my engine makes a clacking sound what could it be

 

time chain loose and/or time chain guide broke.

 

I just had the same thing happen in my 450r. I opened the top end and found the timing chain VERY slack, pulled the tensioner out and it was stuck in. Would not go back out. I got lucky b/c it jumped timing a little and I didn't have a valve and piston meet and hit.

 

so u guys are pretty positive its the timing chain?

 

Well, not positive but, they are known for the stock timing chain becoming loose. Symptoms are you'll here a small ticking that usually gets louder over time. Also, it don't typically get louder as the engine is revved.

Get a heavy duty one and replace it. While your in there check the guides and make sure that they are not broke. One of them broke on my bro's 400 causing more noise.

 

right on thanks for the help im gonna tear into soon and have a look