mine and a buddies have been pretty much rock solid
mines an 850, 5lb spring, prem/a little avgas for safety
only had one day where i had issues, but i dont think that was due to the kit, fresh plugs seemed to fix it, pulls hard, TRS clutching
buddies is an 850, 10lbs, cant remember his fuel ratio,
his is always spot on as well, goes through reeds occasionally @ 10 lbs tho, garage maintenance item
i'd say if you run 5 or 7 lbs theyre pretty "maintenance free" other than the usual stuff. I look mine over well before and after each ride
went on a 10 day trip last year, multiple riding spots/elevations and it never had an issue
i think im going to bump up to 7lbs this year