This is my first post here. Just acquired a 2007 trx450er. I put a new wiseco oem spec piston and rings in it to start. ( got it non running). Used the manual. Valves to spec, timing on. Checked everything more than once. It is bone stock. Stock exhaust. Uni filter. Air box lid on. Also rebuilt...
My exhaust valve stem measurements are barely in spec, but not at the service limit. I was wondering if I should replace them or just run them for another season.
Exhaust valve stem spec: mm(in)
Service limit: 4.96
Left exhaust: 4.966