Author Topic: Float valve replacement  (Read 1101 times)

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Offline sharpinski

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Float valve replacement
« on: May 27, 2013, 08:02:59 AM »
Moving along on my rebuild, but I have a bad float valve. I recently posted about idle jets for a CB750K8 and was able to locate those (with the help of this forum). I was wondering if anyone knows if and where they are available. I checked the sirius consolidated sight and didn't see them. I'm contacting them as well. Any help would be great. Thanks

Offline flybox1

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Re: Float valve replacement
« Reply #1 on: May 27, 2013, 08:44:11 AM »
yes, they are available.  Replace all of them, as a set.
Cb750 supply
Partsnmore
Performancewarehouse
Take your pick.
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

Past Bikes
1974 550K0 (stock), 1973 CB350F (stock), 1983 Yamaha XS400K (POS)
77/78 cool 2 member #3
"Knowledge without mileage equals bullsh!t" - Henry Rollins

"This is my CB. There are many like it, but this one is mine…"

Offline 750K

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Re: Float valve replacement
« Reply #2 on: May 27, 2013, 09:09:00 AM »
Do you mean float needle, float needle seat or float itself?
77 Cb750, 78 Kz1000

Offline sharpinski

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Re: Float valve replacement
« Reply #3 on: May 27, 2013, 03:10:14 PM »
Thanks again flybox. You've been a great help

Offline sharpinski

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Re: Float valve replacement
« Reply #4 on: May 27, 2013, 03:12:53 PM »
To 750: it's none of those. It's the part that the seat goes into. I know it as the float valve, but maybe I'm wrong on that.

Offline 750K

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Re: Float valve replacement
« Reply #5 on: May 27, 2013, 03:21:10 PM »
The seat or what the float needle goes into is pressed into the body of the carb on the 77-78 pd's. So I'm not sure what it is you're referring to. Got a pic of the part?
77 Cb750, 78 Kz1000

Offline sharpinski

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Re: Float valve replacement
« Reply #6 on: May 27, 2013, 03:40:54 PM »
It is exactly the pressed in part

Offline sharpinski

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Re: Float valve replacement
« Reply #7 on: May 27, 2013, 04:12:11 PM »
Just for clarification. The float needle and seat are one part as I understand. The float valve is the brass part in which the float needle and seat goes into to stop the flow of gas. A 1978 CB750K has PD carbs. On those carbs the float valves are pressed in not screwed in. I'm looking for pressed fit or friction fit float valves if available. Flybox, Cb750 supply and Partsnmore carry screw in types, but i don't see press fit ones. Tomorrow I'll contact Performancewarehouse to see what I can dig up.

Offline flybox1

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Re: Float valve replacement
« Reply #8 on: May 27, 2013, 05:13:03 PM »
Tell us why you think, or how you know the needle seat is needing replacement? If its the press fit type, I don't believe they are available. it came as part of the carb body. 
Its a brass part that won't see wear as the float valves are rubber tipped. They seldom fail if it uses the rubber tipped float valves.
If it's corroded, clean it, add a new rubber tipped valve, and call it good.
« Last Edit: May 27, 2013, 05:56:06 PM by flybox1 »
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

Past Bikes
1974 550K0 (stock), 1973 CB350F (stock), 1983 Yamaha XS400K (POS)
77/78 cool 2 member #3
"Knowledge without mileage equals bullsh!t" - Henry Rollins

"This is my CB. There are many like it, but this one is mine…"

Offline raymond10078

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Re: Float valve replacement
« Reply #9 on: May 27, 2013, 05:30:35 PM »
According to the Honda parts fiche, the float valve is what you are calling the needle.  You're talking about the part that most call the seat.

What makes you think that the seat is bad/needs replaced? 
1978 CB750A (upgrading very, very slowly)

Past bikes - Honda: SL350, CX650C, CB900C, CB1000C, CM450A; Kawasaki: several 1972 750 H2's; Suzuki: TC90J.

Bikes I want: CX650ED, a mid-sized japanese V-twin with ABS.

Offline 750K

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Re: Float valve replacement
« Reply #10 on: May 27, 2013, 09:45:28 PM »
The pressed in seat is not available as far as I know, it's part of the carb body as flybox said. The tip of the needle is rubber so the seat shouldn't have any wear unless there's corrosion of some kind.
77 Cb750, 78 Kz1000