Hello. I'm new to site and recently purchased a 2001 Trailblazer 250. I was told the bike was only rode around in a yard by young girl. Appears to have approx 20 hours by the looks and condition of tires and such. After taking bike out to ride once the motor got hot after 20 minutes riding I'm getting a rod knocking sound. I was told it may be the clutch buttons. After taking clutch off I took it to dealer and they said buttons weren't worn enough to be making that noise. It seems to only do it between 1/8 and 1/4 throttle. Couldnt find any play in crank while clutch was off. Any help or suggestions would be greatly appreciated. Thanks so much. Harleypap

 

CHECK FOR AIR LEAKS ,sound like pre detination (spark knock to me)..my 99 did that

 

I have had the piston pin bearing get wore and do that.I would ride it until it is time for a topend and go from there

 

Thanks alot for the idea's. I will check into them. Thanks again.