Yamaha Discussions about Yamaha ATVs.

2006 yfz450 wont start

Thread Tools
 
Search this Thread
 
  #1  
Old 03-06-2010, 04:38 PM
K F X STEVE480's Avatar
Weekend Warrior
Thread Starter
Join Date: Mar 2008
Posts: 21
Likes: 0
Received 0 Likes on 0 Posts
Default 2006 yfz450 wont start

today i was riding and i wasin fourth gear and then it just died and started to roll, tryed to pop start it while it was rolling and all it did was keep turning over, i have a high compression head, there is oil in it and everything else is good, if i try to start it i can hold the start and it will just keep turning over but seems like it lost compression because i can also push it while in gear and it has some but notmuch compression? i just need some suggestions, can it be a blown seal? rings or whole top end?
 
  #2  
Old 03-06-2010, 10:32 PM
Kevin R.'s Avatar
Trailblazer
Join Date: Dec 2008
Location: Denton, Texas
Posts: 100
Likes: 0
Received 0 Likes on 0 Posts
Default

Have you done a comprssion test? If it's lost compression, it's time to dig into the topend. Are you shure when you are pushing it the piston is pumping? If not you may have broke the crank or a gear.
 
  #3  
Old 03-07-2010, 07:55 AM
TRX1000's Avatar
Range Rover
Join Date: Nov 2009
Location: in the middle of nowhere North Carolina
Posts: 142
Likes: 0
Received 0 Likes on 0 Posts
Default

you also want to check spark,wiring conections,carb&fuel...etc
 
  #4  
Old 03-07-2010, 01:40 PM
K F X STEVE480's Avatar
Weekend Warrior
Thread Starter
Join Date: Mar 2008
Posts: 21
Likes: 0
Received 0 Likes on 0 Posts
Default

yea ican feel it on the head pumping and air will come out of exhaust when pressing electric start, when i push it in gear it still has compression but not as much as it should, and it you can just hear the electric start going fast with not much compression, if the valves went would it lose compression



Originally Posted by Kevin R.
Have you done a comprssion test? If it's lost compression, it's time to dig into the topend. Are you shure when you are pushing it the piston is pumping? If not you may have broke the crank or a gear.
 
  #5  
Old 03-07-2010, 02:39 PM
TRX1000's Avatar
Range Rover
Join Date: Nov 2009
Location: in the middle of nowhere North Carolina
Posts: 142
Likes: 0
Received 0 Likes on 0 Posts
Default

mabey it skipped timing? check your cam timing, valve clearences, and get a REAL compression test, and if possible a cylinder leakdown test.
 
  #6  
Old 03-07-2010, 05:14 PM
K F X STEVE480's Avatar
Weekend Warrior
Thread Starter
Join Date: Mar 2008
Posts: 21
Likes: 0
Received 0 Likes on 0 Posts
Default

i know it lost most compression because i can push it pretty easily in gear, it has compression but barley any to what it should have, if the valves went would it make it lose compression and not start?, if the rings went would it lose all compression and not start? or what else can it be, basically before it happened everything was perfect, it ran strong, went fast and then was down shifting then it just stalled, and wouldn't start its nothing electrical its just something made it lose compression and it wont fire up


Originally Posted by TRX1000
mabey it skipped timing? check your cam timing, valve clearences, and get a REAL compression test, and if possible a cylinder leakdown test.
 
  #7  
Old 03-07-2010, 08:02 PM
TRX1000's Avatar
Range Rover
Join Date: Nov 2009
Location: in the middle of nowhere North Carolina
Posts: 142
Likes: 0
Received 0 Likes on 0 Posts
Default

Either valves,rings,or headgasket. Or you blew a hole in the top of your piston...but thats not so common, unless you were riding at WOT and it was running lean.
 
  #8  
Old 03-07-2010, 09:36 PM
91Warrior357's Avatar
Pro Rider
Join Date: May 2008
Location: Purcellville.
Posts: 1,860
Likes: 0
Received 0 Likes on 0 Posts
Default

most likely rings are toast or headgasket pewped, would be rare for something to happen in the vavletrain without a noise, rings are usually silent when they give out
 
  #9  
Old 03-11-2010, 08:18 PM
danatack's Avatar
Range Rover
Join Date: Dec 2009
Location: cheyenne wyoming
Posts: 102
Likes: 0
Received 0 Likes on 0 Posts
Default

yes i would agree with rings or head gasket. so tear her down, you know you want to trick it out more. and we find when we tear our engines apart it's an excuse to go back back together with better, faster, parts...lol.
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Ltz250goon
Sport Quads
1
12-03-2015 07:51 PM
VRRRRT
Chinese Quads
3
06-20-2015 03:47 PM
BillinIll
Polaris
8
06-19-2015 01:39 PM
1000gade
ATV Videos
0
05-27-2015 12:37 PM
Joe Paul
General Chat
1
05-27-2015 09:04 AM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


Quick Reply: 2006 yfz450 wont start



All times are GMT -5. The time now is 06:14 AM.