Fuel Carb Full (1 Viewer)

dannyvp

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I just reassembled my head, gasket and cooling system on the truck.
When I put my carb back on (Fuji carb) it will not time out with the lean drop method. The idle speed screw will adjust the RPM, but the fuel mix screw will NOT adjust the RPM’s.
I check the site glass and the fuel is all the way at the tip top of the glass.
This is a new carb. Less than couple hundred miles on it.
The vacuum is around 18-20.

suggestions on next steps?
 

g-man

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If your fuel bowl is full the needle valve and seat are not sealing when the float comes up. Or the float is stuck in the down position or the float is cracked on not coming up.
 

dannyvp

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Roger (city racer) posted about this. Sometimes the float needle gets stuck because the boxes get flipped in transit. Tap the top corner GENTLY with a non-metal mallet and see if it frees the needle.

do you know which corner to tap, and how to tell if it works?
 

dannyvp

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Well I drained the fuel from the access ports, tapped the top of the carb.......
Now I see no fuel in the carb window when it’s running.
I’m trying to tune the carb and when I adjust the fuel mix screw. Nothing happens.
 

Pighead

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So, in the last couple hundred miles, have you ever been able to lean out the carb to lower RPM? (is this a new problem or an older problem?)
Me, I would take the top off the carb and take a close look at the float, see if it moves up and down without binding on something. Maybe remove the float, put it in some water, see if it floats. Examine the needle valve for movement and debris. If that all looks good reassemble and check the range of motion of the float. Adjust the tabs on the float if out of whack. Put the top back on and see if you fixed it...
 

Spike Strip

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You sure bowl is empty and not just at the top?

When sufficient fuel is in the float bowl, the needle will close, this is about half-way in the sight glass. If there is no fuel in the bowl, then the needle is sticking closed. If it's over-filling, then the needle is stuck open.

Did you tap the corner of the carb with the engine running? Tap it rapidly, but not too hard. You're just trying to create enough vibration to free whatever corrosion has made it sticky.

But Pig is right, prolly time for the top to come off and see what's what.
 

dannyvp

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Spike you are correct. Its so full you cant see a bubble or line.
I have not taken the top off bc its new. I did however tap the top and nothing happened. I did that with the engine not running though. I'll start it and see what happens.
 

dannyvp

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So, in the last couple hundred miles, have you ever been able to lean out the carb to lower RPM? (is this a new problem or an older problem?)
Me, I would take the top off the carb and take a close look at the float, see if it moves up and down without binding on something. Maybe remove the float, put it in some water, see if it floats. Examine the needle valve for movement and debris. If that all looks good reassemble and check the range of motion of the float. Adjust the tabs on the float if out of whack. Put the top back on and see if you fixed it...

So i just replaced my head gasket, before that when i put the carb on i had lots of problems, some not the carbs fault.
 

Spike Strip

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Is it doing this (squirting gas out the vents?)

This is also a Fuji carb where Roger recommended he tap the corner and it fixed it.


 

Racer65

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I'm not seeing a stuck float nor any resulting symptom like that in the Weenie 3 video. Gas appeared to spray fine in the prior video.
 

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