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Honda BF20 do not rev up

S

Sarrre

Contributing Member
Hello guys,

One of my customers far away got some problem with his only two year old Honda BF20. It will not rev above half throttle. It starts easily and runs just fine at idle speed and slightly above. But when trying to accelearate it's acting like it's not getting enough fuel. He has taken the carb apart several times, but it is as clean as new. What do you suggest to try next?
 
The first point I wold look at is the accelerator pump. Take the air horn off and roll on the throttle. As you open the throttle, there is a lever on the outside of the carb that should push a strong jet of raw fuel back into the venturi throat. If that isn't happening, there's a blockage in the passages in the float bowl.
 
Send your guy the link below and have him remove items 3 and 4 from the engine oil dipstick tube. Item three is the "fuel chamber". Have him shake all the LIQUID out of it and then put it back and try the outboard again. If his problem is gone, then the chamber had a lot of water trapped in it. That chamber should be dumped out once a year because it can trap a lot of water from the fuel.

http://www.boats.net/parts/search/H...07 and Later/BF20DK3 SHA/FUEL PUMP/parts.html
 
Hi,
If it's a pull start, you have take the choke cable off the bracket and remove the carb with cable and knob still attached.

If it's an electric start, you need to unplug the bystarter electrical connector.

You then need to VERY CAREFULLY remove the throttle cable swivel socket from the carburetor throttle arm by "popping" it off the ball on the arm. If you don't take care doing that, you could break the throttle arm or the ball end. That would mean that you have to replace the carburetor because those parts are not available.

Then you simply remove the two bolts holding the muffler cover (item #4 in the link below)


Once the cover is off, you can then remove the two long bolts (items #8 in link) to take off the muffler plate (item 2) and carburetor together.

Good luck.
 
Thanks so much for the quick reply. I have the electric start (BF20DK3).

My issue has been removing the lower bolt holding the muffler cover (item #7 from the link above). There is no room to fit a socket and I can't seem to maneuver a wrench to loosen it. I did not start by unplugging the bystarter electrical connector or throttle cable. Would these two steps make it easier to reach the lower bolt?
 
Well, it's been so long since I removed one, I honestly don't know what to tell you other than the bystarter wiring or throttle cable have nothing to do with getting to that bolt.

I know it's pretty tight in there for sure! And no, a small wrench won't do. You have to figure out how to get a socket on it.

I'm pretty sure if you use a 10" "wobbly" end extension you can come in at an angle from the side to get on that bolt.

If you don't have a wobbly extension then you will probably need a wobbly socket since I don't think there's enough room for a universal joint.

It could be that a 3/8" to 1/4" adapter with a 1/4" short extension and socket could sneak in there too.

I'm not in a position to get to the one I own at the moment to figure that out for you or otherwise I would.

I can only offer that I'm positive it's "do-able".

But that bolt is dang tight so you will definitely need the leverage of a 3/8" ratchet or breaker bar to loosen it. A 1/4" ratchet or breaker probably won't work.

Sorry but that's all I got.
 
If that is the back section muffler cover (not the one with the little grill in it) then the lower bolt is tricky. I had my carb on and off maybe 6 times trying to clear the primary jet tube and eventually bought a new carb, However on the first dis-assemble I struggled and had to use an extension and a decent 1/2" ratchet drive so trying to put it on the first time after cleaning I just left the bottom bolt out and even with my new carb the bolt is in my spares box! Considering the underside of that muffler box is all open as an air intake having the bolt missing works great ! (I know it's not what you are supposed to do but sometimes you just have to stop struggling and skip the bolt)
 
Yes, for me it was the lower bolt on the muffler cover. Thanks to the advice above I was able to get it off and get the carb clean. Many thanks!
 
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