2002 Yz 426f

7 replies to this topic
  • HMAZ

Posted April 09, 2008 - 02:02 PM


2002 YZ426f , after a minute or so at idle a little anti freeze comes out of the over flow is this normal?

  • JS264

Posted April 09, 2008 - 02:11 PM


Yes, that is because it is getting freakin hot from not getting any air through the radiators.

  • Slinkyman16

Posted April 09, 2008 - 03:03 PM


this is normal.. the early yz started to overheat very fast..

  • ClayKann

Posted April 09, 2008 - 03:27 PM


my 02 yzf250 doesnt overheat that quick i can let it idle on the stand for over a minute in 90+ heat. Must be something with the 426's.

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Posted June 17, 2008 - 05:49 PM


I had that problem with my '02 426 the bike isn't meant to idle for a long time. I put a a bigger water pump on mine and engine ice collant. cooled it down like 15 degrees. i really needed since i ride trails most of the time.

  • grayracer513

Posted June 17, 2008 - 07:07 PM


It is pretty normal. Two things you want to check are the condition of your radiator cap (have a shop pressure test it), and the condition of your coolant. If the coolant is pure water, or even worse, more than 2 years old, drain it and refill with a good 50'50 coolant/distilled water mix. Old coolant boils easily.

Boost the effectiveness of any coolant by adding some Red Line "Water Wetter" ro similar surfactant product.

As far as Engine Ice goes, it's a good product, but all it is is distilled water and propylene glycol coolant, so it's a bit overpriced, but it's convenient. It will not keep the engine any cooler, though. It has a higher boiling point than some ethylene glycol mixes, so it resists boil-over better, and some people mistake that for a cooler running bike.

But then, there's nothing wrong with it running hot as long as the temperature is controlled, and the coolant stays in the system.


Posted June 17, 2008 - 07:14 PM


I ride in Texas and the more cooling the better. the pump really does help with the coolant. the watter wetter does help also. we added that to a friends '02 CRF450 and boils over at start up literally. it kept it down for a lil bit. Those little FX temp stickers helped on mine i had regular coolant in there and stock pump cooled it down 15 degrees. like i said in my other previous reply. i know what your thinking moves coolant faster but doesnt absorb heat.

  • dmoney1074

Posted June 17, 2008 - 07:18 PM


No one has mentioned jetting... if your pilot circuit is too lean it will overheat idling in no time.

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