carb tank vent problems

[aznighthawk]

i have 92 kat 750 been workin on her for awhile tank builds pressure dosent vent, also it floods after sitting for few minutes once get it going again runs good let it sit a min and its flooded

[hardlydangerous]

If it floods while sitting you need to replace the float valves.
also you need to address you fuel petcock on the tank, its either in then Prime position or the auto off valve is not working properly.

the tank vent is in the fuel cap,
the easy solution is buy a Vortex vented gas cap, or you can try to free up/unplug your OEM unit.

[Black_peter]

The flooding may not be the float valves.
Enough pressure can build up from an un-venting tank to over ride the valves.
The float valves are only designed to combat the pressure created by gravity.

Im not sure about the petcock. Do you mean that after it sits you start (or try to start) it and it floods? Or it is flooded right away? When you crank the bike your engine can create enough vacuum to open the petcock and flood the carbs.

I had my vent plugged up and when I disconnected the fuel line gas shot out of hose from the carbs..

[nealy212]

no stealling the thread but sometimes when i i park my bike whistleing is coming from my tank esp. when i have a almost full to full tank. is this normal?

[Black_peter]

Can you name the tune??

[Kreylyn]

Pictures and info of how the OEM cap works with where the vent hole is. Your stock one can be easily cleaned, most likely fixing the issue with the tank building pressure.

http://katriders.com/vb/showthread.php?t=102762

If you don't want to clean it, or wold prefer a replacement....

http://www.carbkitscapital.com/ has an OEM replacement for under $55 with 2 keys. Yes, you should be able to swap the lock right out so you don't have to swap them. Ebay the key and tumbler set and I'll bet someone would buy it back saving even more $.

http://www.carbkitscapital.com/carb_kit_list_model.php?make=Suzuki&model=GSX750

The petcock should stop the flow of fuel when the bike is off. Open the cap to prevent presure from building, and see if the bike is still flooding. If yes, then...

Check/repair the petcock as mentioned. Info on how it works and what the positons do...

http://katriders.com/wiki/index.php5?title=Petcock

Here is a full write up with pictures of doing a petcock rebuild...

http://katriders.com/vb/showthread.php?t=96553

Petcock rebuild kit is available from http://www.carbkitscapital.com for $21.



If your petcock needs rebuilt and you replace the cap, you could order them both and probably save on shipping.

If your floats are not preventing non presurized fuel from over flowing the carbs, then the floats may need to be adjusted, the float needles/seat may need to be cleaned, or the needles may need replacement. Do a full cleaning if what I would recomend, adjust the floats, inspect the needles, make sure it's all good. Replace any orings that are dried, hard, cracked, or otherwise not new and flexible looking.

How to on cleaning the carbs. Be sure to check out the PDF link at the bottom, same write up but with pics!

http://katriders.com/vb/showthread.php?t=63344

Krey

[aznighthawk]

The flooding may not be the float valves.
Enough pressure can build up from an un-venting tank to over ride the valves.
The float valves are only designed to combat the pressure created by gravity.

Im not sure about the petcock. Do you mean that after it sits you start (or try to start) it and it floods? Or it is flooded right away? When you crank the bike your engine can create enough vacuum to open the petcock and flood the carbs.

I had my vent plugged up and when I disconnected the fuel line gas shot out of hose from the carbs..

if it has sat a while it will start after running a while i shut it off and within couple min try to start it again and it wont start seems flooded.

i cleaned the carbs but was my first time with this style carb so am going to take back off and check them again using tips from the site.

[aznighthawk]

took them off again and adjusted the floats flipped them over and blew through the fuel line needles seem to seat and hold good.road it about a hundred miles ran good but didnt like to idle.sat few days rode it again and keeps flooding out.