Anybody done the valves on an 04WR450.

5 replies to this topic
  • Atlasrider

Posted December 09, 2004 - 04:56 PM


I am getting a lot of different thoughts on when to do the first adjustment and what exactly should be done. According to the manual after the break in period they should be adjusted every 500k. The service mgr. at one dealership told me that he was seeing the valves tighten up on new bikes. This makes them hard to start when hot. I did the break in period with the throttle stop in, then removed it and cut it down to size to allow full throttle. Other than that I am on the 3rd oil change and the bike still runs good. However on the last ride I think I was hearing a tapping in the valves at high speed on a long straight dirt road. The manual is very detailed about how to remove the valves and valve springs checking them with surface gauges etc.
Since I don't have valve spring clamps or a surface gauge I guess I'm SoL
If you've done yours what did you see, did they require adjustment. How often do they need to be done. Do you need any special tools. How hard is it
Can anyone list a step by step procedure for those of us that have never done valves on the new generation 4 stroke. :cry:

  • Indy_WR450

Posted December 09, 2004 - 05:12 PM


If you are not racing the engine and just trail ride the WR450 check the valves at 1000 mile intervals. The intakes will tighten up first. If you dont reve the engine much you can go 3000 miles between adjustments. If you ride a lot of sand and rev the bike out before each shift you will need to adjust the valves every 1000 miles for sure. :cry:

No special tools are required except long skinny feeler guages.
Buy the hot cams shim kit for $60. that has all the necessary shims for changing clearences. Instructions are easy to follow from the manual. :cry:

Note watch out for the bearing half ring circlips that locate the camshaft bearings! They like to lift up with the cam and fall off into the engine. :cry:

  • Atlasrider

Posted December 09, 2004 - 07:19 PM


Thanks Indy,
After rereading the manual again I did find the section (3-19 - 3-24) that explains the clearence adjustment process. Where did you get the hot cam kit? HAve you had to make many adjustments to yours. Where I ride there is a mix of stuff. I do like to ride fast and occasionally I end up in the sand. So I would have to say that my engine is reving at race speeds about 70% of the time. Doing big climbs or in the sand, or on long straight-aways.

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  • Indy_WR450

Posted December 09, 2004 - 07:22 PM


I got the hot cams kit for Zip Ty racing:


  • postalrider

Posted December 09, 2004 - 07:23 PM


i just checked mine again at 3000 miles and they were perfect!my advice is to remove your tank and roll it in to your local dealer it will only take a few minutes for them to check the clearances.peace of mind is worth more than a few bucks

  • toyota_mdt_tech

Posted December 09, 2004 - 07:42 PM


OK, new valves are ground at slightly different angles, ie 45' and 46', this means a small area of the valve/seat surface contact each other. This is done for better sealing. But this will allow the valves to seat in as the difference in angles become the same angle. This allows the valve to "sink" into the head thus increasing the valve stem length which reduces clearance. Once these are seated, valve clearances will remain constant for a lot longer (after 1000 miles) and if you start to hear excessive clearances, look for abnormal wear. Rule of thumb, they will usually get tighter with normal wear. These use the "shim under bucket" design, so compresing the valve to remove the shim wont work. You must remove the camshaft then the follower to get to the shim. Most engines with aggressive lift cant use the "easy to adjust" "shim over bucket" as the cam will spit the shims out at higher RPMs. Like one member said, checking adjustment is easy, and easy for anyone with some feeler blades to do. Check it, if it needs it, run it to the dealer or get the stuff and tackle it if you feel you can do it. If your lucky, clearances may be within specs which is usually a range ie .004-.009 etc.


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