Author Topic: Solution for float level adjustment vexation (?)  (Read 3328 times)

pullshocks

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Re: Solution for float level adjustment vexation (?)
« Reply #20 on: March 22, 2014, 08:45:26 PM »
Well, not out of the woods yet.

Reassembled the bike.  On the center stand, not side stand.  Tried to start.  Fuel came gushing out the overflows.

Took the tank and air box back off.   After trying a few things, I believe what is happening is the float is hanging up on the drain tube.  The foam is shaped to provide clearance around the tube, but I can see that the float is slightly angled in a way that would bring it closer to the tube. 

I hope I can bend the hinge to overcome this.

pullshocks

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Re: Solution for float level adjustment vexation (?)
« Reply #21 on: April 07, 2014, 12:00:34 AM »
Back in the float valve laboratory today.  Came up with a way to manipulate the float from outside the carburetor.  Ran a fine wire through the vent hole and tied it to the metal part of the float.  A gentle tug on the wire lifts the float.
With the carb reassembled you can hear the float moving as you  gently pull on the wire.  This verifies the float is moving inside the carb bowl.

pullshocks

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Re: Solution for float level adjustment vexation (?)
« Reply #22 on: April 07, 2014, 12:25:52 AM »
So that test ruled out the theory that overflow was caused by the floats jamming in the bowls.

With that established it was back to the transparent carb bowl simulator.

What I observed was sometimes the valve closed, sometimes it didn't.  Very inconsistent.  When it worked, the float seemed to develop its buoyancy with about 80% below the fuel level, 20% above the fuel level.   Other times, the float would be completely submerged without shutting off the fuel.

After changing to fresh fuel, adding an in line filter,  and blowing compressed air through the valve, performance became consistent.

Conclusion:  it does not take much contamination to prevent the float valve from closing.

I reassembled the bike.  No more overflow at idle------ YAYYYYY!

Bike runs but needs an idle adjust and synch.


Rikugun

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Re: Solution for float level adjustment vexation (?)
« Reply #23 on: April 07, 2014, 08:11:58 AM »
Conclusion:  it does not take much contamination to prevent the float valve from closing.
No truer words have ever been spoken.....

Congrats and here's to continued leak-free times.  :D
It is far better to grasp the universe as it really is then to persist in delusion, however satisfying or reassuring.  Carl Sagan

QBS

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Re: Solution for float level adjustment vexation (?)
« Reply #24 on: April 09, 2014, 12:15:52 AM »
To clean debris out of a float needle valve: remove main fuel line from carb....attach short piece of separate gas line to carb......open carb drain screw.....tap side of float bowl to ensure float drop.....fill large syringe or reasonable facsimile with gasoline or carb cleaner........stick output end of syringe into short fuel line.....forcefully inject gas in syringe into gas line.....repeat several times.....reconnect main fuel line to carb.......close drain valve........turn petcock to PRI......check for leakage.

pullshocks

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Re: Solution for float level adjustment vexation (?)
« Reply #25 on: April 09, 2014, 10:02:49 AM »
Great suggestion, QBS.

Jirik

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Re: Solution for float level adjustment vexation (?)
« Reply #26 on: April 13, 2014, 02:49:02 AM »
Great topic, thanks for it.
What do you think about this advice https://www.youtube.com/watch?v=P0egD-1XWN4?
That is a little brutal for float valve spring, but it probably works.

fret not

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Re: Solution for float level adjustment vexation (?)
« Reply #27 on: April 14, 2014, 12:58:37 AM »
Yes, a bit brutal to the little spring.  It is toast, literally.  When most metal glows that bright is has no temper remaining.
Retired, on the downhill slide. . . . . . . . still feels like going uphill!

Rikugun

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Re: Solution for float level adjustment vexation (?)
« Reply #28 on: April 14, 2014, 08:26:23 AM »
While I'm cleaning the carb bodies I soak all the brass bits in a small container of solvent. This generally will free up a sticky, varnish laden inlet needle damper. If rubber tipped, you may want to limit exposure but non rubber tipped can be soaked at length.

It is far better to grasp the universe as it really is then to persist in delusion, however satisfying or reassuring.  Carl Sagan