Author Topic: CB350F Floats not floating enough  (Read 1423 times)

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Offline pbz

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CB350F Floats not floating enough
« on: June 07, 2012, 09:14:56 PM »
Just got done replacing the float valves and seats and setting the float heights (to 25mm) to cure some leaky carbs. When checking the float height externally with the sight glass method the fuel level in the float bowls is about 2-3mm above the float bowl gasket. I haven't been able to get a definitive answer on what the correct level is, since I suppose there isn't one I suppose, since Honda never spec'd the fuel level this way. Seems like it should be below the gasket though, to minimize leaking. Does anybody have a good measurement for this based on a careful setup and say NOS valves and floats, seems like the closest we could get to an "official number".

The current level is after the bowls sitting with fuel over night, the day before, just after reinstalling carbs, the level was 2-3mm lower.

Seems there's no other conclusion other than that the floats are absorbing fuel and not floating as well as they should, and that I need to replace them. Recommend source for these? Would like to see that 'official' number if anyone has it.

Offline HondanutRider

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Re: CB350F Floats not floating enough
« Reply #1 on: June 08, 2012, 05:05:21 AM »
The current level is after the bowls sitting with fuel over night, the day before, just after reinstalling carbs, the level was 2-3mm lower.

Do you turn the petcock off when parking overnight?

Offline Deltarider

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Re: CB350F Floats not floating enough
« Reply #2 on: June 08, 2012, 05:43:25 AM »
You didn't put them in upside down, did you? Some people do. When put in, the look is different than the floats of a 500/550 for instance. You wouldn't be the first.
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Offline lucky

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Re: CB350F Floats not floating enough
« Reply #3 on: June 08, 2012, 11:30:52 AM »
Use a measuring tool and use the information in the book.
BUY a workshop manual.

"Floats not floating enough" LOL...lol...lol



« Last Edit: June 08, 2012, 11:40:15 AM by lucky »

Offline phil71

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Re: CB350F Floats not floating enough
« Reply #4 on: June 08, 2012, 11:47:38 AM »
are they brass?

Offline Deltarider

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Re: CB350F Floats not floating enough
« Reply #5 on: June 08, 2012, 12:45:32 PM »
Quote
are they brass?
Negative.
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Offline flybox1

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Re: CB350F Floats not floating enough
« Reply #6 on: June 08, 2012, 01:33:01 PM »
I haven't been able to get a definitive answer on what the correct level is, since I suppose there isn't one I suppose, since Honda never spec'd the fuel level this way. Seems like it should be below the gasket though, to minimize leaking. Does anybody have a good measurement for this ....
Per Hondaman, the optimal fuel level is 4mm below the bowl/carb mating surfaces.
24mm on my 350F's carb floats got me this level.  Mine never leaked once after this.
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bollingball

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Re: CB350F Floats not floating enough
« Reply #7 on: June 08, 2012, 02:59:53 PM »
I haven't been able to get a definitive answer on what the correct level is, since I suppose there isn't one I suppose, since Honda never spec'd the fuel level this way. Seems like it should be below the gasket though, to minimize leaking. Does anybody have a good measurement for this ....
Per Hondaman, the optimal fuel level is 4mm below the bowl/carb mating surfaces.
24mm on my 350F's carb floats got me this level.  Mine never leaked once after this.

I agree mine works best at 3mm below gasket. I never measure mine with a gauge clear tube method works great. 3 to 4mm seems to be the sweet spot
 Also Lucky that pic looks like the carbs are upside down I have never seen it done that way seems like it would compress the needle to much :o

Ken

Offline fmctm1sw

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Re: CB350F Floats not floating enough
« Reply #8 on: June 08, 2012, 05:07:32 PM »
Also Lucky that pic looks like the carbs are upside down I have never seen it done that way seems like it would compress the needle to much :o

Ken

Could have just been "for illustration purposes."  I usually have mine at about a 90 degree angle so the floats just rest on the needles.
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