78k overflowing out of #1 carb

bigj750

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I just took off my carbs to fix my accelerator pump. Got it to work finally but as soon as I put everything back on the carb overflowed. I took off the carb inspected the float/float height everything seems fine and also replaced the needle. Again it overflowed like Niagara out #1 carb what am I doing wrong?? It's never done this until I took the carb off to check the pump.


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amc49

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The entire pathway from petcock to the needle seat can be called that. Didn't think the idea was that hard to understand. Anywhere in there with a horizontal running component to form a shelf sediment can settle on. Move carb around, it stirs up and then runs into needle seat to block it open. If they use ethanol in your local fuel the particles can be so small they go right past any plastic filter Honda might use there, the pores being too big.

The problem not unusual, I've seen it personally more than once.
 

bigj750

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The entire pathway from petcock to the needle seat can be called that. Didn't think the idea was that hard to understand. Anywhere in there with a horizontal running component to form a shelf sediment can settle on. Move carb around, it stirs up and then runs into needle seat to block it open. If they use ethanol in your local fuel the particles can be so small they go right past any plastic filter Honda might use there, the pores being too big.

Sorry been working on the damn thing all day I'll have to clean out underneath thag seat and yes. I'm Chicago area all gas stations have ethanol. Any gas additive to counter balance that?


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amc49

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Nope, none at all. They say it will but it doesn't work.

Cars don't have much issue unless the evap system is leaking to vent it. Bikes though can have issues if you use fresh fuel and let the bike sit 2 weeks, then float issues show up. The carbs are way too open to the atmosphere and the ethanol then soaks water right up.

Ethanol is pretty transparent if the vehicle drives every day to keep fresh fuel in it, it's when the vehicle sits the problems really begin, a bike driven like once a week or so will soon show trouble.

I have fits with it in my CB550, paper fuel filter used in it catches the rust but the resistance of it can create fuel issues if I run the tank dry, it's slow to prime when refilled.
 

bigj750

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Nope, none at all. They say it will but it doesn't work.

Cars don't have much issue unless the evap system is leaking to vent it. Bikes though can have issues if you use fresh fuel and let the bike sit 2 weeks, then float issues show up. The carbs are way too open to the atmosphere and the ethanol then soaks water right up.

Ethanol is pretty transparent if the vehicle drives every day to keep fresh fuel in it, it's when the vehicle sits the problems really begin, a bike driven like once a week or so will soon show trouble.

I have fits with it in my CB550, paper fuel filter used in it catches the rust but the resistance of it can create fuel issues if I run the tank dry, it's slow to prime when refilled.

Right it's tough to find out here. Cleaned the inlet and everything works, guess I had to fully understand how the float and needles work together. Sometimes it's the simplest things that fix it.


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Steve 750

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I have an idea that seemed to work on my 78k I was able to take the float bowl off while #1 carb being mounted with short phillip screw driver. I pushed out float pin and removed the float and needle valve and sprayed up into the float seat on carb with carb and choke cleaner which will remove a small piece of trash or sediment. I never had any more trouble. Try to be patient and let the choke cleaner dry for a few minutes before assy of float and needle valve. Good luck Friend!
 

Steve 750

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78 k overflow I hope I did not confuse you, but this was done with the whole carb assy assembled on engine
 
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