How To Check and Adjust Valves

[Woody_393]

This last weekend I checked my valves on my RMZ450 for the first time (just doing the routine maint.) and decided to take pictures of the process. We are always telling people to check their valves and though it's an easy process, I believe most are a little scared of doing it. I'm doing this in the hope that it will help someone save some money and do this job themselves.

It really isn't very difficult.

Difficulty: 5/10
Time Required: 1 - 2 hours your first time, 30min - 1 hour after you've done it a time or two.
Tools Required: 3/8" Metric Socket Set (preferably 6 sided), Feeler Gages, Set of Hex Wrenches (preferably the socket type), magnet, a Torque wrench, and you manual with your bikes clearances and torque specs. I also HIGHLY recommend getting a hotcams shim kit. Typically 450's need the 9.48mm set and 250F's need the 7.48mm kit -- chasing down shims from dealer to dealer can turn a 2 hour job into a few days in short order if they don't have the shim you need.

My bike is a 2007 RMZ450, dual over heard cam, which is the same as all the other bikes with the exception of the Honda UniCam, which is a single cam design. The Yamaha is the same as my Suzuki as well, but adds an additional valve on the intake side, but all in all they are all the same.

I have adjusted Honda Unicam, Yamaha 250F 5 valve, and now my Suzuki 4 valve dual cam (should be very very similar to the Kawi), and I can tell you it is all the same. Some very minor differences that your manual will help you get around, but otherwise, they are all the same so this should be a good primer to get you started.

Before we begin, make sure you know what your valves clearance is supposed to be. I also suggest getting your bike as clean as you can, since dirt is NOT your friend when working on a bikes engine. Mine is not perfect, but it's clean enough.

typically they are listed in Ranges. My Honda was listed as follows:

Intake: .18mm +-.03mm
Exhaust: .28mm +-.03mm

My Suzuki is:

Intake: .15mm - .20mm
Exhaust: .18mm - .23mm

Yours should be something similar. If you do not know your clearance spec, you can check this thread to see if it's listed: Master List: Motorcycle Valve Clearance Spec

All of these pictures can be seen in full size by going to my photo gallery How To Adjust Valves

Lets get started.

1) Remove your seat (sorry no picture)

2) Unbolt the gas tank and shrouds from your bike. Do not remove the bolts holding the shrouds to the gas tank. That is one additional step you don't need to take. See the red circles to see the bolts removed.



3) Turn off you gas if not already off. Remove the fuel line from the down side of the fuel petcock, and then remove the bolt holding the petcock so it's free. I also try and always put bolts back where they do whenever I can, otherwise, keep track of where they go. You actually don't have many bolts on this job, so keeping track should be easy, but I do put the petcock bolt back where it goes for this one.



4) Remove the gas tank and shrouds and put them off to the side where it won't be kicked over. Also pay special attention when pulling the gas tank off since you will need to help the fuel petcock find its way out.



5) You should now have a partially naked bike, which is where the fun begins.



6) I like to keep track of all of my valve adjustments in a little black book I have that was recently rained on (), so I make notes of the hours, and my valve clearances both before and after adjustment. I absolutely love my hour meter -- if you don't have one, you should get one. It makes maintaining so much easier because you aren't guessing anymore.



7) Remove the spark plug wire and put it off to the side, and then remove the valve cover bolts.





8) Now remove the valve cover. Also, if you valve cover is dirty at all, I would clean it off as well as you can since you do NOT want dirt falling into your motor. I also had to use a rubber mallet to get it to come off since it was stuck on there.



9) Get your bike to TDC by removing the timing and crank covers. Put a socket on the crank and turn it counter-clockwise (the same way your kickstarter turns it) and get it lined up with the TDC (Top Dead Center) marks. You will want to refer to your manual for which mark it is. I believe most all bikes have 2 marks (the Yamaha, Suzuki, and Honda I've done all did). I believe on all that I've done it is the 2nd mark that indicated TDC -- On my suzuki it is the 2nd mark.

Now just a tip to save some time. I never bother putting my valves at TDC unless my valves actually need adjusting. For the initial check I just turn the motor over with the kick starter until both sets of cam lobes are pointing away from each other (just like the above picture), check them, and if they don't need adjustment, I button everything back up and go riding -- otherwise, I make sure it's at TDC before removing anything else. I also like to pay special attention to the alignment marks on the cam sprocket once I'm at TDC so I know what I'm trying to achieve when I put it all back together.



10) Now grab you feeler gages and get to checking your clearance. If you are lucky they will all still be in spec. My Exhaust valves were, my intakes were not.



