I have been researching, and have found that the 450SX's use Titanium valves starting in 03, but I guess the 03 525SX did not get these. The 525 is same displacement as the 520 was, but the 450 is a bumped up 400. Most probably knew this, but is news to me
But there are changes to the 03 525 to improve relibility, such as lighter valve springs, crank, diff cylinder head, larger ports, lighter ignition system and ?
Is there any preventive items I can do, or look for signs of future trouble?
If clutch plates break, what are the symptoms.