not a honda but

[GAZ-V-21]

Alright guys my bro in law just bought a 2003 suzuki z400 the other night for a good deal. It is kind of hard to get started even with choke on but when it starts it runs like a champ UNTIL we would get it up to high rpm it will cut off. Does this sound like a carb/jetting issue?

[rooster300ex]

Sounds more like a valve issue to me. JMO

[81dasher81]

try going up one or two sizes on the pilot jet, it should help get it started when its cold.. cutting out could also be in the main jet, i would go up a size or two and work from there.

[GAZ-V-21]

Alright ill have him grab a couple jets this week. What kind of valve issue might it be?

[81dasher81]

they might not be adjusted properly, when there is too much valve lash, the valves open slightly too late, and close slightly too soon, shortening the time they stay open.. basically it chokes it off by not giving it enough flow.

[Rip_Tear]

Definitely check out the carb first, but you really do need to check the valving on the Z400's. I know a lot of people don't check them or do them wrong, they aren't like the valves on the 400ex, you need to shim the valves not just adjust the screw/bolt set up like a 400ex.