The gage should slide quite easily between the cam lobe and the bucket (light drag -- not free sliding, but it should drag some). If they do not, use a smaller feeler gage until you can successfully get the gages in there. Be careful if you have to use anything .12mm or less since they bend really easily if you try and force it -- if it will fit, it will fit pretty easily, if it won't, go to the next smaller size.

I like to start with a feeler gages that's within the spec for the valve I'm checking and then go from there to see where the clearance is at.

Intakes: I stated with a .15mm, which did not fit, so I went to a .12mm, which did fit under both. The left side was a nice .12mm, the right side was a pretty tight .12mm, which tells me it's probably .11mm or so.

Exhaust: I started with .18mm and it fit under both valves pretty easily (very light drag), but the next one larger (.21mm) did not, so they were both within the .18mm - .23mm.

A note about feeler gages -- In my experience the craftsman type I'm using here always skip ~.03mm between each feeler gage, so you'll want to keep measuring until you know roughly what the actual clearance is -- this will help you choose shims if you need to make any adjustments.

After I have my clearances, I always write them down with notes about how the gage slide under them, e.g., Tight .12mm or loose .12mm (loose meaning pretty close to a light drag) -- Regardless of whether or not they need adjustment or not.

## If you Valves do NOT need adjusting, you are done with this "How To". Grab your torque wrench and start buttoning everything back up the same way you found it and have a good time riding.

If you need to adjust your valves, keep reading...

11) With the engine at TDC (Get the engine at TDC if you haven't already), it's time to remove the cam chain tensioner. It's typically located on the back left side of the cylinder.

You can remove the center bolt either before or after you take the entire thing out -- just be careful because it might be spring loaded -- my suzuki is, my honda was not. These seem to be quite different from bike to bike, so refer to your manual for the proper way of removing it and re-installing it.





12) Once the cam chain tensioner is removed, it's time to take off the camshaft journal holder. Now since I'm not going to mess with the exhaust valves/cam, I took a zip tie and tied the chain to the sprocket so the chain wouldn't jump off, which will help when putting everything back together -- keeps it in time. Also, if I was going to adjust both intake and exhaust, I would do them in steps, e.g., do the intake, put it back together, zip tie the cam chain to the intake sprocket and then start on the exhaust...



Now take the proper sized socket and start removing the bolts. Your manual will tell you which order to loosen the bolts -- this IS important. If you don't follow these instructions, you can warp your camshaft journal holder, which turns your cheap maintenance job into a couple hundred dollar job. My brother actually did this and sure enough his warped and it cost a couple hundred $$$ to get it fixed.

I like to start with the first bolt and loosen it 1/8 of a turn, then move to bolt number 2, and do the same thing until all bolts are 1/8 of a turn loose. Then start over, this time going 1/4 turn for each until they are all done, then simply remove all the bolts in any order you want once they are loose -- Coincidentally, installation is the same. Tighten them up finger tight, then 1/4 turns on each in an order that your manual should specify until everything is snugged up (with a torque wrench of course).

Once the bolts are un-threaded, remove the camshaft journal holder -- they typically have 2 dowel pins that you will want to make sure come out with it or stay put -- either way is fine, just make sure they don't fall into the engine (down the area where the cam chain goes... ). The dowel pins also make the removal of the camshaft journal holder a little tough. I used a CLEAN rubber mallet to tap on the side of it to get it moving, then I simply pulled up on it with my hands to get it the rest of the way off. Again, make sure those dowel pins are accounted for, and PLEASE don't use a screwdriver to pry up on the camshaft journal holder. Chances are pretty good you'll do some damage to the exterior cover -- I suppose if you put a block of wood as the fulcrum and a clean towel under the camshaft journal holder you should be fine, but this stuff is all Aluminum, so it bends and galls easily so be careful.



13) Now remove the intake camshaft (or exhaust if that is what you are working on).

Getting a bike in time is one of my least favorite activities when it comes to working on bikes, so I try my hardest to make the job as easy on myself as possible. In this case, I was able to leave the cam chain in its place and simply roll the cam up on top of the other cam so it was out of the way -- ensuring not to jump a tooth etc. Now that I've done this once, next time I will put a zip tie on the top (between 10 -12 o'clock) of the cam I'm removing so the chances of it losing time are NILL as it will still roll with the zip tie there. My honda was not this easy...



**Reached my 20 images max, so onto next post**

[Woody_393]

Continued...

14) You can now see the tops of the valves buckets. One at a time (meaning do one completely before moving onto the next one) remove the bucket from the top of the valve. Sometimes (usually never) you can get it out with your fingers, but I've found that they are too slick and you can't get a good hold on it, so I use a magnet to help me get the shim and bucket off the top of the valve, which is a lot easier.

