my wr leaks coolent when it gets hot...

10 replies to this topic
  • yamahahahaha

Posted November 17, 2003 - 09:32 PM


when my bike heats up it tends to drip coolent out the black drain tube. :) As you may have guessed, I am not exactly a to ride, but don't know my @ss from my elbo when it comes to working on my bike. Has anybody run into a similar situation? any suggestions?



  • yamahasocal450

Posted November 17, 2003 - 09:44 PM


welcome to tt :D, isnt the coolant overflow supposed to catch it, even if thats over flowing it should come out the clear tube, unless its all dirty, its common for a 4xx to over heat when no air is flowing over the radiatiors or going on very tight trails, i myself havent had any overheating problems but i would shut the bike off at all stops to let it cool down :)

  • yamahahahaha

Posted November 17, 2003 - 09:53 PM


Hmmm...I'll check for blockages in the clear tube that may be preventing the coolent from getting to the overflow. :)



  • ETP

Posted November 18, 2003 - 06:26 AM


If you idle these bikes for several minutes while working on them, they will start to boil over, which is normal I learned, but the overflow should catch it as Danny has said.

  • WR_Jason

Posted November 18, 2003 - 08:13 AM


If they get too hot you can fill the overflow and it will push out. My 400 can idel for about 5 mins when hot before she starts to push out into the bottle, about 5 mins more and it will start pushing out. If it starts to push out after less than 5 minutes check for lean jetting, there should be some popiing and sputtering in that case then too.

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  • yamahahahaha

Posted November 18, 2003 - 06:05 PM


I will try all of your suggestions this weekend...thanks so much for all your helpfull advice and info...



  • pedman

Posted November 18, 2003 - 09:54 PM


I have noticed that I leak oil from the black tube. I understand that this is a over flow for oil? It ususally happens if i put too much oil in.

  • dave450wr

Posted November 19, 2003 - 02:34 AM


My 450 over heats real quick on tight trails.I hear it start to bubble , but i have never seen any coolant com out.It should go into the overflw tank.My 426 didn't over heat once.I have run my oil tube to the air box as it used to suck water into the motor when crossing creeks.

  • R_Little

Posted November 19, 2003 - 01:25 PM



The "black tube" is the crankcase breather and it will will drip oil from time to time, especially if you run at high speeds or overfill the oil.

The Coolant will run out the clear tube into a catch tank which should be under the rear numberplate.

This is all normal.

Are you leaking oil out the black tube?

  • BEAN329

Posted November 19, 2003 - 05:02 PM


you might want to check the clearance between the header pipe and the water pump housing. mine gets very close after dropping it a few times on the right hand side.

  • Balcs

Posted November 19, 2003 - 09:32 PM


I had a chance to go to the US Open at the MGM in Vegas this year and after the race I went to an after party that Engine Ice was putting on at the ESPN Zone. I had a great opportunity to discuss Engine Ice with them and it really helps keeps your temperatures down. I would say look them up on the net or go to your dealer and get some if you are having some problems and then go from there.


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