Old Honda BF75 with points and condenser.

[Dave-R]

I bought a old Honda BF75-100 ish outboard. After putting the right plugs in, I got it to idle okay. But when I give it any throttle at all it bogs down. I have cleaned the points, and set the gap at TDC, and cleaned the carb also. The compression is good. The carb seems to be getting plenty of fuel. I even pulled the fuel pump and cleaned the strainer. Any thoughts on this ? I also replaced the impeller and it's spitting more air than water out the tell tale, guess I either have a blocked tube or never got into the tube when I put the lower leg on. As always your help is appreciated. Dave-R

 

[pvanv]

Sounds like the carb needs to be cleaned. Properly. Also sounds like you are not pumping properly.

 

[Dave-R]

Paul : That is what I thought also, but I really cleaned all the ports and orifices with a tiny set of orifice bits. I kinda ruled out the fuel pump, because when idling I can open the bowl drain and get fuel to come out . It does sound like a fuel issue, but I did not want to rule out the timing possibility, or something to do with the points. Dave-R

 

[pvanv]

Never, ever, put a drill bit anywhere near a carb. Even if successful in opening a jet, the resultant swirl marks will cause weirdness in the mixture at some velocities. That carb needs to be fully disassembled and soaked in carb dip overnight, followed by a liberal blow-out using generic acetone based carb spray, and then a careful reassembly. Yes, you could have other issues, but odds are the passages in the carb are varnished.

 

[racerone]

On more than one occasion have we seen folks struggle to get these carburetors clean.-----Sometimes on the third or fourth try it works.

 

[Alumarine]

On more than one occasion have we seen folks struggle to get these carburetors clean.-----Sometimes on the third or fourth try it works.

I have the t shirt.

 

[rayjay]

Whenever you have a lean condition like this try giving it a bit of choke progressively. If this clears it up then you are definitely lean.

 

[Dave-R]

I got it. I convinced myself that the carb was clean as a whistle. So I went back to the points, and adjusted them ever so slightly to open just a few degrees earlier, and she now runs great. Good throttle response and no bogging. On the water side I pulled the lower and upper leg to blow out the cooling tube, pulled the thermostat, and cleaned all the pipes, going in and coming out of the engine. The tube to the tell tell was packed solid with what looked like toilet paper, as was some of the ports. It was an interesting repair, and thanks to all who posted to help me. As for the drill bits I used to clean the orifices, I did not use a drill motor, making sure I was careful not to ream them. Thanks again Dave-R