so heres the deal...i have an 03 z400
it has spark and gets fuel but wont run.
if i spray fuel in the carb it will run till that fuel burns and then quits.....i am thinking valves are bad, also revs real high when started with gas sprayed into carb.
i have all new valves / piston and rings
any special tools needed to replace the valves ( how do they come out).
im not sure if this is the problem but these were in cluded when i bought the atv so i have them anyway.....
i am very greatful that you guys are here to help us rookies

 

I think you have a carb problem not valves. sounds like a plugged jet, if it runs on gas sprayed in it then its a carb probem. and check the fuel petcock for dirt. the 03 had problems plugging up and not work right... to remove the valves you have to remove the head and the cams and then you need a special valve spring compressor to remove them, its cheaper to have a shop do it than to buy the tool

 

thats what i thought at first however i have cleaned the carb and also used a carb off another z400 ( same year ) and it still will not start as if there is not enough compression to suck the fuel into the cylinder? i dont know im baffled

 

have you run a compression test on it yet? should be around 140
if its low it could be worn cylinder/rings, valve adjustment or timing, damaged piston

 

an another thing about valves, if you replace them they have to be seated to the valve seat and have the valve lash readjusted if you do that you might as well have the head cleaned and new seals, thats when a good shop comes in handy