installing 03 cam in 99 yzf

ok ive got everything torna apart and ive got the cam ready to go. how do you know whcih is the right position for the ex cam. theres 2 punch marks on it but not really in the same place as on the old cam. which mark should i got by? and after the installation should i check the valve clearances or should that be done after its been riden for the first time.



Click the link in my signature and all will be revealed... you cannot use the punch marks on the 03 can to line it up... and you need to check your shims/valve clearances before you start the engine...


With the new cam installed, you want the intake and exhaust cam lobes to be in the same position as they would be with the old cam in place. When the new cam is in place and timed corectly, you should have 14 timing chain pins between the dots on the intake and exhaust cams and the intake and exhaust lobes should be facing away from each other.

The cam PDF has good pictures of what this looks like and a good description of the procedure.

Here is a link to the PDF. (right click and "save as") PDF Link

As far as the valve clearance go, you will first need to install the new cam with your old exhaust shims in place. Then check your clearances (before riding or starting) and determine what size shims you will need to bring the clearance into spec. Once you have determined what shims you will need, remove the new cam and replace the old shims with what ever size shims you determined you need. Re-install the new cam and you should be good to go.

Hope this helps. Good luck!

Listen to Yamadude and get the PDF in front of you when doing this. Also make sure you are on TDC in the power stroke. One tooth off can make the night and day difference in how it starts. The back side of the cams should look as they are laying down pointed away from each other. The more pointed up the more dangerous it is to run the motor. Run the bike through the stroke before you lock her down. AT least 3 times to feel the compression and check cam movement. If you fallow the PDF correctly and get it right the 1st time you won't become an expert on getting that damn retainer ring and cam cover in place. Good Luck ...Enjoy the new no hassel start drill! :thumbsup:

the PDF is THE ONLY way to go. Here are some additional pics to back that up!

Satch's 450 cam install pics

i noticed on the one pic that you didn't have to remove the intake cam. even if i take the tensioner right off both cams still have to be removed just to remove the ex cam.

[@#$%&*!], my computer is a piece and those pdf links won't work at all.

just remove the exhaust cam.

[@#$%&*!], my computer is a piece and those PDF links won't work at all.

If you can';t right click and "save target as..." on the link in my signature, then you must have a firewall or something in place that stops you downloading it. If you can download it, but just can't read it, then you need to upgrade acrobat on your computer... The PDF file should work with Acrobat 4.0 and above...

If all else fails, then PM me your e-mail address and I will send it over to you...

Good luck,


Ok here ya go. Right click on these images and save them. Print them out and take them out to the bike with you. Also below these images I have reposted one of my threads that includes how to check and adjust your valves. Using both the PDF/450 Cam mod images and the valve instructions will get you there I promise!!



Anyone interested in doing the cam swap here are my recomendations. Use the 450 Cam mod instructions here in this post along with Garrett's instructions on how to adjust the valves on a YZF (pasted here inthe post also). Garrett's instructions will give you what you need to know if you have never had the cams out of your bike. It will help you on how to measure the valve clearances so you can get the proper shims. You may need larger shims. Some have reported that they did not have to change them while alot of others did. I was one that did. I went from a 176 to a 205/210 shim. The Yamaha dealer can get these for you.

If you want to remove the manual compression release (I did) the plug you need to put in place of the compression release is part# is 90338-18064 . I removed it and the lever/cable assembly and have not had ANY need for it since.

From MOTOMAN 393:

Adjusting YZF's valves

YZ250f/400/426, WR250f/400/426 Valve Adjustment Procedure:

1.Remove seat, tank and shrouds

2.Remove breather hoses from top of engine cap.

3.Remove the spark plug.

4.Remove the top engine mount brackets (12mm, 14mm and hex wrench needed)

5.Remove the two engine cap screws (hex wrench needed).

6.Remove the engine cap taking care not to damage the gasket.

7.Remove the two timing caps from the left side of the engine crankcase (standard screwdriver)

8.Using a 14mm socket, align the timing mark ("I" not the "H") with the marks on the cover for the compression stroke (cam lobes should be facing away from each other). The marks on the cams should also match up to the top of the engine per WR or YZ timing.

