I did the Black Widow engine exchange and did the ported head option went with the most reliable engine build. Received it back about Thanksgiving last year but didn't really ride until spring of this year, it was cold last winter in CO. It has about 20-25 hours on it. Running Amsoil, changed engine and tranny oil every other ride.
I was an hour into a ride with a group of friends, bike was running great. Stopped at a fork in the trail to regroup so everyone went on right trail. Shut the bike off waited about 5 min. Group together and started bike no problem, 1st gear, clutch released and pretty sure it was fully engaged went about 20' and just started to open it up to climb a hill and a cerklunk noise and bike grinds to a stop. I pull in clutch and hit starter it turns once and then binds starter up. Bike will shift into neutral and was able to move it. So got bike pushed up to a road and back home.
Pulled flywheel cover and flywheel off and it is fine. Dropped engine out of bike and want to know where to start.