Now pay special attention when removing the bucket and shim because sometimes the shim will stay on top of the valve, other times, it will stick to the inside of the bucket (I find using a strong magnet helps the shim stay in the bucket). You DO NOT want that shim to fall into the motor. So again, make sure you know where it is when removing it. Is soon as I have it off enough to put my hand under it, I put it there so I can remove the bucket and not have the shim fall into the motor -- trust me, you don't want to spend an hour fishing for shims

the #1 in the picture is the top of the bucket, #2 is the shim with the bucket removed.



These are pictures of the bucket for those that have never seen one. This first one has the shim still stuck (with oil) to the inside or underside of the bucket. You can also see my notes about this valve adjustment. You might not be able to read it, but it's all there (well most of it anyway since I wasn't done yet).



This one is with the shim removed.




15) With the shim in hand you should (hopefully) be able to read the size of the installed shim. If you can't you'll need a micrometer to figure out what the size is so you can adjust accordingly.

Both of my shims still had the numbers of them, so I was able to quickly change to the correct shim size and re-install.

A little about shims. The numbers on them stand for their measurement in mm. If your shim says 235, that means the shim is 2.35mm thick.

If the process of figuring out what shim is somewhat confusing (it was for me for the first 5 times I did this), you can download a handy little spread sheet that will make this a lot easier. You can get it here --> 4-stroke Valve Shim Calculator (Excel) otherwise, the math is actually pretty simple.

If you need more clearance because your measurement was below the desired (as per your manual) clearance, you need a smaller shim to increase the clearance. Smaller shim, gives more room, which means more clearance.

If you need less clearance, you need a bigger shim.

Shims typically come in .05mm increments, although, they do come in .025mm increments as well, I've never seen where I could buy them in that size. So I end up having to adjust in .05mm increments.

In the off chance that you have a 238 (like I did) that number actually means 2.375mm. Or if you have a 233, that means 2.325mm.

Ok, since my intake clearance on the right side was a tight .12mm (more than likely .11mm) and I pulled out a 238 (2.375mm) shim, what is the correct shim size I need to get my valve clearance back to between .15mm & .20mm?

If you said 230 you would be correct. I could have gone with a 235, but that would put me at the tight end of the spec, and since my ability (tools) to accurately measure is somewhat suspect, I decided to go to a 230, which should put me at around .18mm or so. Checking the spec when I'm done will let me know if I'm right or not.

Now take the new shim dip it in some oil (just to get it lubed) and install it onto the top of the valve with the numbers facing the valve (not up). If you install the shim with the numbers facing you, chances are pretty good the numbers will wear off. If you face them toward the valve, chances are pretty good the numbers will still be there next time you get to adjust your valves.

Install the bucket and move onto the next valve.

The left intake was also at .12mm, but it was a loose .12mm and I pulled out a 235 (2.35mm) shim, with some quick math (.12mm + .05mm = .17mm) I knew a 230 shim would be perfect.

Again, dip the shim in some oil, and then install it on top of the valve with the numbers facing down and reinstall the bucket.

Dip your finger again in oil and put some oil on top of the bucket.

16) Put the cam back in place, making sure your timing is still correct -- which with this new method I used this time, everything lined right up. Re-install the camshaft journal holder (again, keep track of those dowel pins). Tighten to the correct torque (mine was only 10Nm) in the same order you removed them in (criss-cross pattern).

I like to get them finger tight, then tighten in 1/4 turn increments moving from one bolt to the next until my torque wrench clicks at me, then go over them one more time just to make sure (be careful though because you can over torque them if you aren't paying attention).

Re-check your timing marks and ensure they all line up still.

17) With your hand turn the bike over a few times. What this does is it allows the cams to pressurize the shims and remove any oil or air that might be stuck under/between the bucket/shim/valve stem. That way you ensure you will get a better/more accurate reading when you check the valves.

18) Break out the feeler gage and check the clearance again (make sure you are at TDC or at least that cam lobes are pointing away from each other) -- Hopefully you are right where you need to be. I was

My Right intake now measured about .18mm (it would take a .17mm loosly, but would not take my .20mm) The left took the .17mm perfectly Woohoo, I'm now in spec...

Again, triple check your timing marks and if good, button everything back up ensuring to adhere to the torque specs.

Start it up and hopefully it runs

A few words of encouragement. Their were occasions (with my honda) that I had to shim and re-shim 5 times or more because I would choose the wrong shim size, or go the wrong direction on choosing the shim but with time and patience, you can get really good at this, and it will be a snap.

