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BF8 Carb Question

E

ezlivin

New member
"So my BF8 isnt idling right,

"So my BF8 isnt idling right, I pulled apart the carb (looked sparkly clean) and ran a boat load of cleaner through every hole I could find. Took out the main jet cleaned it, still wont idle.

Here is a link to a blowup of the carb, http://www.boats.net/parts/search/Honda/Outboard%20Engine/0/BF8AH%20SA%20OUTBOAR D%20ENGINE,%20JPN,%20VIN%23%20BACS-1000001/CARBURETOR/parts.html#

Is there a seperate idle jet somewhere that I'm missing, sorry I'm pretty green at this but learn quick, hopefully a little guidance can point me in the right direction."
 
"Remove items 6 & 10, ther

"Remove items 6 & 10, there are passagways (idle jet system) that go from there into throat of carb to clean.

Also notice that the entire New Carburetor (item 11) is less than $100, which is why it does not pay to have your Honda Technician cleaning it for you."
 
"Pilotart you were on the righ

"Pilotart you were on the right path, I removed item 10 but never removed the pilot screw (6) when I pulled the carb apart.

I just opened the pilot screw wide up and closed it with engine running until the idle was stable, I could actually hear when it started running better as it was real choppy at first and then it seemed to clear itself out, its about 3 turns from closed and idled for 10mins without an issue.

I have to ask what does item 10 do, it is completely closed and was that way all last year (last spring I had a local shop clean it, decided this year to save $200 and do it myself).

Thanks!!!!!"
 
Item #10 is a screw that plugs

Item #10 is a screw that plugs a hole used in manufacturing to install the idle circuit jet. The jet is VERY VERY tiny and not removable (at least not on mine) The idle circuit passageway has more turns in it than a maze. #10 is at a point in the idle circuit where it makes a right angle turn. #10 plugs the "T" junction so that the passage is a just right angle.
 
"Here goes nothing...I have an

"Here goes nothing...I have an 8 horse 4 stroke honda outboard, 9' wood floor inflatable keel dinghy. I weight 290 and my wife weighs 180. Should I even HOPE to get this set up on plane? I can do it with just me since I mounted one of those wings to the motor but it will not do it with both of us. Has the mass of my ass finaly limited my potential"
 
"Joe - unfortunately, it looks

"Joe - unfortunately, it looks like your analysis is correct. You are trying to push about 370 + 350 = 720 lbs of boat with a relatively high resistance hull across the water with 8 hp. I'm sure there are some marine engineers on this site that can give you the math. But my personal experience says it's not likely to work. What's the max horsepower rating on that dinghy?"
 
max for the dinghy is 5 horse.

max for the dinghy is 5 horse. West Marine...got it used for a good deal so I am not disenchanted. Just tired of watching everyone else in their hard bottom ribs zoom circles around us laughing and mumbling something about those "inflatable Keel" people. I do have to say that when I do get it up on plane with just me in it the floor does a lot of dancing and does not feel exactly stable....probably a good thing. Hard bottom land here we come.
 
"Hard start Honda BF8.
I have

"Hard start Honda BF8.
I have a very low hour Honda classic 8 that is just a bugger to start cold. Once started it runs fantastic. The motor had sat for 5 or so years when I purchased from original owner. I pulled the carb and boiled it out prior to putting in service. No real help, after a few more frustrating trips out I broke down and bought a new carb. I thought it helped but now it takes possiblt 20 pulls and not the 50 that it use to take (I am a heart patient and this is getting old). As another issue, or possibly related, the Honda , while warm will run all day long with no other issues. If I turn off and sit for any period of time the Honda will start right up with just a small tug on the rope. When I check the plugs they appear heavy sooted and black.

If I put new plugs in the Honda will start up OK...I don't feel that it is right that I have to replace the plugs on each trip??

Any thoughts?

BTW, I have replaced the fuel pump diaphragm also.."
 
Have you "ever" had it

Have you "ever" had it start with ease? If not- you may be starting it wrong. This motor must be throttled up a little to start. Do not use the choke unless it is real cold. Your engine is getting to much fuel if the plugs are not clean and almost never need replacement. If you would have just one spark plug fouling I would suspect the cam belt. This sounds like the idle circuit. either the adjustment or a flooding condition. You are looking for just the smallest amount of extra fuel to cause this. Is the exhaust visible?
 
"Thanks for the reply. It will

"Thanks for the reply. It will start relatively easy- 4 to 8 pulls with a new set of NGK plugs. But if I try a second trip on the same plugs then the Honda starts very hard, I normally set the throttle to start and pull the choke. I will be going out again this weekend and will try with no choke ( temps around here are near 80') and I will give it a bit more throttle.
As for the idle circuit, where would I look for it??
Both plugs foul equally. Since I only troll with the motor would you recommend that I run it up to 50% + power for a period of time before shutting down??

Should I be burning the gas off the carb each trip?

After the initial start, the 8 runs like a Swiss watch.

Thanks for the advice..

Randy"
 
"I used to cross hand start th

"I used to cross hand start the 7.5's in my charge. Thats left hand across and on the throttle and right hand on the rope. This method would hold the throttle open against the neutral stop. Try re-adjusting your idle mixture again.

I used to run in on the last gas by disconnecting the fuel line.

Having it push hard before shut down might help with the restart.

You might inspect your crankcase vent hoses and the plastic piece that holds the dip stick. If you have a vapor or oil leak, it will be a mess and might be getting to the engine. What is your oil consumption?"
 
"Oil consumption is zero. Wou

"Oil consumption is zero. Would it help to go synthetic?

I replaced the fuel pump diapragm 2 years ago and stopped 'making' oil. I felt that gas was getting into the crankcase via the little rubber diapragm. Since I replaced it my oil level is where it is supposed to be.

I have hardly any exhaust ...On start up possibly a little, but normally I am 'dancin' a little jig just happy it started, that I don't take time to notice.

On mid to full throttle it runs very smooth and seems to want to get out and go!

I will give your suggestions a try this weekend. I got my wife out in my boat finally ,after 30+ years of marriage and 4 boats! Now she is becoming my fishin buddy...life can't get better than that!

Randy"
 
"Synthetic was what ran in the

"Synthetic was what ran in the fleet at Lake Syskiyou. They smoked a little bit more but on tear down, we never bought a piston or crank. With a million hours on one and smoking like a chimney I only replaced the top rod and had to shim back the front gear case to get a rebuild that ran like new.

My girl friend in a boat was like holding a feral cat over a bath tub. So I'm happy for you!!"
 
"William
Will go out and get

"William
Will go out and get some Mobil 1...

Also, love the feral cat anology....gave me a laugh!

Thanks for all the advice...will let you know how it turns out..

Randy"
 
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