Author Topic: float height adjusting on cb 750 k7  (Read 166 times)

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Offline kvikgrip68

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float height adjusting on cb 750 k7
« on: October 05, 2018, 10:31:46 pm »
hi everybody

i have the bowls off my carbs while the carbs are on the bike
now ...if i want to check and adjust the float heights … is it then done on the small "stop" piece of metal on each float ?
I can only find the Measurement 12,5 mm on the net but it seems all crazy ehen i measure on my floats they are lik 25 mm from carb flange to top of float meaured when they are "hanging" Down with bowls off
so either is something wrong or me not knowing where to measure :)

Offline pjlogue

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Re: float height adjusting on cb 750 k7
« Reply #1 on: October 06, 2018, 02:52:29 am »
The "stop" piece of metal on the float is to prevent the float from touching the float bowl bottom.  It should be set so the float is just off the bottom of the bowl.  The tang is what you bend (carefully) to adjust the float height for setting fuel height.  The tank pushes against the fuel valve pin.

For proper adjustment the carbs need to come off the bike.  The carb needs to be in a vertical position with the float acting like a pendulum with the pivot at the top.  You will measure from the bottom of the float (bottom as viewed when the carb is in normal operating position.) when the float tang (the part that pushes against the tiny protruding pin of the float needle) just contacts the pin is when you measure the float height.  The distance from the bottom edge of the float to the recessed seat of the float bowl (recessed seat is where the gasket sits against the carb body)  The float tang should not compress the pin into the valve at all, just touch it.  The set distance should be 28mm and make sure the bottom of the float is an even 28mm on each side of the float.

Once the base line float height is set you should do a clear tube fuel height test to be sure all bowls are set correctly.


Offline flybox1

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Re: float height adjusting on cb 750 k7
« Reply #2 on: October 09, 2018, 07:48:10 am »
Carb float height for the K7/8 is 12.5mm or 14.5mm...depending on carb model. 
Either way, a clear tube test should be completed after adjusting float tangs, to ensure correct fuel level.
Do it off the bike.  it only takes a few minutes, and you see if float heights are right.
Once adjustments are made, youre done with it....

'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

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