9.Using a feeler gauge, you should be able to check all your valve clearance numbers.

10.Start with the manual specs and shove the feeler gauge under the cam lobes. If it won't go under, go down until it does. If it goes in to easy, go up. I beleive there should be a slight resistance when checking the correct clearance but it should slide under the lobe.

11.Compare your numbers with the manual's specs. If they are not in specification, then you will need to change out your shims.

Make sure you keep track of which clearance measurement goes with each valve as you will have to match them up with shim numbers if you need to adjust them. That is all you need to do to check your clearance. Now if you have to actually adjust your valves, then you need to keep reading.

Adjusting your valves:

1.Remove the chain tensioner on the back of the engine (8mm and 10mm)

2.It is a good idea to stuff some rags anywhere in the engine openings to help prevent dropping something down there. You should have an extend magnet handy just in case you do drop something.

3.Working in a criss cross pattern, remove the cam cap bolts (8mm, 4 on exhaust, 5 on intake).

4.Carefully, carefully, carefully lift off your cam caps. There is a halm moon retainer at the front of each cam. If you have one, use the extend magnet to grab it as you lift. Otherwise, be very aware of it. Also, there should be two guiding dowels on the bottom of each cam. Mine were frozen in the caps themselves. But if they are not, they could also drop out and down the engine.

5. Your cams should just lift up and forward. Carefully remove them from the chain. Do not let your chain drop down the engine. If you can, zip tie it or rubber band it so that it won't fall. Reason being is that it can come off the shaft down at the bottom of the engine.

6. Remove the compression release from the front of the engine. Take note of how the spring is setup for when you put it back on. Once the bolts are removed, it will slide out.

7.At this point, it is a good idea to have paper and pen ready to mark where the valve lift covers come out and go back in as well as keeping track of your shim numbers. You want to make sure you get the covers back in the same spots you took them out.

8. Carefully lift out the valve lifter covers. The shims are underneath these covers. Mine were stuck to the inside top of the covers with oil. But they are very small and could drop out and into the engine.

9. Once they are all out, match the shim number with your earlier clearance markings. Using the table in the manual, calculate what shims you need to install. It is easy to follow.

10.At this point, you will have to wait until you can get new shims from the dealer. Some carry them, some have to order them. Cover up your engine so no dirt gets in there.

Once your new shims arrive, carefully install them on top of the correct valves pressing them into their fittings with the NUMBERS FACING UP.

Note: On reassembly always put assembly lube on both sides of the adjusting shims and the buckets. Also coat the CAMs with assembly lube.

1. Put the valve lifter covers back into there original spots. Once fitted, you should be able to rotate them in their spots.

2. Install the compression release setup at the front of the engine. Make sure you have the proper 5mm free play upon the lever after you do this.

3. Install the cams making sure the timing marks on the cams are matched up to the engine top correctly per WR or YZ timing. The cam lobes should be facing away from each other when done.

4. This may take some pushing and pullin on the chain, make sure you do not dislodge it from the bottom shaft. Also make sure your timing mark in the crankcasecover has not moved.

5. Carefully install the cam retainers and cam caps. I found it easier to put the retainer on the cam first then putting the cam cap on. This may take a little time to find the exact position the cam is supposed to be in, but the cap won't fit on unless the cam is in the exact spot. Remember the guiding dowels on the bottom of the retainers.

6. Working in a criss cross pattern, install the cam cap bolts and tighten down to 10 Nms.

7. Before installing the chain tensioner, take a small standard screwdriver and put it in the end of the tensioner. With your finger on the push rod, twist the tensioner until it locks.

Install the tensioner. Take the screwdriver and slowly release rod until it stops. Do not force it once it stops. Make sure it did release and put the end bolt on.

8. Using the 14mm socket, turn over the engine a couple of times and re-allign the timing marks.

9. Re-check your valve clearance measurements. If they are still out of specs, redo the whole adjustment process.

10. Install the timing mark caps on the left side of the crankcase.

11. Install the engine cap making sure not to damage the gasket.

12. Install the engine cap bolts and tighten them down.

13. Install the top engine mount brackets, torque to specs.

14. Install the breather hoses.


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