Picked up an '03 YZ450F


51 replies to this topic
  • YzCas

Posted June 30, 2014 - 01:41 PM

#21

My biggest concern is hoe to set proper timing without the stock case cover..

I'm new to thumpers but I'm pretty mechanically inclined that's why I want to hear how you make out I'm learning some to.

  • mvrk10256

Posted June 30, 2014 - 01:43 PM

#22

Normally t her stock cover has the alignment marks. I am hoping something is cast on the actual case wall.

  • YzCas

Posted June 30, 2014 - 01:43 PM

#23

My biggest concern is hoe to set proper timing without the stock case cover..

Can't you just lay the bike on its side and take the cover off.

  • mvrk10256

Posted June 30, 2014 - 01:47 PM

#24

Like I said. Normally there is one alognment mark on the crank and another on the case to set TDC. Sincr I have solid aluminum case covers I dont have that window port and alignment mark.

  • YzCas

Posted June 30, 2014 - 01:50 PM

#25

Like I said. Normally there is one alognment mark on the crank and another on the case to set TDC. Sincr I have solid aluminum case covers I dont have that window port and alignment mark.

okay a case like this.
that's what their for HMS is it easy to set the timing through these holes.

Attached Thumbnails

  • 1404164919103.jpg


  • mvrk10256

Posted June 30, 2014 - 01:53 PM

#26

With that case setting timing is pretty straight forward. I have not pulled mone yet however I may have a flywheel weight and a spaced case. Its normally just 12 ocloc in relation to to the cylinder.

  • YzCas

Posted June 30, 2014 - 01:55 PM

#27

With that case setting timing is pretty straight forward. I have not pulled mone yet however I may have a flywheel weight and a spaced case. Its normally just 12 ocloc in relation to to the cylinder.

Ok that's good to know I have them on all my bikes I kinda figured theye were for timing but I need to read up on how to and why.

  • mvrk10256

Posted June 30, 2014 - 01:57 PM

#28

Its all in the manual. I just need the gaskets and I will get this thing back together ina matter of hours. Nice thing avout high end race bikes is they are made to come apart.

  • grayracer513

Posted June 30, 2014 - 02:03 PM

#29

Disregard the timing marks and use true TDC instead by probing for the piston with a screwdriver.



  • YzCas

Posted June 30, 2014 - 02:06 PM

#30

Its all in the manual. I just need the gaskets and I will get this thing back together ina matter of hours. Nice thing avout high end race bikes is they are made to come apart.

Well my friend I'm going out to ride since I'm talking kx I'll take my 13 450 out for an hour then let the kids ride when I get back. before you ask I have three 13S rmz 450 kx 450 2 yz 450s.

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  • mvrk10256

Posted June 30, 2014 - 02:06 PM

#31

Disregard the timing marks and use true TDC instead by probing for the piston with a screwdriver.


You can be a tooth off like that. I prefer timing marks.but ita a good sanity check. But I always hand turn the engine to make sure I got it assembled properly before I kick it over.

  • mvrk10256

Posted June 30, 2014 - 02:08 PM

#32

Well my friend I'm going out to ride since I'm talking kx I'll take my 13 450 out for an hour then let the kids ride when I get back. before you ask I have three 13S rmz 450 kx 450 2 yz 450s.



May want to invest in a mechanic

  • YzCas

Posted June 30, 2014 - 02:14 PM

#33

May want to invest in a mechanic

nope I can figure these out that's why I keep an 01 yzf450 I'm going to tear it down in the winter learn how to work on them. good luck. keep me posted.

  • grayracer513

Posted June 30, 2014 - 02:30 PM

#34

You can be a tooth off like that.

 

No, you can't.  Not if it's done right.



  • mvrk10256

Posted June 30, 2014 - 03:14 PM

#35

No, you can't. Not if it's done right.



  • mvrk10256

Posted June 30, 2014 - 03:26 PM

#36

Any make on this flywheel weight? 

 

 

Attached Thumbnails

  • 20140630_174846.jpg
  • 20140630_175258.jpg


  • grayracer513

Posted June 30, 2014 - 03:30 PM

#37

Nice work, but I don't recognize it.  Anyone else?



  • mvrk10256

Posted June 30, 2014 - 03:36 PM

#38

Its a quality piece and heavy. probably close to 8oz, but its hard to tell since its a bolt on. Also the center nut thing was a 5/8 or 16mm, which is kinda weird as most metric stuff is either 15 or 17. 



  • mvrk10256

Posted July 07, 2014 - 07:32 PM

#39

Well good news and bad news. Bad news is warped head = pressurized crank case. The purpose of this bike was to make a quick profit so it looks like a part out is immanent, unless i can score a cheap head. Good news is here is the walkthrough you guys were wanting. 

 

Most of the parts and the gasket kit:

eeHREAQl.jpg

 

Assembly Lube - nothing but the best. 

xqWFy86l.jpg

 

Putting the piston on first. Ring gaps were checked, and rings were positioned. A little assembly lube on the wrist pin and slide it all together. 

gP9hMill.jpg

 

Put a towel or tin foil around the piston when putting in the cir clips otherwise you will drop one into your bottom end. 

KamXyE6l.jpg

 

New jug gasket. 

R5qqlRCl.jpg

 

Torque the jug bolt (8mm) down to 10Nm

bvFIwxGl.jpg

 

Now stick in the other chain guide. 

NcVm9Xpl.jpg

 

Set TDC - Normally you have the cover on to do this, however since I lacked the stock cover I found that my TDC mark lined up with that casting mark. This is not guaranteed. 

n9ZJfzol.jpg

 

Put the head on. 

hyPHmp4l.jpg

 

Clean up the bolts  -  a little sandpaper and brake clean goes a long way. 

pss1CPhl.jpg

 

torquing instructions: Torque to 30Nm, remove, regrease, torque to 20Nm, do 2 x 90* torques - Bolts are 14mm. Make sure to put them down handtight first. 

omUgOgpl.jpg

lGWQRMbl.jpg

lGWQRMbl.jpg

ROYiixSl.jpg

1HRB6jGl.jpg



  • mvrk10256

Posted July 07, 2014 - 07:33 PM

#40

TDC check 1: drop a screwdriver down the spark hole and make sure engine is at true TDC

4cPAyPHl.jpg

VKlmZfPl.jpg

 

Install Exhaust Cam first. Make sure chain is tight running down to crank. 

JURZf6Kl.jpg

 

Wiggle in the Intake Cam. Note the dots. you want one at 12 oclock on each cam, and the other one at the valve cover gasket surface. Sanity check to make sure lobes are point out at 30* above valve gasket surface. 

d4Wv17fl.jpg

 

Shit pic but dont forget the cam guide thingy...

d4Wv17fl.jpg

 

Cam bolts in at 10Nm

BifLGMvl.jpg

 

Dont forget these guys. 

wqzXtLJl.jpg

 

And finally compress the tensioner, bolt it back on with a new gasket, and release it. Bolt in the retaining bolt. 

vwUCuBtl.jpg

 

And your done. Its preferable to start with a good head. 







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