Fuel overflow

Still a noob to karting. My issue is… the fuel catch can fills every time… at least 120ml or more. There’s always fuel in the line connecting the bowl to the catch can. No matter if it’s at idle on stand, around the track, or testing on my property. The jet on/inside the bowl is stamped 180. Mikuni 34mm flatside on a kx80. Currently I have the fuel lines setup with a magic can

Is your needle and seat intact? The floats should close the valve completely when they rise the whole way up. If not, it’ll leak in up to the overflow. This assembly works the exact same way as a toilet valve does.

I’ll disassemble the carb tomorrow evening after work.
It’s almost like when I don’t check the catch can, everything is fine. But like everything else, once I know there’s an issue I have to fix it.

The standard way to approach it is:
1)Check needle, seat and float like Charles was saying
2)Make sure float level is set correctly
3)Make sure return line is not blocked as it can create backpressure
4)Ensure fuel pump is not the issue, delivering too much volume/pressure (rare, but can happen, testing with a spare helps)
5)Some carbs/setups tend do this at low rpms when warming up. Make sure you keep an eye on the vents as you warm up the kart, don’t just idle it…when warming up, aside for the first few seconds, you need to give it some good rpms

I’m not sure how to check, but can only guess… I dropped the bowl, left the needle in place and could not see the needle through the jet.

Maybe there was an obstruction in the float plunger keeping it from closing completely

Dissembled the carb and got something out from under the float plunger grove.

Also noticed the jet cap was on backwards, or… Which way is correct?

Are these jet sizes common for shifters.

That piece of crud was likely the issue…judging by the oxidation on the brass parts, it sat for a while…probably it’s time for a gasket set, needle/seat kit and the gasket underneath it…about $20 in total. A new float is about $10, I personally wouldn’t mess with testing, checking etc…throw away and replace with new, one less headache. As you clean the carb and replace those parts, clean the whole fuel system (lines, tank etc) and replace any inline filter

Bought the kart in sept off CL, replaced tank, all the lines, motor gaskets, seat, brakes, wheel bearing, Just haven’t replaced the carb and fuel pump gasket. Work in progress.
I’ll get that ball rolling. Is there any pros/cons with having the magic can? Or shall I delete that?

Since you have it already, keep it…it’s free insurance. Just give it a good flush to make sure there is no crud lodged in the cans and install the cans per instructions. Is it worth its price? Questionable, but since it came with the kart…The other thing, check the air filter. Is that an empty box with a filter outside or does it also have an internal filter as well?

Magic Can Set Up

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