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bf8ah carb question

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mickhodapp

Member
hello folks, i am having trouble unscrewing the main nozzle on my bf8ah carb ( part#12in the boats.net diagram) to the point that the brass slot is becoming deformed & am wondering if i'm turning it the wrong way because it won't budge turning it counter clock wise.if it is not reverse threaded is it supposed to be that tight?
i have cleaned the carb real good except for the main nozzle but am not getting gas from the carb to the plugs & feel that the holes in the nozzle might be plugged. this part is obsolete so i am afraid to put any more pressure on it trying to get it out. if i ruin it then my only option would be a new carb. there is good gas in the bowl,float needle is clean & spring works & float moves up & down but i don't know if it is adjusted right. i have a shop manual with the settings but don't have a float gauge. if i take out the # 10 screw plug & shoot compressed air through it it starts up on the 2nd pull & runs fine, throttles up good & idles down fine. if i shut it off & let it sit for a couple of hours it won't start again until i take the screw plug out & do it again. any thoughts would be appreciated !
 
It will be a normal thread. Turn counter clockwise to loosen.
Make sure the carb is mounted firmly in something or on the motor and use a PROPER, good quality screwdriver whose bit fills the slot perfectly.
If you have a good screwdriver a slight rap with a hammer as you turn might help.

Someone with more knowledge than I might say if an impact driver would be ok to use.
 
thanks for the info. the slot is partially gone & has is widened out from someone else's attempts. now that i know for sure that it is a normal thread i will block it very carefully in a bench vise & fee if i can get a good bite on it on the outside of it with some sort of a vice grip. i'll post my progress. i've got pretty good hand strength but King Kong must have been the last monkey to work on this carb because i can't budge it,even after soaking it with penetrating oil !
 
You can give it a couple of good whacks with a 1/4" pin punch and hammer to "unbind" the threads. That should make it a bit easier to turn no matter how you go about getting a grip on it.

These should always be initially engaged and removed with a good quality impact driver to keep the slot deformation to a minumum. But, because of "previous attempts" at removal I've had to cut a "new" slot, perpendicular to the original, with a Dremel wheel to get them out.

As long as the jet hole isn't enlarged or damaged in any way, the jet can be reused. But a new one isn't very expensive if you choose to replace it.
 
I decided to put the carb back on the motor yesterday in spite of the fact that i could not loosen the main nozzle to clean it because i did get a piece of debris to come out of it when i shot compressed air into it & it started right up on the 2nd pull & runs fine now so i'm going to leave it alone. the idea of a new carb is a good idea but i live in puerto vallarta,mx where honda motors & parts are rare & getting parts ordered from the states is very expensive ( duty tax ) & a gamble. i am still waiting for parts ordered from boats.net on the 27th of Febr. thanks to everyone that replied with their valuable information & being a boat owner i'm sure i'll be back on this forum in the near future ,lol!
 
re slotting it is a great idea !! never thought about that but like i posted today,it started right up yesterday after i blew out a small piece of dirt. it runs fine now so i think i'll "leave the sleeping dog alone". thank you for your reply. can you tell me how to replace the oil pressure light & also, for future reference, what is the correct fuel air mixture setting ? i know the idle setting. the carb is for the bf8ah motor
 
no, i didn't because i was afraid of maybe ruining a rubber seal or o-ring if i overheated it since i have not done this before but is probably a good idea,thanks !
 
I agree with you...if it ain't broke....don't cause yourself any headaches.

Changing out the oil indicator lamp is very straightforward. As you can see by referring to the link below, item #16, the lamp is a complete assembly. You simply unplug the two wire connectors and then remove the retainer nut that holds the lamp to the case.

http://www.boats.net/parts/search/Honda/Outboard Engine/0/BF8AH SA/FLYWHEEL/parts.html

I don't really know what you mean by "what is the correct fuel air mixture setting?"

The only adjustment for mixture on these carbs that I'm aware of is the idle mix screw which you say you already know. The running A/F is preset by the sizing of the main jet, main nozzle and air bypass passage drillings in the main body. I'm sure Honda did the best they could to achieve a 14.7 air/fuel mixture which is known as stoichiometric (ideal) for gasoline fuel. There are undersized metering jets available for high altitude operation but they are only sold for the carbs built after 2001 or so as far as I know. I could be wrong about that though. But if you are operating under 3,000' elevation, there's really no need to worry about it unless you are experiencing overheat not associated with the cooling system. If the carb was modified for high altitude it would need to be re-jetted or it will run lean at sea level.
 
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