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Discussion Starter · #1 ·
I know this is a raptor forum but most quads are pretty close to the same thing in basic sense so I have a question on my 2002 400ex. Its making a ticking or clinking noise in the top end. It just recently started. Its random and not really in any pattern. It sounds as if I were taking a screw driver and lightly tapping it against the exhaust or something. Its definatly internal and I checked all bolts and nothings is loose. Sometimes even after it makes a tink the engine will shut off. Any suggestions or places to start? Ive never taken apart a top end so I didnt wanna do it till I knew what it could be or where I should start. Thanks guys. :thumbsup:

-Eric
 

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i had the same noise on my blaster and it come to be that the piston was slaping and high rpm's . so i found it after it blew up at the dunes while it was stuck in a rut. :unsure:
 

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Discussion Starter · #3 ·
Oh great :eek:

Since I caught it early maybe I can still save it. Any one else have any experiance on this? Are pistons hard to replaced by an medium experianced person like me or are they best left to the pro's?


One thing is your blaster is a two stroke where as mine is a four stroke so thats a big difference and mine does it at idle.
 

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It might be your timing chain is lose. you said it was not consistant.... Take off your head and find out. That will be the easiest way to solve your problem. The piston isn't hard to replace. It's just like a car piston, but instead of sliding the piston into the cylinder, you slide the cylinder onto the piston and rod assembly.
 

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Discussion Starter · #5 ·
If I take the head off am I gonna need to replace any gaskets or anything? I dont know how to adjust the timing chain so is that very difficult?
 

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You don't have to take the head off to check the timing chain, just the valve cover. It' uses yamabond type gasket sealer, so just pick up a tube if you don't have one.
 

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you can't adjust your timing chain. It has a tensioner on the chain, but as you know chains were out and the tensioner no longer keeps the chain tight. Look at it and see if it's within specs. If it isn't, you'll just need to replace the chain.
 

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Discussion Starter · #8 ·
Cool, thanks guys. Ill look at that and go from there. If it is the timing chain and its worn out and needs replacement is it very difficult to do?
 

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difficult no...time consumming yes. You'll need a flywheel puller...what your going to need to do is take off the side case with the stator...**starter and what not****pull the flywheel and oneway assembly off. and install new chain
 
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