Picked up an '03 YZ450F


51 replies to this topic
  • mvrk10256

Posted June 11, 2014 - 12:34 PM

#1

Pretty excited. Traded my YZ125 for it. So my out of pocket was around $1k. 

 

Oil looks like chocolate milk, carb leaks, but it has pretty much every major aftermarket thing on it you can imagine, and runs quite well. At least till the gas drains out of the bowl. Rebuild time.... Lets play spot the aftermarket parts.. What do you see...

 

rTc92oVl.jpg



  • Mike in OK

Posted June 11, 2014 - 01:09 PM

#2

I see lots of stickers!

  • mvrk10256

Posted June 20, 2014 - 05:10 PM

#3

Day 1:

-ordered all the wp parts

-rebuilt the carb - clogged pilot jet and general crud

-rebuilt petcock - now the tank will actually hold gas. 

 

Pics of stuff:

 
I75s2e0l.jpg
FGRwXVFl.jpg
532hTEPl.jpg
pZV69DPl.jpg
xenwz4Wl.jpg
XACfLiYl.jpg
c2Jxb2dl.jpg
1BsTAYUl.jpg
G9poE1Al.jpg
S4mFK03l.jpg
WdQGrrNl.jpg
ctOCOYol.jpg
30AoQ59l.jpg
FEzhjbvl.jpg
ID8TkSUl.jpg


  • mvrk10256

Posted June 20, 2014 - 05:31 PM

#4

hJOkFbNl.jpg
u19rcvJl.jpg
0VHV6fYl.jpg
xY8qyS7l.jpg
Y7qHp4Il.jpg
JqoyR54l.jpg
0QzIGnql.jpg
 
my helper goofing around later:
FWoSecxl.jpg


  • mvrk10256

Posted June 26, 2014 - 05:59 PM

#5

Got some more work done today. 

 

Mostly just the waterpump. Damn that old one was nasty. The impellar shaft was all chewed up. So hopefully should get the carb and stuff back together tomorrow and fire her up. 

 

The mystery oil was Valvoline VR-1 from another thread.

 

9cQjlHxl.jpg

 

Clutch was in immaculate condition, as were all the gaskets 

 

YdnhACSl.jpg

pDOiaQ9l.jpg

Ct75NaVl.jpg

YFNaRDnl.jpg

 

yuk

K0Qn53Ol.jpg

pGxmRhCl.jpg



  • mvrk10256

Posted June 28, 2014 - 02:46 PM

#6

Well day 3 is a mix of good and bad...

 

Good:

got the carb working properly

got everything reassembled

found out I have stage 1 Hot Cams

found out I have a HotRods rotating assembly

found out I have a vertex piston (high comp?)

 

Bad:

blown headgasket. 

had to tear it all down again

stripped screw in head. 

 

Hopefully get an extractor set this week to remove the screw, and order some new gaskets. 

X2Im3Mol.jpg

14UtuF3l.jpg

ItoC5hVl.jpg

 

j643Wtil.jpg

2viEbXSl.jpg

 

JcOIbDul.jpg

fDCpvHBl.jpg

v9wGioXl.jpg

 

w3p9Cutl.jpg

1kDDb7Bl.jpg

o6ZpHmdl.jpg



  • mvrk10256

Posted June 28, 2014 - 02:59 PM

#7

You guys think the piston is good to reuse?



  • YzCas

Posted June 29, 2014 - 10:09 AM

#8

You guys think the piston is good to reuse?

yes but after being apart why not hone the cylinder and go for piston and rings your already there.

I don't care what people say if it's nicaseal just run a ball hone through it real quick.

I used to race boats two stroke engine I ran ball hone through a lot.

When I was young I did it on my mx bikes to take the lip off the top of the cylinder if it has one
oil the shit out of it and
hone it it will be fine.

while your in there you should debur the cylinder don't open the ports just smooth them out.

  • grayracer513

Posted June 29, 2014 - 10:36 AM

#9

Nothing that shows in your pictures gives any information about the condition of the piston or bore walls, so there's no way to tell.  The crank was replaced at least once; that one's from Hot Rods.

