1st time on trails... bike overheated :(

15 replies to this topic
  • viggen

Posted July 23, 2005 - 04:20 PM


Today I took my 99 yz400f to some trails & it was very muddy & well....crappy.

I got stuck on a rut for a minute or so & gave the bike a bit of gas to get over the spot, it was a very slow area due to lots of standing water. Anyways, I pulled out of the sport & went down a small hill when LOTS of steam was coming from the engine so I turned it off. Fortunantly I was really close to the trailer & our day was about done anyways.

I guess my question is, is this normal? IT was pretty hot & I was moving slow due to the conditions

I definantly need to change the gearing for trail riding

  • DoctorRzed

Posted July 23, 2005 - 04:30 PM


I never heard of steam coming from the engine??? Change the antifreeze and use some engine ice coolant.

  • flintlock28

Posted July 23, 2005 - 04:57 PM


Are you sure it wasn't just water from the mud that splashed up and was boiling over??

  • viggen

Posted July 23, 2005 - 05:09 PM


definantly was coolant due to the smell :applause:

the engine/bike was covered in mud thus I couldn't tell exactly where the steam was coming from

I chekced over the bike after cleaning it & everything looks fine. Hopefully go to the track this week & see how it runs

  • BeauGt

Posted July 23, 2005 - 05:43 PM


I've had my 426 boil over like that, just put more antifreez in it and was all good

  • viggen

Posted July 23, 2005 - 05:51 PM


thanks for the info everyone :applause:

I just talked to the prev owner & he also said it's normal for the situation I was in, they do not like to rev when stopped

Looks like I need to carry a thing of antifreez with me everytiime I go just to be safe

  • grayracer513

Posted July 23, 2005 - 06:38 PM


Looks like I need to carry a thing of antifreez with me everytiime I go just to be safe

Do NOT open up a hot cooling system without gloves, googles, and EXTREME CAUTION. Coolant at that temperature and under that kind of pressure can take the skin right off of you almost instantly (but far from painlessly). If it doesn't, you might wish it had.

It needed to be said.

  • viggen

Posted July 23, 2005 - 08:32 PM


very true, some people do not know that & fortunantly I do

I meant keep some coolant at the trailer & add it AFTER it's cooled down :applause:

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  • MisterMan

Posted July 23, 2005 - 08:58 PM


search for the "turkey baster mod" or the "coolent puke tank" or something along the lines of...it was 104f today and I was heat'n it up /w/ stock gearing and mine did just fine.

  • 99raptor

Posted July 24, 2005 - 04:40 AM


400/426/450 don't like to idle for a long time [more than 2 min],so creeping in 1st gear is just as bad.they'll puke coolant without some decent air flow thru the radiators.my experiences anyway.

  • ride yzf all the way

Posted July 24, 2005 - 05:51 PM


it was just water hitting the pipe and motor mine does it all the time

  • viggen

Posted July 24, 2005 - 07:18 PM


I took the bike to the track today for a while & zero overheating problems.

I added water to the radiator that overflowed before I went out & all is well

DAM are these things FUN!!!

  • ncmountainman

Posted July 24, 2005 - 07:20 PM


evans npg-r :applause:

  • Lukejt

Posted July 25, 2005 - 01:34 PM


For trail riding, a larger rear sprocket and a flywheel weight will make huge difference.


  • CRFThumper

Posted July 25, 2005 - 01:37 PM


evans npg-r :eek:

YEA.....what he said!!! :applause:

  • viggen

Posted July 25, 2005 - 03:25 PM


what is evans npg-r?

I was thinking about changing the sproket, I think people say use a 51 tooth?

are weights all I need? Something else I wanted to do!

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