Rings or valve seals?

[RedneckEX]

my bike's smoking a little on start-up (Fair amount of LIGHT blue smoke for a minute or two). Figure it to be oil, but am unsure if it is rings or valve seals. I assume that rings would be a consistent smoking, but have no compression tester to check that. It's the busy time of year for me, so I might have to have a shop do the rebuild. How much am I looking at for parts, and how many hours of labor, depending on the job? Thanks guys!
Allan

[greg_gorrell]

its hard to say but i would just buy both. i saw in a post on the c&d forum that the valve seals are only like $5 for 4 for a 400EX. mines been smoking when i let off the throttle so im just honing it and putting in a high compression piston while i have it apart along with the vavle seals. but yours is only doing it on start up?

[jak1389]

mine had the same problem. but it smoked some when i let off the throttle and then back on it hard. but it wasnt a constant smoking. well i am just making it a 416 and having lots of work done to it. if im in the engine might as well dod a little upgrades to it. everything thats going to be done is in my sig. i the cylinder is being bored and head ported and polished by c & d racing as we speak.