what causes thrown rod? - Yamaha ATV Forum
 
LinkBack Thread Tools Display Modes
post #1 of 10 Old 02-10-2010, 11:59 PM Thread Starter
Junior Member
 
joey moheit's Avatar
 
Join Date: Dec 2009
Location: moore oklahoma
Posts: 25
what causes thrown rod?

i reacentley got another 03 raptor 660 and it had threw a rod through the cases i have replaced it but im wondering what caused this ? the oil pump works . i noticed a dent in the radiator but no leeks would that caus it to over heat and throw a rod ? the one way is great the clutch plate on the back was shattered . the piston and jug were stock and are again stock with high com piston 11.1-1 i dont want to start it and have it fall apart is there anything i should cheak first ?
joey moheit is offline  
Sponsored Links
Advertisement
 
post #2 of 10 Old 02-11-2010, 07:26 AM
Primo Member
 
motorhead's Avatar
 
Join Date: Jun 2007
Location: Northeast Ohio
Posts: 567
Did this engine have the hotrods crankshaft like explained in your other posts? Also was it an oem replacement or stroker crank? Fill us all in with as much info as possible.

686 JE 12.5:1 Ceramic coated piston/head
Megacycle X-4 cam Kibblewhite valves/springs
Pro-flow filter kit UPP intakes
Trailtech flywheel
Trinity stage IV Exhaust
Yukon gears +2 Arms +4.5 swingarm 450 shocks
motorhead is offline  
post #3 of 10 Old 02-11-2010, 08:05 AM
Crowd Control
 
diggerzmound's Avatar
 
Join Date: Oct 2002
Location: Nebraska
Posts: 8,387
Garage
Send a message via AIM to diggerzmound Send a message via Yahoo to diggerzmound
Usually over-revving. Big cams let the engine spin faster and high compression puts more stress on things.

01' Raptor 720, Stage 2, FCR'd
97' 250 Vitos Blaster
06' Rhino 450
94' Banshee T-5's, Vforce, ported, Cool Head, 2-1
06' Wolverine 450 - Stock!
06' LTZ 440
94' Vmax4 750, 96' 600 MountainMax
06' Vmax 1200
diggerzmound is offline  
Sponsored Links
Advertisement
 
post #4 of 10 Old 02-11-2010, 01:09 PM
Primo Member
 
leveldrummer's Avatar
 
Join Date: Jan 2008
Posts: 2,583
simple things like never changing the oil, never cleaning the air filter and stuff can easily blow an engine up, runnign with no oil, or no water, or even sometimes, it just happens, machines and going to fail, and sometimes they fail catastrophically... which is the perfect definition of a thrown rod. something broke, and a chain reaction leads to all hell breaking loose.
leveldrummer is offline  
post #5 of 10 Old 02-11-2010, 01:14 PM Thread Starter
Junior Member
 
joey moheit's Avatar
 
Join Date: Dec 2009
Location: moore oklahoma
Posts: 25
the motor was blown when i got it and it was a stock crank oem.
joey moheit is offline  
post #6 of 10 Old 02-12-2010, 03:25 AM
Primo Member
 
Join Date: Jan 2003
Location: Nebraska
Posts: 1,924
I would say over reving is the biggest problem.

03 Limited Edition Raptor Hot Rods 720cc Stroker, Megacycle x-4 cam, Sparks 6X Big Core Exhaust, 35mm Keihin FCR's.

97 Yamaha Banshee - F.A.S.T. Dune Ported 4mill Stroker, CPI Pipes, Keihin PWK33's, Direct Drive Lockup,
158 main jets, CEL Needles on the middle clip, 45 Pilots.
03LimitedEditionRaptor is offline  
post #7 of 10 Old 02-12-2010, 07:34 PM
Junior Member
 
Join Date: Mar 2009
Posts: 17
Quote:
Originally Posted by leveldrummer View Post
simple things like never changing the oil, never cleaning the air filter and stuff can easily blow an engine up, runnign with no oil, or no water, or even sometimes, it just happens, machines and going to fail, and sometimes they fail catastrophically... which is the perfect definition of a thrown rod. something broke, and a chain reaction leads to all hell breaking loose.
please explain how a dirty air filter can cause a rod to snap? i have heard it all now....over reving the motor causes rods to snap end of story
heater is offline  
post #8 of 10 Old 02-13-2010, 10:39 PM
Primo Member
 
Join Date: Jan 2003
Location: Nebraska
Posts: 1,924
Quote:
Originally Posted by heater View Post

please explain how a dirty air filter can cause a rod to snap? i have heard it all now....over reving the motor causes rods to snap end of story
The dirt builds up on the bottom of the cylinder. Pretty soon the bottom of the cylinder is necked clear down. Then as the conectiong rod is rotating, the conecting rod hits the hard dirt ring.

03 Limited Edition Raptor Hot Rods 720cc Stroker, Megacycle x-4 cam, Sparks 6X Big Core Exhaust, 35mm Keihin FCR's.

97 Yamaha Banshee - F.A.S.T. Dune Ported 4mill Stroker, CPI Pipes, Keihin PWK33's, Direct Drive Lockup,
158 main jets, CEL Needles on the middle clip, 45 Pilots.
03LimitedEditionRaptor is offline  
post #9 of 10 Old 02-13-2010, 11:08 PM
Primo Member
 
leveldrummer's Avatar
 
Join Date: Jan 2008
Posts: 2,583
Quote:
Originally Posted by heater View Post
Quote:
Originally Posted by leveldrummer View Post
simple things like never changing the oil, never cleaning the air filter and stuff can easily blow an engine up, runnign with no oil, or no water, or even sometimes, it just happens, machines and going to fail, and sometimes they fail catastrophically... which is the perfect definition of a thrown rod. something broke, and a chain reaction leads to all hell breaking loose.
please explain how a dirty air filter can cause a rod to snap? i have heard it all now....over reving the motor causes rods to snap end of story
when all the sticky oil has dirt packed into it, then dust gets through, into the cylinder, scratches it up, causes lock up, and catastrophic engine failure, sure it wont just cause the crank to snap, but it can sure ruin an engine, and cause failure, which will lead to a crank breaking etc...

point is, lots of things cause engines to blow,
leveldrummer is offline  
post #10 of 10 Old 02-14-2010, 02:18 PM Thread Starter
Junior Member
 
joey moheit's Avatar
 
Join Date: Dec 2009
Location: moore oklahoma
Posts: 25
the silinder and piston were dameged. but i was just wondering i realy dont want that to happen to me . i took it out the other day it did realy well till i tried to climb a 9' hill it started to slow down so i hit the throttle and almost fliped it . i got it down and when it died i restarted it and it ran good but i knew something was wrong cheaked the timeing and my woodruf key was sheered the flywheel was spining every once and a while it would catch . i built the bottom end and put the flywheel on but dident torque it up becaus the top end wasent on and its easier to get it torqued up as a compleat motor for me anyways . but i got a key today and its back up and running .
joey moheit is offline  
Reply

Tags
crank rod, thrown rod

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Yamaha ATV Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
thrown off ex riders hondablows Yamaha YFZ450/450R (2004-Present) 1 11-08-2003 11:07 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome