07' wr450 valve adj. tips and tricks?

Hi all,

Well, I'm going to check the valves for the first time this weekend:eek: . I have read the manual and many posts about it, but I'm still nervous about it. I don't think I will have a problem checking the gap, but if I have to make an adjustment I will be a nervous wreck until it all goes back together and it runs! Anyone have any tips, tricks, do's and especially DON'T do's? Thanks in advance for your input.

It's really quite easy.

1. Set the engine to TDC. Check the timing marks at the top engine plug.

2. Clean everything real well and remove the tank.

3. Clean everything again and remove the top engine mounts and valve cover. Double check the timing marks on the cam gears to see that you're at TDC.

4. Measure the clearance at each valve and record the info. The largest feeler you can fit is the clearance, i.e. I could get the .09mm feeler in, but not the .10mm feeler, so the clearance is .09mm.

5. Check to see if you're in spec. If not, subtract your measured clearance from the spec'd clearance. This is how much you need to REMOVE from the respective shims to get back in spec, i.e. I had a 189 shim, round that to 190, needed .05mm to get back in spec, so I used a 185.

6. So as to be sure the cam chain does not skip a tooth and loose time, I removed one cam at a time and tie-wrapped the chain to the other cam. Remove the cam chain tensioner and remove the cam. Be careful with the half moon clips under the gear side cam caps.

7. Now remove one bucket at a time and check the shim size. I used a magnet to get the buckets and shims out. Record the info and make sure the buckets go back on the valves they came from.

8. Install the new shims and repeat for the other cam.

9. Put everything back together and re-measure. You'll need to remove the center bolt on the tensioner and turn the small screw inside clockwise to get the tensioner back on.

10. Turn the engine by hand a few revs to see if everything looks good and nothing is binding.

Well, I could't wait to tear it down. I checked the valves last night and all of them are in spec but just barely. Intake is @ .010 and exhaust is @ .020, which is at the min. spec. Should I re-shim to put them in the middle of the spec, or leave them alone and ride?

Personally, I would re-shim because they're just going to get tighter, but it kinda depends on what shims are in there.

The factory uses shims in .01mm increments, but OEM Yamaha shims (what you can get from the dealer) come in .05mm increments. If, lets say, you have a 189 shim (1.89 mm) and you switched to a 185 shim (1.85mm), you just added .04mm to your clearance, bringing you within tolerance without being at the edge. Now, if you had a 191 shim, a 185 would add .06mm to your clearance, taking you out of tolerance. What you could do in this case is use OEM Honda shims which come in .025mm increments. A 188 (actually 1.875mm) would add .035mm to your clearance, leaving you in spec.

Pretty much all big bore bikes use the same 9.48mm OD shims, so it's not a problem. I actually ordered Honda shims for this exact reason.

Personally, I would re-shim because they're just going to get tighter, but it kinda depends on what shims are in there.

The factory uses shims in .01mm increments, but OEM Yamaha shims (what you can get from the dealer) come in .05mm increments. If, lets say, you have a 189 shim (1.89 mm) and you switched to a 185 shim (1.85mm), you just added .04mm to your clearance, bringing you within tolerance without being at the edge. Now, if you had a 191 shim, a 185 would add .06mm to your clearance, taking you out of tolerance. What you could do in this case is use OEM Honda shims which come in .025mm increments. A 188 (actually 1.875mm) would add .035mm to your clearance, leaving you in spec.

Pretty much all big bore bikes use the same 9.48mm OD shims, so it's not a problem. I actually ordered Honda shims for this exact reason.

Can I ask where you ordered your Honda shims from?

I have decided to just put it back together without re-shimming (I will check them again in about 6mo. if they move then re-shim). Now I can't seem to get the cam cover back on:foul: :ride::banghead: . It barely came out of the frame. I have now taken more stuff off the bike to create more room but the wires and hoses get in the way of the angled vent fitting on top of the cover. Does the fitting come off? Any ideas? :busted:

Just keep at it and it will go back in. Pay special attention to the cables and wires above the cover. Push those out of the way aggressively. Its like a Tetris game. I have checked mine twice and both times it was a zen game of patience to get the cover back on.

The motorcycle Zen gods were with me this afternoon! The bike is back together...and it runs! I'm sure next time won't be such a dramatic event. Thanks for your input and words of encouragement.

How many miles / hours do you have on the bike?

I don't have an hour meter yet, but I would guess that I have 30-40 hrs on it. This was the first time the valves have been checked. I am hoping they stay right there for a long time. Like stated above, I will check them again in about 6mo and see if they are moving.

Hi all,

Well, I'm going to check the valves for the first time this weekend:eek: . I have read the manual and many posts about it, but I'm still nervous about it. I don't think I will have a problem checking the gap, but if I have to make an adjustment I will be a nervous wreck until it all goes back together and it runs! Anyone have any tips, tricks, do's and especially DON'T do's? Thanks in advance for your input.

Set all valve clearance biggest in the adjustable area.:busted:

It is the theory of 4stroke racing motor. :banghead:

I have an 07 WR450 with 600 miles on it. I checked the valves last week and the intakes were right on the lower limit. One exhaust was on the lower limit and the other was .19mm (just under the limit). Is this normal? My buddies who ride CRF450s have a hot cams shim kit out at the desert where the bike is stored. Will these shims work?

Thanks in advance

Maynard

WR450 07

Ill be ready to check mine for the first time this spring, A bit nervous but willing to do it. I was thinking about buying a shim kit before i even start. I seen kits on ebay, IS that a good idea?

thanks

The motorcycle Zen gods were with me this afternoon! The bike is back together...and it runs! I'm sure next time won't be such a dramatic event. Thanks for your input and words of encouragement.

Good deal. I have been running tight for a while now. I think .15mm In and .04mm Ex. Have not had any trouble due to this and all is fine. Guess if I was WOT all the time I might consider changin this out but as long as I have some clearance I am Ok with mine. If I were way loose I might tighten her up but is Kosher for now. If there is an someone that can talk me out of runnin tight then I will listen to what they have to say but till then I aint doin nothin but rollin back the gas.:smirk:

A SUPER helpful tip to get the valve cover off without a hassle, is to remove the lower front engine mount bolt and nut, then loosen the very bottom engine mount bolt and tilt the front of the motor down about a 1/4 inch. this give a little more room making it way easier to get the valve cover off without worry of damage to the cams.

Thanks for the tip - I check mine a few months ago and spent an hour trying to get the cam cover back on. 

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