I also like to schedule my valve check/adjustments at the same time I'm going to change the oil and filter. Once I'm done with the valves, I start the bike, let it warm up, stop it, and then change the oil to ensure that all the dust and crap that was left in the motor from the valve adjustment don't get to spend much time in there.

BTW, I rode my bike the next day and I had new found mid-range power that was absolutely awesome . The bike also started easier (not that it was hard before though, it's just a lot easier now).

Feel free to ask any questions you want and I'll try my best to answer.

I hope this is helpful, and sorry I'm so long winded.

[Aus_Rider_22]

Awesome thread! Definitely knowledge base worthy!

I am sure others will use this thread for guidance and understanding when they do their valves!

Nice work mate!

[DRGSin393]

WOW!! The myster is no longer. Kudos for taking the time to do this, it was VERY helpful. Heck, midway through it I though to myself, "I can do this". Then I snapped back into reality. Great job Woodward. Beautifully exposed photos to boot! lol

[MXtras]

Excellent write-up, Woody!

I appreciate all the time this took to compile and write up - as I am sure a lot of folks do and will!

Good stuff, woody.

Scott

[Mainjet2001]

Excellent job Woodward, very good. Thank you....

Is the Honda your next article..... O.K. you don't have to answer.

[Woody_393]

Ha ha, main, that's funny. I might still have some pictures of the honda topend as I have been meaning to create this how to for a long time. I just knew it would be time consuming which it was. I do have pictures of a showa fork rebuild that I have also been meaning to do also.

Anyway, thanks for all of your nice comments. I really do hope this is helpful to someone.

Also, writing this took me a lot longer than actually adjusting my valves did.

[Woody_393]

I did a search with google to see what other "How To's" exist and CRF's only has done one for the CRF250 (which is a bit different). I thought I'd link to it since they did a very nice job.

CRF's Only - How to check and adjust your valves on a Honda CRF250X

[Mainjet2001]

Again Woodward, excellent....

[Flash393]

Awesome write up Woody!!

Thank You this dose help since it's time for me to do the same maintenance on my yamie and I have never done this before.

Yes the virgin voyage in to the valve train for me...

[Woody_393]

Woo hoo, you'll do great. IMOP, the fact that you're willing to try is half the battle. The rest if pretty easy.

Just let me know if you have any questions. I've never done a Yamaha 450, but I've done more than a few Yamaha 250f's which should be similar.

Just know that getting at the middle intake valve, to check the clearance, is nearly impossible without some really thin gages (thin as in wide thin) -- though it might be easier on the 450.

[Woody_393]

Update to assist the Honda guys since the Unicam is a bit different.

Here are a few pictures showing the Honda Unicam topend (yes these are from my 2003 CRF450).

The key things I'm showing here is how I secured my cam chain and sprocket.



I had completely forgotten what the Unicam looked like until I went through some of my old pictures looking for some examples and found this.

This is the unicam removed from the head. You can see on the left the bolts that normally hold the cam sprocket to the cam. You will have to remove the cam sprocket first before tying anything up.

First remove the bolt that you can't get to when the bike is in time. The remove the second bold after you get the bike in time. Then zip tie it together (I tied it up so it wouldn't fall down as well).



Anyway, hope these help.

[zrealdeal]

Hey Woody, On your CRF how did you remove your cam chain tensioner? Did you use the special tool the service manual calls out? Do you have any pictures?

[Woody_393]

I do not have a picture, sorry. However, I just used a small screw driver and it worked just fine.

[zrealdeal]

you mean you used the screwdriver to hold the tensioner in place when you took it out. or you used a screwdriver to remove the unit?

Sorry for the dumb questions. I've just never messed with the cam chain tensioner.

[Woody_393]

I used a screwdriver to remove the tension.

I actually remove the tensioner by the two bolts on the side.

I had a little tool that came with my new cam chain tensioner that would hold the tensioner so it didn't have any tension until I could get it re-installed... Then I just pulled the little piece of metal out of the hole and it released the tension.

[surgersandman]

is he ttr 125 the same way

[Woody_393]

The TTR should be very similar (the concept is the same), but actual adjustment should be a lot easier. I'm pretty sure you will have a screw and lock nut to adjust yours with.

[HEMIwes]

When it comes to the cam chain tensioner on my 05 CRF450, I use a small screw driver to release the tension and then I put a small vice grip on the screwdriver to hold it in place. It'll stay there and you don't have to take the cam tensioner all the way off. nice little trick.

[Woody_393]

Great trick HEMIwes and thank you for sharing it!