Jump to content

  • Follow us:

  • Facebook
  • YouTube
  • Twitter
  • Google+
  • RSS Feed
  • Google+





Related Reviews

Honda CRF450R 2014


Last review by MotoXkid
* * * * -

Honda CRF450R 2005


Last review by pfhenry
* * * * -

Honda CRF450R 2007


Last review by Jnrb89
* * * * -

Honda CRF450R 2008


Last review by doopilot
* * * * -

Honda CRF450R 2006


Last review by Shonutts
* * * * -



Related Garage

043001crf450rtop.JPG

Honda CRF450R (2002)


Owner: fooled4throttle
Added on October 16, 2014
Photo
- - - - -

CRF450R Overheating?


  • Please sign in to reply

21 replies to this topic
  • MMH

    TT Bronze Member

321 posts
Location: Virginia

Posted July 31, 2007 - 02:33 AM


How do I know? If I let it idle for more than a couple of minutes it starts pushing coolant down the tube. I'm worried that when on slower trails I will run low on coolant, overheat the engine & not know it. So how do I know when the CRF is too hot?

Also, Will an exansion tank from a 250X or 450X help?

  • CarpeDiem

    TT Member

50 posts
Location: Michigan

Posted July 31, 2007 - 03:56 AM


Replace OEM cooliant with Engine Ice ;-)

  • DS31273

    TT Member

44 posts
Location: Iowa

Posted July 31, 2007 - 04:24 AM


I also have the same problem trail riding spitting coolant i do run engine ice which helps some but, i took a plastic turkey baster & extended my over flow hose and mounted it! this helps with the loss of coolant!

  • c_bach_115

    TT Member

27 posts
Location: Kentucky

Posted July 31, 2007 - 05:45 AM


Depending on how your skid plates mounts you can use the overflow tank from a 450x. I have an 05 CRF-450R and I was able to use the overflow tank from a 450x. With the tank installed, I was only able to use 3 of the 4 mounting brackets for my skid plate. I safety wired the one where I couldn't use a bracket(it was the front left corner). I have ran several hare scramble races and haven't had an issie with losing all my coolant since I installed the tank. Just letting you know that you can use the tank from a 450X as long as you can still mount your skid plate.

  • MMH

    TT Bronze Member

321 posts
Location: Virginia

Posted August 01, 2007 - 02:22 AM


OK - sounds like an expansion tank & Engine Ice will help.

How do I know when the engine overheating - I don't want to damage it!

  • Masterlink52

    TT Member

49 posts
Location: Oklahoma

Posted August 01, 2007 - 10:23 AM


There are various trick or gimmicks to try and stop the coolant from escaping and some of these may be affective [COLOR="Red"]but the facts are the CRF450R is not designed to be a trail or tight terrain bike or designed to run at slower speeds, they are race machines therefore require consistent air flow thru the radiators.[/COLOR]

I agree “Engine Ice” coolant helps but if the radiators do not maintain a consistent air flow passing through them it doesn’t matter what type of coolant used the motor gets hot and the radiators will percolate coolant out the overflow hose depleting coolant level and if not monitored will overheat the engine. [COLOR="Blue"]I’ve personally have never overheated a bike engine, but if you do be certain the engine will quickly let you know in one way or the other and it could result in major $.[/COLOR]:eek:

It's no secret that the CRF450X is designed for off road trails etc and comes with electric start, front/rear lights and the benefit of a radiator overflow reservoir to eliminate loss of radiator fluid and over heating. :thumbsup:

  • nexrace

    TT Silver Member

716 posts
Location: California

Posted August 01, 2007 - 02:17 PM


Dude do a search on "turkey baster". It is a great overflow device. People have also on the early bikes made overflows out of their frame spars. You can do a search on this for some helpful info. If all this back yard tech is no good for you check out motion pro for an overflow. Another good idea is the 250x over with a couple of tabs added to your sub frame.

