03 450 HELP!


9 replies to this topic
  • -Biggins-

Posted November 30, 2013 - 10:12 PM

#1

Hey guys, I'm getting my 450 ready to sell. I noticed that the timing was way off when I took the valve cover off. So I timed it, piston at TDC, and then adjusted the valves. I got them in spec. Put it all back together, noticed that it had way more compression, but it wont start. Help

  • -Biggins-

Posted December 01, 2013 - 10:57 AM

#2

Anybody? It seems like it sounds different when I kick it over. Won't start. Anything guys?

  • shortburb

Posted December 01, 2013 - 05:39 PM

#3

The two variables you changed were timing and valve clearance. If timing is off it won't start. If valve clearance is too tight it won't run/hard to start.

Recheck those first

  • -Biggins-

Posted December 01, 2013 - 08:12 PM

#4

The two variables you changed were timing and valve clearance. If timing is off it won't start. If valve clearance is too tight it won't run/hard to start.
Recheck those first

yeah I set the timing and the clearances at top dead center on the flywheel, timed it, now I put it to TDC and check it, and the timing is WAY off. It sounded different when I started it. Going Tuesday to get some shims.

  • -Biggins-

Posted December 07, 2013 - 12:16 AM

#5

So the exhaust valves measured .27 mm and the intakes at .14 mm. Set the timing according to TDC on flywheel. Still won't start. Has visible spark, compression, air/fuel,( the plug was wet ), has timing, what am I missing?

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

Posted December 07, 2013 - 12:17 AM

#6

I know the exhaust valves are a little more than the clearance but is it that causing it to not start? It also back fires about every 10th kick.

  • vic2340

Posted December 07, 2013 - 07:37 AM

#7

My friend and I got the timing wrong by a little once, it was on his 03 crf450r. It wouldn't start. I think you have the same issue. Make sure your cam chain and cams are where they should be. One tooth difference and their is no way the bike will run.

  • -Biggins-

Posted December 07, 2013 - 12:26 PM

#8

My friend and I got the timing wrong by a little once, it was on his 03 crf450r. It wouldn't start. I think you have the same issue. Make sure your cam chain and cams are where they should be. One tooth difference and their is no way the bike will run.

I got it as close as I could. It was almost perfect. If you go one tooth up, it's too far, one tooth back it's just a little under the case.

  • vic2340

Posted December 07, 2013 - 07:15 PM

#9

Well that means your timing chain is super stretched, order an oem one pronto. They are like 25 bucks on rockymountainatv.com in there oem section.

  • -Biggins-

Posted December 07, 2013 - 07:54 PM

#10

Well that means your timing chain is super stretched, order an oem one pronto. They are like 25 bucks on rockymountainatv.com in there oem section.

will that make it not run? All I'm trying to do is make it run for the guy that wants to trade his yz 250 2006 :)





Related Content

Forums
Photo

Snake pit oct 30th by The Anvil


Dirt Bike   Dirt Bike Regional Discussion   California
  • Hot  293 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

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

Megabomb Fitment by 288yz450


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