I am reasonably sure that the puff of blue smoke on start (or after at least a ~30 min rest) indicates an issue with deteriorating valve stem seals. The actual seals are cheap, but are they "easy" to remove/replace? I can't seem to find any DIY info on their extraction/replacement. Where is a good place to get the tools? I think at least two specizlied seal tools are needed. If it's not a good idea to attempt oneself, can anyone give me a reasonable labor estimate (in hours) so I can budget? Thanks!