adj. valves on 400

1 reply to this topic
  • rmx250rider

Posted November 03, 2009 - 05:31 PM


need your help grayracer!

98 yz400F the manual from the yamaha wesite doesnt really explain to me well

What are the specs for it

how do you check them?

and i know you have to take out the cams, but how do you get it timed right again?

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  • grayracer513

Posted November 03, 2009 - 07:18 PM


The specs are on page 3-18.

The checking procedure is also on that page, but the '98 manual uses photos instead of drawings, which don't show up very well in second and third generation reproductions. To help with that, download a manual for a 2000 model YZ426, and use the procedure on 3-19. Just be sure to use the specs for the 400.

You only have to remove the cams if an adjustment is necessary.

Proper instructions for removing and reassembling them is on 4-19 of the 426 manual, or 4-23 of the 400 book.

Pay particular attention to the process and specs for torquing the cam caps back down. Always set the caps by hand, NEVER draw them down with the bolts.

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