Motorcycle Repair: Honda cr 80 will not start, honda cr 80, shively

Question
My son's 2001 CR 80 was running in 6th gear around 40 mph. when it shut down. I pulled spark plug and in was not only fould but the gap was smashed down. I have spark with new plug. do I have to do a top end repacement at this time.
thanks.  

Answer
Hi John,

You'll have to investigate why the gap closed.

Check if the engine partially siezed or if the piston touched the spark plug electrode.

You should consider pulling the head and cylinder and inspecting parts for evidence of defects and damages.

Respectfully,
Mark Shively