400ex jumping time

[shelb963]

Hello
I have a 400ex that always jumps time. I have put a new tensioner and timing chain old one was stretched but still will not stay in time. All the gears and timing key appears to be fine
Has anyone ever ran into this issue before? :ermm:

[REDRIDDER]

I'm not questioning your mechanical skills but what makes you think it jumps timing? Is it that noticeable that it wont run or runs rough.Give me the symptoms of the problem you having...How often does it do this all the time when your jumping or any time?

[shelb963]

well I align the T on the flywheel and the 2 marks on cam sprocket parallel to the head (with the last mark on top). put it all back together rides good for a few minutes till it is ran hard and starts rattleing and running poorly. I align the T back up pull the rocker box and marks are not aligned anymore. I have been fiting this issue for months. First the tensioner was faulty ordered a new one. installed same problem again aligned back up 2 more times same problem align the T back up pull the rocker box and marks are not aligned anymore.
Then I read that the cam chain are bad about streching. Behold another hard run chain came off this time so I ordered a new one heavy duty. I thought this was the end of my issues put new chain on and aligned marks and ran good for a few minutes and now it is making a loud ticking and rattleing noise again. If I was a betting man I would bet that the timing marks are not aligned again.
could be the rev box cdi allowing it to turn to many rpms and will not take the abuse didnt do it before turning so many rpms

[REDRIDDER]

I will research your problem and come up with a solution for you, your crank is true?

[ncsmash]

did you also align the TDC mark on the flywheel when you aligned the cam sprocket marks???

[RiderTRX400ex]

are your cam chain guides, the black plastic sliders, in place and seated securely? i would rule out the cam chain and tensioner as your problem, and take a closer look at the chain guides, and the teeth on both the sprockets.

GL

[shelb963]

10 - 4 thanks for the information I will check into this soon thanks

[shelb963]

Originally posted by REDRIDDER
I will research your problem and come up with a solution for you, your crank is true?
yes the crank is true