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Carb settings cb400f with 4-2 exhaust
Laverda Dave:
Float height should be 21mm. The Haynes manual is incorrect as I found out to my cost when the carbs overflowed! Thanks to the helpful people on the forum who know the correct measurement.
Sounds like it's going well though.
Chris400F:
--- Quote from: Erwin83 on November 23, 2016, 10:22:24 AM ---Unfortunately the Taiwanese O-rings for the float cups seem to grow in size. I think I read something similar about the Keyster kits (brass parts OK, rubber parts NOK).
--- End quote ---
I know various people have had a bit of fun fitting these O rings when using the Cruzinimage kit as they are not shaped.
A dab or two of sealant to hold various points in place seemed to help, and I seem to recall warming the rings to help soften them may also have been mentioned.
Erwin83:
--- Quote from: Laverda120 on November 23, 2016, 02:14:28 PM ---Float height should be 21mm. The Haynes manual is incorrect as I found out to my cost when the carbs overflowed! Thanks to the helpful people on the forum who know the correct measurement.
Sounds like it's going well though.
--- End quote ---
For some reason, I really needed to go to 23mm to get the float needles to work properly. 22 (or 21) didn't work well and made the carbs drip.
Just pressing the floats down (carbs inverted) I found that with 22 mm float height, the float hits the housing bottom before the needle fully closes the fuel flow (easily checked with compressed air). Of course that is with max compression of the little needle spring...
If it weren't for the huge amount of extra work, the best solution would be to do an actual check on the fuel level.
I guess (but I can't explain it) that the buoyancy of the floats may have reduced due to old age?
I tried 'em in the sink though, they all float the same way (height) in water... None of them seemed to be leaking.
Now, I hope my fuel mixture is not influenced to much by the possibly 1-2 mm lower fuel level.
Erwin83:
--- Quote from: Chris400F on November 23, 2016, 02:45:33 PM ---
--- Quote from: Erwin83 on November 23, 2016, 10:22:24 AM ---Unfortunately the Taiwanese O-rings for the float cups seem to grow in size. I think I read something similar about the Keyster kits (brass parts OK, rubber parts NOK).
--- End quote ---
I know various people have had a bit of fun fitting these O rings when using the Cruzinimage kit as they are not shaped.
A dab or two of sealant to hold various points in place seemed to help, and I seem to recall warming the rings to help soften them may also have been mentioned.
--- End quote ---
Fresh out of the box, they fitted perfectly, even though they are unshaped.
However after 2 days fitted on the carb, they seem to get longer, maybe unsuitable material for use in fuel environment..?
I actually cut 2 of them and decreased the lenght by 3-4 mm to get them just right again.
I'm hoping this O-ring to U-ring conversion won't cause a leak, otherwise I'll have to get new seals.
Tomb:
I usually treat the o-ring getting fuel on it making it swell as a sign that the fuel level is too high, As the fuel level should be lower than the bowl mating face, in an ideal world we shouldn't need an o-ring. For this reason I rarely replace the 0-ring.
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