400ex knockin or sumthin

[cannondale4life]

just got a 2005 400ex about a month ago and the things knockin already im not sure what it is though or if 400s are known for problems like this if anybody knows anything about a pretty noisy motor and has some advise to give i would well appreciate it

[rob_990]

is it all stock? maybe the valves need to be adjusted.

[cannondale4life]

yes the quad s completely except the baffles out,i think it sounds like a knock more than a hard tap,also its starts right up with no problem if that helps.

[01trx400]

put the baffle back in. that motor wont last long unless you jet it for that.

[rideracelivemx7]

4 strokes deveop a knock. iuts usually thre connecting rod bearing. tear off the top end and wiggle the rod back and forth. youl see what im talking about. being healthy would be about 16th of an inch of play back and forth. it won't do anything really. unless your an *** and beat the hell out of it, then you can spin a bearing and by by bottom end. my yz250 needs a new bearing. aslong as you don't beat on it, then your fine for a year or so.

[cannondale4life]

well when it happened i was hittin a new 35ft double i built when it happened and to clear it i had to be 2nd gear pinned if i put it in 3rd i would just lose power im hoping this isnt the cause of all this