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lehmbeezy

2003 yzf450 leak?

5 posts in this topic

Hey guys so I'm going to buy a 2003 yzf450 for 1400,looks like great condition seller claims it was just rebuilt but the head gasket was reused so it's leaking coolant out of the overflow I was thinking of repairing it myself either with a new big bore cylinder kit,or even just the gasket, basically I'm just wondering if this sounds like something else is up with the bike or if it'll Just be a easy fix, also I've never rebuilt a top end before, I'm mechanicaly inclined with cars am I biting off more than I can chew or should I be fine?

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Well, if he didn't know or care better than to reuse the head gasket, his "rebuild" could be a can of worms. 

 

Coolant being exhausted from the overflow is normal under 3 circumstances:

  • Idling too long (no air flow over the radiators)
  • Extended time in tight or technical low speeds sections (same problem)
  • Overfilling the radiators (coolant will expand and force itself out if filled higher than the  tops of the core tubes)

Pretty much anything else is abnormal, and a head gasket will do it every time.

 

Get a manual, read it, follow it.  You'll be alright.  Leave the bike mostly stock, ride it a while, sell it for something newer, and modify that. 

 

http://api.viglink.com/api/click?format=go&jsonp=vglnk_146558862448310&key=fd4d0c8927dbf2331e83bbda32ac7c21&libId=ipa5mahr010004is000DL1ob0he00va9my&loc=http%3A%2F%2Fwww.thumpertalk.com%2Ftopic%2F378677-common-threads-look-here-1st-mods-maintenance-common-issues-and-faqs%2F&v=1&out=http%3A%2F%2Fwww.yamaha-motor.eu%2Feu%2Fservices%2Fowner-manuals%2Findex.aspx&title=Common%20Threads%3A%20Look%20here%201st!%20Mods%2C%20Maintenance%2C%20Common%20Issues%20and%20FAQ%27s%20-%20YZ%20400%2F426%2F450%20-%20ThumperTalk&txt=http%3A%2F%2Fwww.yamaha-mo...uals%2Findex.aspx

 

http://api.viglink.com/api/click?format=go&jsonp=vglnk_146558863693611&key=fd4d0c8927dbf2331e83bbda32ac7c21&libId=ipa5mahr010004is000DL1ob0he00va9my&loc=http%3A%2F%2Fwww.thumpertalk.com%2Ftopic%2F378677-common-threads-look-here-1st-mods-maintenance-common-issues-and-faqs%2F&v=1&out=http%3A%2F%2Fwww.yamahaownershandbook.com.au%2F%3Fr%3D0&title=Common%20Threads%3A%20Look%20here%201st!%20Mods%2C%20Maintenance%2C%20Common%20Issues%20and%20FAQ%27s%20-%20YZ%20400%2F426%2F450%20-%20ThumperTalk&txt=http%3A%2F%2Fwww.yamahaown...ook.com.au%2F%3Fr%3D0

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Well, if he didn't know or care better than to reuse the head gasket, his "rebuild" could be a can of worms.

Coolant being exhausted from the overflow is normal under 3 circumstances:

  • Idling too long (no air flow over the radiators)
  • Extended time in tight or technical low speeds sections (same problem)
  • Overfilling the radiators (coolant will expand and force itself out if filled higher than the tops of the core tubes)
Pretty much anything else is abnormal, and a head gasket will do it every time.

Get a manual, read it, follow it. You'll be alright. Leave the bike mostly stock, ride it a while, sell it for something newer, and modify that.

http://api.viglink.com/api/click?format=go&jsonp=vglnk_146558862448310&key=fd4d0c8927dbf2331e83bbda32ac7c21&libId=ipa5mahr010004is000DL1ob0he00va9my&loc=http%3A%2F%2Fwww.thumpertalk.com%2Ftopic%2F378677-common-threads-look-here-1st-mods-maintenance-common-issues-and-faqs%2F&v=1&out=http%3A%2F%2Fwww.yamaha-motor.eu%2Feu%2Fservices%2Fowner-manuals%2Findex.aspx&title=Common%20Threads%3A%20Look%20here%201st!%20Mods%2C%20Maintenance%2C%20Common%20Issues%20and%20FAQ%27s%20-%20YZ%20400%2F426%2F450%20-%20ThumperTalk&txt=http%3A%2F%2Fwww.yamaha-mo...uals%2Findex.aspx

http://api.viglink.com/api/click?format=go&jsonp=vglnk_146558863693611&key=fd4d0c8927dbf2331e83bbda32ac7c21&libId=ipa5mahr010004is000DL1ob0he00va9my&loc=http%3A%2F%2Fwww.thumpertalk.com%2Ftopic%2F378677-common-threads-look-here-1st-mods-maintenance-common-issues-and-faqs%2F&v=1&out=http%3A%2F%2Fwww.yamahaownershandbook.com.au%2F%3Fr%3D0&title=Common%20Threads%3A%20Look%20here%201st!%20Mods%2C%20Maintenance%2C%20Common%20Issues%20and%20FAQ%27s%20-%20YZ%20400%2F426%2F450%20-%20ThumperTalk&txt=http%3A%2F%2Fwww.yamahaown...ook.com.au%2F%3Fr%3D0

So it's possible.hes a idiot and it's just doing what its suppose to? And I'm not into upgrading this thing just need a bike to get out there and rise with my girlfriend on, lol thanks for the advice I thibk I'm gonna give it a go

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If he reused the head gasket, he's an idiot.  If you don't replace it, well....

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If he reused the head gasket, he's an idiot. If you don't replace it, well....

so I was looking online and found a big bore kit with full cylinder and piston for 400$, gonna just replace the whole thing, dumb question but is there anything else that the "top end" consist of? Or is that a total top end rebuild?

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