newbi with 98yz400

3 replies to this topic
  • halftimer

Posted February 25, 2006 - 03:39 AM


this is my first 4stroke bike. I traded a 95 yz 125 and $400 for it. its in pretty good shape, a bear to start, it has apd tripple clamp, answer fat bars, some sort of front brake caliper aftermarket, stainless brake lines, and I think someone has been in the motor not sure though but there is locktight outside the edge of the cam tensioner. what should I look out for or should be my first mod on this bike? it seems to have less low end grunt than I expected. the pipe leaks at the mid pipe connecter around the kickstarter, no big deal plan to fix that as soon as it is warm enough to ride it. any pointers at all would be appreciated.

  • mxerhale

Posted February 25, 2006 - 09:49 AM


You didn't really ask much of a question but, if it's it hard to start I'd check those valve clearances ASAP. If it suffers a lack of low end and it's hard to start you may even do a compression check (check the valves first) to make sure the top end isn't worn out.

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  • halftimer

Posted February 25, 2006 - 12:12 PM


are the valves tappet or shim? and will the 450 cam mod work on mine. I found a link searching on here to a site that gave detailed instructions but the oldest in reference is like 2000? I also wanted to know if there were any typical probs to watch out for. thanks

  • jbrooks26

Posted February 25, 2006 - 02:49 PM


The valves are shimmed. The 450 mod will work on yours, you want 14 pins between the two upper timing marks on the intake and exhaust cams. This is with the engine at TDC of the compression stroke of course. Hope this helps.


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