Adjusting The Valves.

[Duane]

This is a basic tutorial on how to adjust the valves on the YFZ.

Step 1: Remove front plastics and gas tank.

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Step 2: Remove ignition coil, oil tank breather hose and cylinder head breather hose.

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Step 3: Blow out cylinder with compressed air to remove water and/or dirt around the spark plug. Then remove the spark plug. Remove the valve cover.

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Step 4: Remove timing mark and crankshaft access screws.

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Step 5: Turn crankshaft counterclockwise until the "I" mark lines up with the AC magneto rotor. Verify you're at TDC by making sure the punch marks on the intake and exhaust cams line up with the cylinder head. (This is the stock YFZ timing. Rotate the exhaust cam one tooth clockwise to do the "cam-mod". There are 14 pins between the top two punches and when the cam-mod is done there should be 13 pins between them.)

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Step 6: Measure the valve clearance with a thickness guage. If the valve clearance is out of spec record the measured reading.

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Step 7: Loosen tensioner cap bolt and remove the timing chain tensioner. This is an optional step because you can release the tension while it's still installed and have enough slack in the timing chain to do what's needed.

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Step 8: Remove camshaft cap bolts in a crisscross pattern in stages working from the outside inward.

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Step 9: Stuff a rag around all the openings in the motor so nothing falls in like the circlips. Secure timing chain to the frame using a wire-tie then remove the camshaft cap and camshaft.

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Step 10: Remove the buckets along with the shims using a maganet.

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Make sure you keep everything in order and take notes of what bucket had what shim in it and what valve it went to.

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Step 11: Replace shims using the conversion chart provided with the service manual.



Reassemble everything according to the service manual using the proper torque measurements with engine assembly lube or a heavy weight motor oil.


Hope this helps a few people out. And if I missed anything please let me know.

This is a basic outline of how to adjust the valves on the YFZ. ALWAYS refer to your service manual for more detailed instructions because I didn't cover everything in the tutorial.

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[YFZ450 #69]

the sticky bandit has struck again

good work Duane, once again!!!

we need a "pat on the back" smilie



just one thing to make it a bit easier, its not a necessity to remove the ACCT, you an just "unload" the preload on it, and there is enough slack in the cam chain to do the job. I find its alot quicker when you dont have to stuff around removing the 2 bolts that hold it in as there isnt much room to work there

GOOD WORK

[Duane]

A select few edits and relocation of the pics. Thanks for the suggestion.

[Toadz450]

It says the photos have been moved or deleted. Can you put the pictures back up?

[Duane]

I'm starting to hate photobucket.....nothing but problems lately. Sorry for the delay.

[Earnhard3]

duane- did you upload them like I told you in a pm?

[Duane]

I know how to do it but I just have to make time.....which it seems I have alot of but some things have to be first and some things have to be last.

[Toadz450]

They're up now. Looking good. I gave a friend of mine this link and I just thought I'd take a look over it again and I noticed the pictures weren't working. Wanted to make sure the guy got to see all the pics to go with it. Thanks for fixing it.

[Duane]

Can everybody see these pics in the first post? I've gotten a few PM's saying peeps can't see them.

[Earnhard3]

I see them

[blackwell17]

I see them....THANKS!!!!

[pondy]

somthing ive been thinking about, can you check the valves with the came more, or do you need to put it back to stock timing before you check them

[Duane]

Same clearances as stock timing or YZ timing (cam mod).

[svtbolt04]

What size allen head do I need to take off the crankshaft cover..My number 10 isnt big enough. Then what size to spin it?

[Mud Rooster]

oh boy, this is alot different than the honda setup

sou you can only use shims, eh?

[kccaroYFZ450]

What is the "cam mod" that you were talking about? If I'm running a stock exhaust and header-actually, everything on my motor is stock except my K&N air filter, stock jetting even-would it be worth my time to put in high performance cams? What can I do to my existing cams to enhance my machine's performance(if anything?) If I do decide to look into doing a cam mod, which cams and from where should I put in? Should I even worry about doing ANY kind of cam modifications if I'm still running a stock exhaust? I'm working with a limited budget, and would like to know where to start on this pretty much bone stock machine. Thanks!!!

[jdthomas24]

What is the "cam mod" that you were talking about? If I'm running a stock exhaust and header-actually, everything on my motor is stock except my K&N air filter, stock jetting even-would it be worth my time to put in high performance cams? What can I do to my existing cams to enhance my machine's performance(if anything?) If I do decide to look into doing a cam mod, which cams and from where should I put in? Should I even worry about doing ANY kind of cam modifications if I'm still running a stock exhaust? I'm working with a limited budget, and would like to know where to start on this pretty much bone stock machine. Thanks!!!
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[jdthomas24]

The cam mod is that the timing from factory is advanced causing the detination to be a tad early. you can relieve this by retarding the timing by one tooth or rejetting to run a higher octane gas. i havent heard of anyone one using higher octane but everyone does tghe cam mod. i am actually doing the cam mod and adjusting the valves this wekend and i will let you know the difference it makes.

What is the "cam mod" that you were talking about? If I'm running a stock exhaust and header-actually, everything on my motor is stock except my K&N air filter, stock jetting even-would it be worth my time to put in high performance cams? What can I do to my existing cams to enhance my machine's performance(if anything?) If I do decide to look into doing a cam mod, which cams and from where should I put in? Should I even worry about doing ANY kind of cam modifications if I'm still running a stock exhaust? I'm working with a limited budget, and would like to know where to start on this pretty much bone stock machine. Thanks!!!
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[jbplays]

Good post!

[jdthomas24]

Alright, i did the cam mod and completely forgot to post the results. It was a bit of a headache to adjust the vavles and such but while your doing the vavle adjustment ( which should be once a year fo casual riders and twice a year or more for racers) you should just do the cam mod while you are there. one thing,,,,,,,,,,,,,,,,, take the spacers between your carb boot clamps out, they cause me am incredible pain because under a laod it was still sucking air. i wen throug complete h@ll because of that with jetting, timing check and all of that , took me a weeek or so to find it and fix it. now my jetting is so screwed up i am still trying to fix that.