coolant overflow.....normal?

10 replies to this topic
  • afpilot

Posted June 19, 2004 - 08:10 PM


So I have a new 04 450f and after it warms up it starts overflowing coolant from the tube at the bottom of the bike beside the fuel vent tube. I haven't seen this before...Is this normal?......I haven't touched the bike other than just cranking and letting it idle for a little while. :thumbsup:

  • onewaymitch

Posted June 19, 2004 - 10:19 PM


it is a water pump seal that is the problem your dealer should be familiar with the problem and repair it for you (mine did)

  • yathump

Posted June 20, 2004 - 03:47 AM


What exactly do you consider a little while? These bikes will get hot without any airflow through the radiators causing the rad. to overflow.

  • Bergi600

Posted June 24, 2004 - 11:19 AM



a little while of idling is too long.....these modern four strokes overheat realy easy when standing still!!!! start your engine and warm it up while riding!!!!

  • afpilot

Posted June 25, 2004 - 05:07 PM


I haven't let it idle for more than 5-10 minutes tops.
But with no air flow and no fan I can see where it would get hot fast.

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  • logansowner

Posted June 25, 2004 - 05:39 PM


I haven't let it idle for more than 5-10 minutes tops.
But with no air flow and no fan I can see where it would get hot fast.

I have seen these bikes start to spew coolant after idling for less then 3 minutes, it's crazy, but thats the price you pay for having an engine that runs at the limit. :thumbsup:

  • chrome-crf

Posted June 25, 2004 - 05:46 PM


Yeah 5-10 minutes is way too long to let it sit and idle. There is nothing wrong with your bike. Keep it moving and it wont have a problem. Another tip is after it spews a little coolant don't fill it back up to the top. Leave it a little below the top to leave more room for expansion. It will help keep it from overflowing so soon :thumbsup:

  • 40oz2Freedom

Posted June 25, 2004 - 08:32 PM


good to hear! :thumbsup: mine does the same thing.

  • grayracer513

Posted June 25, 2004 - 10:02 PM


First, be sure that it's coming out of the radiator overflow tube. Anything else is a must fix leak. Otherwise, if there's anything wrong at all, it could be a weak cap, idling too long, or simply an overfilled system.

If you fill the system clear to the top when it's cold, it will have to overflow as it heats up, since the coolant expands. Try filling it, ride it as usual. AFTER IT COOLS, check the level. It should be down to just over the radiator core tubes. Leave it there and ride again, watching to see if it still pushes coolant out. If you're still suspicious, swap caps with a buddy and see if your problem moves to his bike.

Four strokes don't like to idle for anywhere near as long as 2 strokes without air over the radiator. Five minutes isn't too bad, but 10 is asking for it.

  • afpilot

Posted June 26, 2004 - 09:32 AM


:cheers:Thanx alot guys....
My next concern is which exhaust system to use....I want the shortest can I can get with some good performance gain. I actually like the harder hit of the 03 450f so more bottom end would be cool. :thumbsup:

  • B86_Racer

Posted June 26, 2004 - 10:20 AM


I would recommend a system with a lowboy header...

The only reason I say that is because with the lowboy header, they can make the can just barely stick out past the # plate (or maybe even stick it behind the # plate). The Thunder Alley pipe I used to have was like this and it had AWESOME power gains and I loved how the pipe just barely stuck out past the # plate. White brothers Carbon Pro I think is like that as well? Either way, the Thunder Alley is definitely cheaper... but FYI, it is LOUD.

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