Carb probs again!

[79fordblake]

Well on my 81 185s I thought I had the overfueling problem fixed. Changed down to a 90 main jet and cleaned carb good. Ran great, no smoke, great throttle response, no bog at of idle throttle, plug looked pretty good.

I was riding it today and it all went down hill from there. Started smoking again, the bog at off idle throttle came back, sometimes doesnt want to idle, plug is jet black again.

I dont know what to do, hotter plug maybe? Fuel filter maybe not doing good enough job and parts getting clogged up? If I ride it hard and full throttle it it will clear up but if it idles or I just cruise around it loads back up again(and I like to just cruise alot, not balls to the walls). I run 93 octane fuel in it and it has a Autolite 4164 plug. What would be a hotter plug?

[Yamaha_Rules69]

The fuel filter would not have anything to do with it running rich. You dont normally want to run a hotter plug unless for a last resort kind of thing, as it could burn a hole in your piston. The NGK plugs are generally a better plug, and thats the plug I would recommend. Running rich could be a few different things. Is your air filter clean, or soaked in oil and dirty? Check to be sure the choke isnt stuck halfway or all the way on, take the boot off from the airbox to carb and move the lever up and down and visually inspect it. Next, did you try turning the air/fuel screw on the bottom of the carb inwards, which would make it run leaner? Last, it could be your float level set too high, forcing the jets to be sucking too much fuel. If you need, look up a manual for the specs for what to set things like the air/fuel screw (stock), and float height. Good luck, and hope this helps.

---------- Jon.

[Thorpe]

probably got a little piece of crud stuck in your needle and seat in the carb... Exactly what my BR was doing...

[79fordblake]

The fuel filter would not have anything to do with it running rich. You dont normally want to run a hotter plug unless for a last resort kind of thing, as it could burn a hole in your piston. The NGK plugs are generally a better plug, and thats the plug I would recommend. Running rich could be a few different things. Is your air filter clean, or soaked in oil and dirty? Check to be sure the choke isnt stuck halfway or all the way on, take the boot off from the airbox to carb and move the lever up and down and visually inspect it. Next, did you try turning the air/fuel screw on the bottom of the carb inwards, which would make it run leaner? Last, it could be your float level set too high, forcing the jets to be sucking too much fuel. If you need, look up a manual for the specs for what to set things like the air/fuel screw (stock), and float height. Good luck, and hope this helps.

---------- Jon.

I meant maybe the filter isnt getting all the trash out of the fuel. I've done everything you said except check float height. I figured float height was ok since it doesnt always overfuel. I will check though.

[hairytriker]

You said it right there fella, it doesn't always overfuel... Most likely will be a bit of crud in the float needle or perhaps (and I've seen it on a few bike carbs) the float itself is binding on the pin occasionally & could do with it's pivot holes cleaning.