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1975 kz400 petcock vent?

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04 Aug 2022 17:56 #871700 by jrider24
1975 kz400 petcock vent? was created by jrider24
Ive attached some pictures to show the set up that's on the bike now but im not sure if the previous owner did it right. The petcock does leak when its off but thats not a major problem and Im going to leave it till the winter to replace. However, the bike seems to have a hard time pulling gas sometimes. Im wondering if instead of having the two lines out of the petcock go straight to the two fuel inlets on the carbs if one is supposed to be the fuel line and split off to both carbs and the other is a vent line. However, both ends off the petcock let out a decent amount of gas so it makes me question this. Also the petcock only has ON, RES, and OFF. How would I prime it? Usually there's enough in the bowls but there was one time where there wasn't and it was a real pain. Thank you. 
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04 Aug 2022 20:07 #871704 by TexasKZ
Replied by TexasKZ on topic 1975 kz400 petcock vent?
That is a mechanical valve. It is hooked up correctly. When it is set to ON, fuel will flow, so there is no need for a Prime setting. The valve should be turned off whenever you shut the engine off.

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05 Aug 2022 12:30 #871731 by jrider24
Replied by jrider24 on topic 1975 kz400 petcock vent?
Is there any type of vacuum then? Because sometimes it has a hard time pulling gas and im not sure why. 

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05 Aug 2022 13:33 - 05 Aug 2022 13:35 #871734 by JR
Replied by JR on topic 1975 kz400 petcock vent?
Petcock looks like the type that works on gravity. Carbs probably have vents. Perhaps one of those black tubes? Gas tank should vent through the gas cap. These usually have a passage or channel through which air can vent through the key hole. If air cant enter gas cant exit. Open the cap next time you feel theres a problem.  Perhaps there is crud blocking inner workings. Bottom section with the nut cast into it should be removable so you can check for crud, water etc.

 

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Last edit: 05 Aug 2022 13:35 by JR.

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05 Aug 2022 13:59 - 05 Aug 2022 14:03 #871736 by Scirocco
Replied by Scirocco on topic 1975 kz400 petcock vent?
Remove the bottom filter cap and clean it!!!
 
 
Last edit: 05 Aug 2022 14:03 by Scirocco.

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