A.T.V (4-wheeler) Question

[rootar]

are you talking about a suzuki z-400??? ive never heard of an ltx 400.....

you might need to bump up a size or two on your pilot jet, sounds like its not jetted right if you have to "pop" start it. you can do a compression check and also check your vavles, the exhaust vavles being out of spec will make it near impossible to start, the intake being out of spec will cause some issues also .

i race MX on quads and build my entire bikes myslef, let me know if its the valves, id put my money on that or its just wore flat out. i had a motor 6months back that didnt smoke or anything and one day you just couldnt kickstart it, but you could pull start it.... tore it down after changing and testing everything outside of splitting the case and you could nearly drop the piston through the cyclinder with out compressing the rings. The jugg and piston were trash.