alright lets see if anyone gave shine some light on this subject, I have all my fellow techs stumped.
customer brings me a rubicon that sat and carb was replaced.
few months later he brings it back complaining of it cutting out and dying. so here goes!
this is what I've checked
compression- within spec.
valve lash - within spec.
tank is clean
petcock is new
fuel line is new (clear so I can watch)
new inline filter
air filter is clean
gas cap is free flowing
carb is new and I've cleaned it anyways. float valve is clean, not a spec on it.
and I haven't lost spark at any time.
machine runs like It should but on high load/speed I can drain the float bowl faster than it can fill. cuts out dies.
bowl is empty - as seen on my float gauge and the fuel line will go empty!!!! I pull line off and fuel flows totally unrestricted. I can blow air up into tank or down thru tank either directions I have no restrictions.
made sure float isn't sticking closed but it acts like it.
im creating positive pressure somewhere. all engine vents are clear along with carb vents.

im lost. fuel line should stay constantly full but it doesn't until I break pressure and remove it from carb gas inlet and it comes flowing like normal.

quad runs until fuel height becomes low. obviously

stumped

I can run it dry, blow on a vent on fuel inlet and it will fill, till the float closes and then it will never reopens. does same thing with two oem carbs.

im overlooking something please help lol