bubbling in radiator?

5 replies to this topic
  • Andyyzf426

Posted February 16, 2008 - 03:22 AM


Hi i have a 2000 426 all standard and when i run the engine weather it's riding the bike or just starting it in garage, the moment i hit the kill switch u can here the rad bubbling????
Would anybody agree it might be head gasket?:applause:

  • SRT426

Posted February 16, 2008 - 03:48 AM


The bubbling sound is because the bike is running hot and the coolant is boiling. Check coolant level first as it may be low, and if it is top it off and closely monitor to see if your losing coolant. Then check you rad cap as it may be loosing pressure causing the coolant to overheat, boil and spew out the radiator. Not sure of the PSI but some people switch caps to aid in cooling and boil over performance. Also, what coolant and ratio mix are you running. Your coolant could be dead and time to replace it?

  • Andyyzf426

Posted February 16, 2008 - 04:17 AM


i'm using all weather coolant from my local spares shop.
the only thing i dont get is it bubbles even if i start it for 10 sec then shut it off, giving it no time to warm up or for the coolent to even raise in temp??

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • SRT426

Posted February 16, 2008 - 04:32 AM


Bad water pump? Air in system?

  • spc mike

Posted February 16, 2008 - 01:03 PM


the bubbling is normal if you ask me. me as well as my buddy both have 2002 426's and they do exactly what you are describing.:applause:

  • freerideyz250

Posted February 17, 2008 - 06:47 AM


My 2008 does it as well. Usually only when it is warm, but you shut it off, and you can still hear the coolant moving around. Never loses any coolant, never over heats. I think its just part of the way these cooling systems are set up.

Related Content


yz250x vs 450 4t comparisons (preferably desert riding) needed by JakeNorthrupYZ450F

Dirt Bike   Make / Model Specific   Yamaha   Yamaha 2-Stroke
  • 9 replies

2016 YZ450 by CaptainKnobby

Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  59 replies
WR Camshaft Swap Info - last post by jamesm113

WR Camshaft Swap Info

  • 0 replies

Is the 2016 GYTR Yamaha YZ450F too fast? by Fryboy

Dirt Bike   Special Interest Forums   Pro Racing
  • * - - - -
  • Hot  241 replies

100 hrs on 2014 yz450f, shim valves or replace them? by ttr230rider6

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • Hot  79 replies

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.