Yamaha Sport ATV Forum

Cracked crankcase

This is a discussion on Cracked crankcase within the Yamaha YFZ450/450R (2004-Present) forums, part of the Performance /Technical category; What is the YFZ450 crank case made of? Aluminium? Can it be welded?. A small cracked appeared when my chain came off and got stuck ...


Go Back   Yamaha ATV Forum > Performance /Technical > Yamaha YFZ450/450R (2004-Present)

Reply
 
LinkBack Thread Tools Display Modes
Old 01-14-2012, 09:46 PM   #1
Junior Member
 
Join Date: Nov 2010
Posts: 4
View flippinz's Photo Gallery(0)
Default Cracked crankcase

What is the YFZ450 crank case made of? Aluminium? Can it be welded?. A small cracked appeared when my chain came off and got stuck between the sprocket and frame. Its leaking oil from it, pretty seriously. I am going to try J-B weld it too if all else fails. Its hardly an inch long.

Any ideas?
flippinz is offline   Reply With Quote
Old 01-20-2012, 01:21 AM   #2
Junior Member
 
Join Date: Nov 2010
Posts: 4
View flippinz's Photo Gallery(0)
Default

JB Weld worked but my focus now turns to the oil leaking form the oil seal where the clutch cable connects to a shaft. Not sure the seal can be replaced from the top, so my only option is to make another seal that fits on top and use/mod the little plate that hold the spring in place to help seal it.
Some more JB weld and maybe gasket sealer and I should be up and running with a motor that Yamaha has written off.
I will get a good camera and document the fix once successful. Anyone with something similar let me know I am open for ideas.
flippinz is offline   Reply With Quote
Old 01-25-2012, 10:57 AM   #3
Member
 
Join Date: May 2010
Location: delaware county pa
Posts: 91
View mz9699's Photo Gallery(0)
Default

JB weld dude? seriously? get a case half off ebay, fix it right, and make the rest of us honkies proud!!!!!
mz9699 is offline   Reply With Quote
Old 01-25-2012, 11:04 AM   #4
Junior Member
 
Join Date: Jan 2012
Posts: 2
View yfzKalvin's Photo Gallery(0)
Default

The aluminum case can be welded, but it would probably be cheaper to find a used one. I would only use JB weld for a temporary fix. It will probably work for a while, if you cleaned the area really really well. but don't consider it a permanent fix.
__________________
2008 Raptor SEII
2006 YFZ450
2008 Raptor 250
2000 Warrior
yfzKalvin is offline   Reply With Quote
Old 01-26-2012, 01:46 PM   #5
Junior Member
 
Join Date: Nov 2010
Posts: 4
View flippinz's Photo Gallery(0)
Default Fixed

JB weld worked for the crack, however with the new seal it still leaks a bit. I glued the edge with silicone and that stopped the leak. Taking the engine apart to fix a small leak is not worth it. This fix need to last at least half a ride And Id be happy to do it everytime. labour cost is $NZ80-100/ hr, + parts. I can buy a complet bike o fthe same year at the price a rebuild whould cost me.

Engineering shop could weld it but again the seal is no longer sealing as the crack makese the housing not 100% round.

I will be riding the 450 hard this year and plan a complete rebuild by the end of the year. (If nothing else breaks)

I may buy a new (2008) Kawasaki KXF450 and use the Yamaha as backup. Or vice versa.
flippinz is offline   Reply With Quote
Old 01-26-2012, 02:11 PM   #6
Junior Member
 
Join Date: Jan 2012
Posts: 1
View jsncallahan's Photo Gallery(0)
Default

Quote: Originally Posted by flippinz View Post
What is the YFZ450 crank case made of? Aluminium? Can it be welded?. A small cracked appeared when my chain came off and got stuck between the sprocket and frame. Its leaking oil from it, pretty seriously. I am going to try J-B weld it too if all else fails. Its hardly an inch long.

