03 wr450 Coolant issues

7 replies to this topic
  • RaphFoFiddy

Posted August 01, 2006 - 08:57 AM


Alright I've had this bike from day one and I've always been a little sketched out when my bike spews coolant out of the hoses. This only seems to happen if I'm riding very slowly (stop and go) through typical NE technical tight stuff. yesterday I was out (bout 95-100F) and we were working through a swampy area so alot of stopping and slow going. The last time I stopped not only did the coolant flow out the overflow tubes but at the same time it flowed back into resivoir and appeared as if it were boiling there.
I know I can add more coolant but I'm not cool with pissing even the most trivial amount of coolant in the middle of the woods (not that it's that much but I have a hippy freeloading it on the couch of my conscience)

Is this typical and I'm being paranoid, or am I looking at the symptoms of something that could be a larger issue down the road?
I hear alot of overheating is caused from low coolant pressure or jetting that is too lean. been thinking of getting a jetting kit from TT as well, I'm heading out to Hatfield McCoy in a few weeks so I'm a little sketched of playing with my jetting so close to a big trip.

  • Turismo

Posted August 01, 2006 - 04:10 PM


It sounds normal to me, that is why you have a coolant reservoir!
You just have to stop more often in that sort of terrain.
(No doubt everyone will try to tell you that you are lean :thumbsup: )

You could go to a different coolant like evan's NPG-R or Engine Ice.
I run Engine Ice and found it to be an improvement, but I can still boil it in the very sloppy going, or real slow tight stuff. A radiator fan would be the way to go, If only someone made a kit for them!

  • RaphFoFiddy

Posted August 02, 2006 - 06:44 AM


I have put in a considerable amount of water wetter (an additive that is supposed to yeild similar results as the engine ice) yet, no dice...
when I bought it the dealer told me it would do it during the break in cycle, it just never stopped. How I usually ride it doesn't care, this bike likes to move I guess it doesn't like to be limited to 2nd gear.

  • Turismo

Posted August 02, 2006 - 07:12 AM


this bike likes to move I guess it doesn't like to be limited to 2nd gear.

No they don't, they run hot.

Have you played around with your jetting yet?

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  • StreetbikePimp

Posted August 02, 2006 - 09:23 AM


Proper jetting will help this problem, but if you still stoping on the trail after 2nd gear riding and letting it idle for more then 30 seconds or so, it's going to start boiling.

  • mtrablue

Posted August 02, 2006 - 11:38 AM


don't use more water wetter than is recommended. it's less effective when you use too much. it will not lower the engine temp but will help with some of the boiling. that said, any bike would boil in the conditions you were in. any 4strk ktms with you. orange tea kettles. i am told that both the crfx hondas and the ktm's have a fan as an available accessory. one way or another, it's scary to smell steam when your on your bike.

  • RaphFoFiddy

Posted August 03, 2006 - 09:29 AM


I haven't had it jetted since 04, not exactly how often your supposed to fiddle with it. I haven't found a shop that I trust yet so I'm eventually going to have to suck it up and learn how to jet it myself. I heard the JD or Zip Ty needles are supposed to make it easier and be a vast improvement over stock. I probably did add too much water wetter... OK a few more questions:
1) how often do you guys preform a coolant flush?
2) Boysen water pump/impeller, worth a shot as alternative to fans?
3) Anyone switch over to the GYRT silencer on the stock pipe? I hear a almost diesel like clacking sound while idling with the cork in and my experience with one lungers is pretty weak, anyone confirm that as normal/healthy?

You'll have to forgive me for being such a noob It's my fist bike and I don't know anyone in my area with one so I'm kinda on my own as to scheduled and preventative maint. I've done some simple/free mods the breather tube relocation to the airbox, slight airbox modification, snipped the fuel screw. Factory Connection Suspension (I weigh 230-250 and WOW what a difference) and some other cosmetic/protective measures.

thanks for all your input so far

  • gregwr450f

Posted August 03, 2006 - 12:49 PM


put two layers of heat tape on the bottom of your right hand side rad, the header pipe glows red and tranfers alot of heat into the radiator, the tape made a big difference to mine.


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