Carb leaking gas, Engine backfiring

[Sambo2132]

My carb keeps overflowing with gas, and pouring out of every hole. I have replaced the O-rings but havent tried a full rebuild kit, wanted to see if anyone had some ideas first. The only changed I have made were to where its at. I put the engine on a mini bike instead of a go kart and un mounted the gas tank so its higher, not sure if that might have anything to do with the pressure but I doubt it. I have a vm22 Chinese mikuni.

Now for the 2nd problem, the backfiring. Before this whole gas thing and even now if I take the carb off and use starting fluid it always backfires. I have put new cam in, chromoly push rods, 26 lb valve springs and checked my valve lash god knows how many times. Ignition is advanced by 4 degrees also. I have tried using stock cam and no ignition timing to no prevail. I have heard that with high compression (I have thinner head gasket and extended piston rod 0.040") I believe its because of compression but again if anyone has ideas I would like to still be able to pull start it, havent found any reasonably priced starter kits.

 

[Denny]

It sounds like your needle and seat are not sealing. You may have dirt in them, stuck needle or miss adjusted or heavy float.

 

[Sambo2132]

Ok thank you, found a carb rebuild kit for 11$ for the VM22. Gonna try that and hopefully solves that issue. Gonna get higher rater head studs and a better head gasket im running high compression I honestly dont even know the exact ratio. Just know a 0.040 rod with 0.016 head gasket and everything else is stock looking at at ported and decked head though for a little more. Keeps backfiring I believe its cause of compression its just so much gonna set back ignition timing and fix carb and see how it does.

 

[madprofessor]

That carb would never be receiving all that gas to pour out of itself if the inlet needle valve were mating up to its seat. If the needle isn't perfectly seated, dear ole gravity will keep pouring more gas into the float bowl, and the poor drowning carb will keep leaking all that gas out.