Any ideas?
i have used jb weld on some small wholes and cracks seemed to work fine the case is usually some kind of cast alluminum and is hard to get clean enough to get a good weld it is possible if you know the right guy that knows how to weld alluminum
jsncallahan is offline   Reply With Quote
Old 02-03-2012, 08:59 AM   #7
Member
 
Join Date: May 2010
Location: delaware county pa
Posts: 91
View mz9699's Photo Gallery(0)
Default

even if you got it clean enough to weld you're going to melt the shift shaft seal. it only takes about an hour to get the motor out and might takeanother three hours to swap out the case. The beautiful thing about this bike is when you split the case the whole trans. assembly stays in the right side so it's just a matter of splitting it and replacing the left side. I'm not a mechanic but I did it and it wasn't that bad.......
mz9699 is offline   Reply With Quote
Old 02-03-2012, 09:28 AM   #8
Senior Member
 
carsonmx114's Avatar
 
Join Date: Feb 2012
Posts: 165
View carsonmx114's Photo Gallery(0)
Default

Also yamaha doesn't sell just that side. they come as a set, and I would guess that if you look for used ones you will find alot of good right sides but few left ones for the same reason. new crankcase assembly is $399. Keep in mind that the new case won't have any bearings or seals in it either. The seal is replaceable from the top but you will have to take the clutch cover off and remove the clutch pressure plate to get the arm out of the case.
carsonmx114 is offline   Reply With Quote
Old 02-03-2012, 05:46 PM   #9
Member
 
Join Date: May 2010
Location: delaware county pa
Posts: 91
View mz9699's Photo Gallery(0)
Default

Yeah, it is tough to find just the left side and you usually will have to buy both sides but you don't necessarily have to use both sides. Really, you should use both sides as a set because they are line bored as a set but I just did one side and had no problems and I was lucky to find a left side. As far as bearings all u need are the right size sockets, maybe a drill, some dry ice and a propane torch. Sweating them is the best way since there is no banging involved but you have options. as far as JB weld........that's a temporary fix that could fail while you are riding and cause a major catastrophe.
mz9699 is offline   Reply With Quote
Old 11-15-2012, 08:38 PM   #10
Junior Member
 
Join Date: Nov 2012
Posts: 1
View brandonYFZ's Photo Gallery(0)
Default

It can be welded My son in law had his broken right off his and we got it welded for 20$
brandonYFZ is offline   Reply With Quote
Reply

Lower Navigation
Go Back   Yamaha ATV Forum > Performance /Technical > Yamaha YFZ450/450R (2004-Present)


Search tags for this page

yfz 450 crankcase

,
sealing crack in crankcase with silicone
,
yfz 450 left side crankcase
,
replace crank case gasket on yfz 450
,
weld or glue four wheeler crank case
,
yamaha four wheeler 450 cracked cover
,
2004 yfz 450 crankcase
,
2004 yfz 450 left crankcase
,
yfz case broke where clutch rod goes in
,
are 4 wheeler engine cases weldable
,
yamaha yfz 450 clutch shaft housing cracked
,
can you jb weld yamaha yfz case
Click on a term to search our sites for related topics.

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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


Similar Threads
Thread Thread Starter Forum Replies Last Post
07 crankcase with 05 jug stewdog Yamaha YFZ450/450R (2004-Present) 1 09-20-2011 06:30 PM
Crankcase stewdog Yamaha YFZ450/450R (2004-Present) 1 08-31-2011 09:53 PM
Crankcase Venting ?????? Bad ass 450 Yamaha YFZ450/450R (2004-Present) 0 08-26-2004 09:06 PM
TPS is cracked... see pic Jeepin 660 Yamaha YFZ450/450R (2004-Present) 7 06-30-2004 04:06 PM
crankcase???????? WhiteBrosRaptor Yamaha YFM660R Raptor (2001-2005) 0 04-11-2003 12:37 PM

» Discount Tire
Motosport.com

Powered by vBadvanced CMPS v3.2.2

All times are GMT -5. The time now is 03:49 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.