A.T.V (4-wheeler) Question
 

Hi,
03 LTX 400 will not start cold,
It has good spark
Pop the clutch and it will fire right up
once it is warmed up it will start no problem
Starting fluid into carb does not help
CDI and coil test good
what should I try next?

There's a lot of places to look.
Does it have a choke? If so, is it functioning correctly?
Fuel: You could have old fuel - Drain the fuel, and add all brand new stuff. Does it have an inline fuel filter? Or may want to pull the carb and clean it up good. Run some good fuel system cleaner through it and see if that helps.

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.

Thanks for the replays
Yes it is a Suzuki LTZ400
I do believe it is the values.
Compression test when cracking is about 40psi (way to low)
When I checked compression well trying to pop the clutch I had 180 psi
I rebuild the bottom end of the motor in July of this year
I replaced all case bearings, crankshaft, connecting rod, piston and rings.

The LTZ400 has an auto de-compression thing on the exhaust cam so I believe that is my problem. I will tear it down when I have some free time & money

make sure the auto decompressiopn is realeasing, the problem should be in the head (valvetrain) , starter motor, or stator. that the only things, other than the odvious bad gas as JT already said, i wouldnt use the injector clean stuff i would disassemble the carb blow out the jets with compressed air, clean everything up with B-12 carb cleaner.

For better help on the subject check out the forums on www.atvriders.com thats the largest and most helpful forum on the net for atvs. My username on there is the same as on here.

Thanks for the advice and I will check that forum out