 

Judging by the look of the cam journals, the previous owner wasn't a big fan of frequent oil changes. 



  • mvrk10256

Posted June 29, 2014 - 11:25 AM

#10

yes but after being apart why not hone the cylinder and go for piston and rings your already there.

I don't care what people say if it's nicaseal just run a ball hone through it real quick.

I used to race boats two stroke engine I ran ball hone through a lot.

When I was young I did it on my mx bikes to take the lip off the top of the cylinder if it has one
oil the shit out of it and
hone it it will be fine.

while your in there you should debur the cylinder don't open the ports just smooth them out.

 

I will absolutely hone the cylinder. But on a bike I am not sure if I will keep I do not want to spend $200 on a new piston kit. Especially considering the old one is in good shape. 

 

 

Nothing that shows in your pictures gives any information about the condition of the piston or bore walls, so there's no way to tell.  The crank was replaced at least once; that one's from Hot Rods.

 

Judging by the look of the cam journals, the previous owner wasn't a big fan of frequent oil changes. 

 

Ya. They are not perfect, but judging from the amount of water in the oil, and general shittyness I will be doing several oil changes to get everything out. Hard to take proper pics of bore.

 

7vLE0h9l.jpg



Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • grayracer513

Posted June 29, 2014 - 06:09 PM

#11

I'm more concerned about the piston.

  • mvrk10256

Posted June 30, 2014 - 05:55 AM

#12

I'm more concerned about the piston.

based on what?



  • grayracer513

Posted June 30, 2014 - 06:25 AM

#13

Based on the fact that there aren't any pictures of the skirts.  You'll also need to carefully gauge the wear in the ring grooves to see if they are tapered open from inside to out.  Too much clearance allows the rings to twist at the top and bottom of the stroke, accelerating wear on both rings and bore.



  • mvrk10256

Posted June 30, 2014 - 06:27 AM

#14

I will use a feeler gauge on the rings tonight. 

QA0xOYHl.jpg

MDg6Fsnl.jpg

CloQErGl.jpg



  • mvrk10256

Posted June 30, 2014 - 12:33 PM

#15

Piston is confirmed by vertex as a 13.5:1 high comp unit. You can tell by the bump in the middle. 

 

v9wGioXl.jpg



  • grayracer513

Posted June 30, 2014 - 01:24 PM

#16

Piston "looks" ok.  measure the clearance after you clean the bore up with a brush hone. 

 

http://www.thumperta...d/#entry3565759



  • YzCas

Posted June 30, 2014 - 01:27 PM

#17

Piston "looks" ok. measure the clearance after you clean the bore up with a brush hone.

http://www.thumperta...d/#entry3565759

What are you waiting for put that bad boy back together.

  • mvrk10256

Posted June 30, 2014 - 01:30 PM

#18

What are you waiting for put that bad boy back together.


Head gasket and jug gasket shipped out today. Didnt know I needed it till yesterday.

  • YzCas

Posted June 30, 2014 - 01:33 PM

#19

Head gasket and jug gasket shipped out today. Didnt know I needed it till yesterday.

Okay take your time doing it follow the manual to the t any questions call or jump on tt and ask don't rush it let me know how you make out lol.

  • mvrk10256

Posted June 30, 2014 - 01:36 PM

#20

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





Related Content

Forums
Photo

Chubby dad, looking at bikes , First trip to the orange/black forum ! by Slow_ride


Dirt Bike   Make / Model Specific   KTM   250-530 EXC/MXC/SXC/XC-W/XCR-W (4-Strokes)
  • Hot  28 replies
Forums
Photo

2016 YZ450 by CaptainKnobby


Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  59 replies
Reviews

Yamaha YZ450F 2017 by Chris.GVS


Yamaha YZ450F 2017
  • - - - - -
  • 0 reviews
Forums
Photo

Megabomb Fitment by 288yz450


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 1 reply
Forums
Photo

yz250x vs 450 4t comparisons (preferably desert riding) needed by JakeNorthrupYZ450F


Dirt Bike   Make / Model Specific   Yamaha   Yamaha 2-Stroke
  • 9 replies
 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.