hey guys i have a 2002 honda 400ex and the other day i was riding and the bike shut off and wouldn't crank anymore. spins over like it was out of timing. so i tore it down redid the timing and the bike cranks right up but has this knocking noise in the bottom end when cranking. after the bike runs for about 2 mins or so the timing chain comes off in the bottom end of the motor. tore it down again put the chain back on start the bike and after 2 mins same thing happens again. any ideas. thanks in advance beacause i know somebody out there can help me.

 

replace the chain and tensioner before you bend a valve and damage the piston. happened to me. get a heavy duty chain off ebay, there really cheap there. tensioner gona have to come from dealer. thats alot of work to have tried putting the orginal back on. shoulda replaced it from the get go. have you noticed any ticking before this happened?

 

yeah it started ticking like right after i 426 it. like a slight rattle. someone told me they make a lil tick after boring so i thought nothing of it. and with the tensioner it just slides right in no work at all even with the arm all the way out.

 

DO NOT RUN THE ENGINE!!! You will destroy it. I'm shocked you have not already knocked the valve through the piston. The lil' tick they make 90% of the time is either valves needing adjusted or timing chain. As gsjeepxr said get a heavy duty chain and check the tensioner and guides. I had an experience where the timing chain guide was actually broke. Make sure you get the engine rolled to top dead and timing marks lined up properly when putting the chain on.

Good luck with it.