when I squeeze the bulb.
3. fuel spits out if I pull the line off the carb inlet and pull the starting rope.
4. just cheap 87 octane fuel with nothing added to it.

The filter always seems to have fuel in it but usually has air too. I read several other posts here and they refer to removing an idle screw for cleaning, but mine doesn't have one. Maybe I just didn't get it clean enough?
Is there a better way to test my fuel pump?
Thanks,
JIm

There is a brass plug on the side of the carburator towards the top. It is about the size of a pencil eraser. Behind it is the idle mixture screw and the passage that you will need to clean.

To remove it, drill a small hole into it (no more than a 1/4" deep. Then screw a screw into it and then grab the screw and pry out the brass plug. When you put the screw back in after cleaning, turn the screw in until it just closes all the way, then back it out 2 1/2 turns.

I would not worry about the fuel pump at this point. Squeezing your fuel bulb does the same thing as your fuel pump. If it did not improve with sqeezing, then it probably is not your fuel pump.

Mike

hondadude said:

There is a brass plug on the side of the carburator towards the top. It is about the size of a pencil eraser. Behind it is the idle mixture screw and the passage that you will need to clean.

To remove it, drill a small hole into it (no more than a 1/4" deep. Then screw a screw into it and then grab the screw and pry out the brass plug. When you put the screw back in after cleaning, turn the screw in until it just closes all the way, then back it out 2 1/2 turns.

I would not worry about the fuel pump at this point. Squeezing your fuel bulb does the same thing as your fuel pump. If it did not improve with sqeezing, then it probably is not your fuel pump.

Mike

Click to expand...

Wow,
Thanks for the advice.
I saw the cap (looks like a miniature freeze plug).
I was wondering why they made it without a low speed needle. They just made it newbie proof!
So is there a chance I can do it all with the carb on the motor? ie, pull the needle, spray carb cleaner in the hole, replace, adjust , test?
Jim

You might get lucky. Nothing ventured, nothing gained. Drain the carburator first, to allow air to flow back into the bowl. Used a little compressed air to blow it out. A small can of air that you use to clean off your computer works good.

I would not use anything more caustic than brake cleaner. I never use carb cleaner on Honda Carbs.

Mike

i almost forgot. There is also a slow speed jet located next to the idle mixture screw. That should also be removed and cleaned as well as the passage that it goes into. All this can be done with the carb on the engine. Although, it is hard to tell that they are clean unless the carb is off the engine.

The good news is...this carb is probably the easiest of all the Honda carbs to remove and clean.

Mike

hondadude said:

i almost forgot. There is also a slow speed jet located next to the idle mixture screw. That should also be removed and cleaned as well as the passage that it goes into. All this can be done with the carb on the engine. Although, it is hard to tell that they are clean unless the carb is off the engine.

The good news is...this carb is probably the easiest of all the Honda carbs to remove and clean.


Mike

Click to expand...

This is almost funny. I spend a lot of time on a sailboat forum. The guys there make it sound like it can't be done unless you are a trained professional!
They suggested buying a new carb, and send this one in for overhaul. I guess if money's no object... I've had quite few boat motors, mostly OMC stuff, and I have always been able to do my own work, but not seeing a low speed needle, I wasn't sure if I was on the right track. I guess I was !
thanks again.
Jim

I've just finally got the carb on my 8 horse working properly. That little carb wants to be easy to work on because it is one of the most finicky lil devils I've ever worked on. It took three cleanings before it finally kept working. The last time I did it, I put it through my ultrasonic cleaner and got a 'dirt explosion' off the bowl. And here's the best part; it was the fuel line causing the problem. Even though there is a fuel filter between the engine fuel pump and carb, it wasn't fine enough to keep out the dust that my fuel line was giving off. It takes very little to plug up those fine idle passages. I replaced the fuel line the last time I did the carb and all is well

The fuel line might have been coming apart inside and collapsing to limit the flow of the fuel.

Good lesson for all of us.

Thanks for the feedback.

Mike

Haven't been here in a while.
Up date on my issue.
I have had several more episodes where I get to the boat ramp and start my motor. It starts in 2 or 3 pulls, runs a few seconds, dies, and then I go through hell before I get it to run reliably. Not every time though. When I take the carb off for inspection, I never find anything in it.
Usually it's acting like it isn't getting fuel. Last time it flooded the bowl and the top of the carb was wet. I had to pull the fuel line off the motor, get it running, then reconnect it. After that it was good all weekend.
I have never had this much trouble with an outboard motor before. Maybe I need to trade it in on a good old '60's era Evinrude!
Dual points, and no cam. LOL.
When setting the low speed needle, I get the motor warmed up, idle it down and then run the needle in and out until I find the sweet spot. I usually leave it about a quarter turn rich from that point cause it seems to help with the 1st start of the day.
This last time I ran the motor for a few miles at about 1/2 throttle, maybe a little less. I'm doing about 4 mph.
The motor kept sounding like it wanted to run on one cylinder. I could speed up a little and it would smooth out.
Before I go out again I'll run it at home and maybe put new plugs in, but the ones that are in it now don't have much time on them. So they should be good.

There are some very fine holes / jets in these carburetors.--------------My bet is that you missed the most important one in the plug that screws into the top of the carburetor.

HMMMMM??
I took the carb apart. drilled out the plug and removed the low speed needle. From there you can spray carb cleaner through and you can see it flowing out of the little jets.
Is there a second plug on the top that I might have missed?

Just an example -------------on a 98----- 8 HP carburetor it is part # 10 that is often overlooked ------It has a tiny hole in it -------I keep a piece of electrical wire in my wallet and occasionally help folks to poke a single strand of wire in it. Runs like a top after that.

Planning a trip starting Saturday. I tried running the motor last night and I can't get it to idle to save my life!
I guess I have to take it apart and clean it again. This time I think I'll replace the fuel line and bulb too.
This is definitely the most finicky motor I've ever had.
I didn't run the gas out, and it's been setting for a few weeks.

Not sure what item #10 is, but I took the carb apart and cleaned it again.
I took the thing that screws in on the top of the carb and worked a piece of wire in through the tiny little hole in the end.
reassembled it and put it back on the boat. I also installed a decent fuel filter. Dumped the old fuel and refilled with fresh gas and stabilizer.
Engine runs like a top now! Used the boat over the weekend, then went back on Monday evening and flushed with fresh water. Still runs good.
This time, I remembered to pull the fuel line off and ran the gas out.

When you follow instructions you -------------" walk on a path forward and make progress "-----------------------Good job.

After reading this I had to register so that I could thank hondadude. You've just saved me from over four years of grief with this outboard. Bought this outboard new in 2015 and it idled fine for about six months. I've researched this issue when mine decided to quit idling, too. All I found then was people posting that the idle mixture was set at the factory and you could not change it. Sounded ridiculous because all engines that I have ever worked on had an idle mixture adjustment. This time I was so fed up that I persisted until I found this thread. I did as you instructed and the outboard now idles like a champ! The brass plug on mine is where you stated, but it is on a slant, so that almost threw me.

Much thanks!!