1984 Honda 7.5hp 4-stroke, won't idle after carb cleaning

[Callidus98]

My motor would start on full choke but when I closed the choke it would rev up and die. So I pulled the card and cleaned it. Now I can get it to idle a little longer when slowly closing the choke and reducing the throttle but I can't keep it running. Based on the exhaust, it seems to be running too rich. I have the motor on a stand with the prop off, in a bucket of water.

The manual calls for the pilot screw to be at 2.5 turns out. But doesn't describe the adjustment much.

What about the other screw in the top of the carb body? Right now I set this 'other' screw as snug tight.

Could these symptoms be caused by an air leak?

Thanks for any input.
Travis

After more reading on other threads, perhaps I didn't actually get my carb fully clean. A lot of other similar threads seem to say clean the carb again. So, with this carb there are not that many pieces, are there pieces that don't need to be taken apart to soak the carb? Besides the openings for the pilot screw and the other screw in the top are there other passages that I need to blow out after soaking?

You can probably tell that I am new to this, so any information is appreciated.

 

[brim_buster]

Re: 1984 Honda 7.5hp 4-stroke, won't idle after carb cleaning

If it idles up and then dies sounds like it running out of fuel. Hows the fuel pump?

 

[brim_buster]

Re: 1984 Honda 7.5hp 4-stroke, won't idle after carb cleaning

looking for a manual for it now.

 

[Callidus98]

Re: 1984 Honda 7.5hp 4-stroke, won't idle after carb cleaning

Thanks brim.

The fuel pump 'seems' to be working. Although, if it were not working fully I probably wouldn't know the difference. I pulled the manual starter with the fuel line from the pump to the carb disconnected and fuel was delivered and the fuel filter in that line appears to be staying full. I am not having to do anything to the bulb or fuel lines to get the motor to start again after it dies. Also, once started I can keep it running for a time with the choke half closed and the throttle still in the start position.

 

[brim_buster]

Re: 1984 Honda 7.5hp 4-stroke, won't idle after carb cleaning

did you adjust the idle air screw? I run them all the way in and back out 1 and 1/2 turns and play with it from there. Did you clean out the air bypass vents on top? might of got a piece of trash in there? Just giving you some things to look at.

 

[isaksp00]

Re: 1984 Honda 7.5hp 4-stroke, won't idle after carb cleaning

If it is like my 8HP BF8A, the screw on the top of the carb is not an adjustment - it is the low speed (idle) jet. You just screw it in snug. I have had similar troubles,and assuming the carb body has been cleaned thoroughly (read Paul's comments about use of real carb dip) it may be that jet. Remove it, and there is a tiny orifice up the center, and a few larger holes across the diameter. Just be careful you don't drop it in the water. Then clean the center orifice. I use a very thin stiff plastic "wire", that I get by splitting a floss threader (go to any drug store). Then I spritz with carb spray. That seems to improve idle ability dramatically, and I have to repeat it every so often. And I do disconnect the fuel line and let the engine run until dead, every time I dock.

 

[Rick Stephens]

Re: 1984 Honda 7.5hp 4-stroke, won't idle after carb cleaning

I bought a paper version of the manual for my 10 HP. Might help you. Nice manual, if expensive at $40 from Honda.