Author Topic: Leaky #3 float driving me insane!!!  (Read 4701 times)

0 Members and 2 Guests are viewing this topic.

Offline Magilla

  • Expert
  • ****
  • Posts: 764
  • My bike: 1976 CB750F
Re: Leaky #3 float driving me insane!!!
« Reply #25 on: October 03, 2012, 05:48:11 AM »
First off they should make a clear bowl cover that could be used for testing these things.  How nice would that be?  Secondly, does it do it when it's running or when it's sitting?  Believe it or not these things tend to overflow while sitting with a full tank of gas.  The weight/pressure can sometimes push the gas past the float needle.  I went crazy chasing this issue. 
1972   Honda CB350
1972   Yamaha 500
1982   Yamaha 650
1988   Harley Sportster 883
1983   HD FXR Shovelhead
2003   HD Heritage Softail
2006   Victory Vegas Jackpot
1980   Honda CB650
1976   Honda CB750K
1982   Honda CB750
1964   Honda CA95
1982   Kawasaki 550
1974   Honda CL360
1975   Suzuki GT550
1981   Honda CB750
1981   Honda CB750
1970   Norton Commando
1972   Yamaha U7E
1970   BMW R50/5
1976   Honda CB750F

Offline Terry in Australia

  • Really Old Timer ...
  • *******
  • Posts: 33,302
  • So, what do ya wanna talk about today?
Re: Leaky #3 float driving me insane!!!
« Reply #26 on: October 03, 2012, 05:56:39 AM »
I think I'd just get another set of carbs............ ;D
I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

"Crazy is a very misunderstood term, it's a fine line that some of us can lean over and still keep our balance" (thanks RB550Four)

Offline lucky

  • Really Old Timer ...
  • *******
  • Posts: 6,717
Re: Leaky #3 float driving me insane!!!
« Reply #27 on: October 03, 2012, 09:40:03 AM »
New seat and new needle. That is what I would do.
Actually I would put in all the seats and needles and set the floats by the BOOK.

End of problem.

Offline tlbranth

  • Master
  • *****
  • Posts: 1,659
Re: Leaky #3 float driving me insane!!!
« Reply #28 on: October 03, 2012, 10:12:59 AM »
New seat and new needle. That is what I would do.
Actually I would put in all the seats and needles and set the floats by the BOOK.

End of problem.
......unless the float tab sticks on the needle
Don't own a Vanagon
Don't work at Boeing
Life is good

1970 CB750 K0
1975 GL1000
1999 GL1500
2002 VT750-CDA ACE - Momma's bike
Terry

Offline 750K

  • Expert
  • ****
  • Posts: 1,392
Re: Leaky #3 float driving me insane!!!
« Reply #29 on: October 03, 2012, 10:51:47 AM »
I think I'd just get another set of carbs............ ;D

Come on Terry, where's the fun and challenge in that haha.

Lucky, you should know this. PD's have a pressed in seat and I have brand new needles in there.
77 Cb750, 78 Kz1000

Offline 750K

  • Expert
  • ****
  • Posts: 1,392
Re: Leaky #3 float driving me insane!!!
« Reply #30 on: October 05, 2012, 06:49:40 PM »
Where the needle valve contacts the float tab, is there a dimple? If there is, file the tab 'til the dimple's gone or fill the dimple with solder and file smooth. Then see if it leaks.

I think you nailed it, all 4 tabs had a good dimple where the needle touched. The ones in my spare carbs had almost no dimple, I filed them smooth and polished them with my dremel. I've tested twice and no leaks so far, just have to adjust #1,3's levels a touch and re test a couple more to be sure. So far it looks like the problem.

Thanks everyone for all the advice, much appreciated! Always good to have other peoples ideas, when crossing things off the to check list ;)




Edit: problem fixed, I even swapped to og floats back in after filing off the dimple. #3 is now holding a nice stable fuel level as the rest of them. Real happy, now tuning for the new airbox setup. Thanks again for the help.
« Last Edit: October 05, 2012, 09:29:44 PM by 750K »
77 Cb750, 78 Kz1000