  • crf-f crf-r trx cbr

    Get Help Now

8,761 posts
Location: Ohio

Posted August 01, 2007 - 03:29 PM


fluidyne

  • sonobob
15,983 posts
Location: Georgia

Posted August 01, 2007 - 03:43 PM


My '06 would puke coolant in the slow stuff until I made two small changes...I keep the coolant level filled to the tops of the fins inside the radiator, and I added a few ounces of the Redline Water Wetter. It not only keeps the engine temps down but also lubricates the water pump seals and helps prevent rust/corrosion in the system. :thumbsup:

  • flyingbryan

    TT Newbie

4 posts
Location: California

Posted August 04, 2007 - 03:33 AM


I have the same problem with overheating and I tried the Fluidyne radiators on my 02 CRF450R. With the new radiators on I had to take off the Devol radiator guards (not good). No luck at all with the Fluidyne's, but I think I have other problems because I can only ride for about 20 minutes before all the fluid is gone out the overflow line. I put a water bottle on the overflow to confirm that is where the fluid is going. The first year or two I had this bike I never had this problem with overheating. Anyone have any idea's? Maybe the water pump?

  • Desert Rat 450

    Get Help Now

6,356 posts
Location: California

Posted August 04, 2007 - 06:00 AM


I also have ran hot from time to time. Like these guy's I run Engine Ice,Devol Radiator guards and i also installed a Boyesen Hi Flow kit, I haven't had any issues since. http://shop.thumpert...fault.asp?p=406

  • oldshooltoy

    TT Member

59 posts
Location: California

Posted August 04, 2007 - 08:31 AM


I have the same problem with overheating and I tried the Fluidyne radiators on my 02 CRF450R. With the new radiators on I had to take off the Devol radiator guards (not good). No luck at all with the Fluidyne's, but I think I have other problems because I can only ride for about 20 minutes before all the fluid is gone out the overflow line. I put a water bottle on the overflow to confirm that is where the fluid is going. The first year or two I had this bike I never had this problem with overheating. Anyone have any idea's? Maybe the water pump?

blown head gasket? do a block test

  • thrillbillie56

    TT Bronze Member

248 posts
Location: Florida

Posted August 04, 2007 - 09:51 AM


I have the same problem with overheating and I tried the Fluidyne radiators on my 02 CRF450R. With the new radiators on I had to take off the Devol radiator guards (not good). No luck at all with the Fluidyne's, but I think I have other problems because I can only ride for about 20 minutes before all the fluid is gone out the overflow line. I put a water bottle on the overflow to confirm that is where the fluid is going. The first year or two I had this bike I never had this problem with overheating. Anyone have any idea's? Maybe the water pump?


I had that problem(although not quite that severe) and it turned out to be that my radiator cap was bad, so i replaced it with a higher pressure one, and it has worked fine ever since. Or if that doesn't work it could be the water pump, pull it apart and check the seals/impeller. And if that is not the problem, check the head gasket, it is possible due to the age(if its never been replaced) of the bike that the old one is trashed...you can do this by doing a compession test, or pulling the head if you feel the need to do so(good time to check the valves too):thumbsup:

  • flyingbryan

    TT Newbie

4 posts
Location: California

Posted August 08, 2007 - 11:18 PM


Thanks for all the help on my 02 450 overheating problems. I will have some time off work next week to try to get the problem fixed. I will let you know how it goes.
Thanks again,
Bryan

  • maxchris

    TT Newbie

4 posts
Location: California

Posted August 13, 2007 - 08:54 AM


I had the same problem, read somewhere it coud be valve to tight so i got it check and it was, after ajustment no problem. Max

  • flyingbryan

    TT Newbie

4 posts
Location: California

Posted August 14, 2007 - 03:22 PM


Thanks for all the help on my 02 450 overheating problems. I will have some time off work next week to try to get the problem fixed. I will let you know how it goes.
Thanks again,
Bryan


I went riding this weekend and found the problem with the overheating. It was the Fluidyne Radiator. When putting on the cap one time it was a little hard to get on so I started looking at the area around the cap and saw the overflow nipple had the threads in just far enough to interfere with the cap. I took out the nipple cut the threads back, put it back in and the overheating problem was gone. I also put in the Boyesen Hy-flow water pump over the weekend along with new Engine Ice coolant. With all this I could not get the bike to over heat on trails, or hill climbs in 100 degrees F weather. What a difference a day makes. I also had a home made overflow bottle on to see if, and when any fluid was coming out. There was the smallest amount that would come out and get sucked back in after moving again but I don't think it is necessary to have the overflow bottle.

One note for anyone with the overheating problems. The time you get the fluid coming out the overflow is after you have been on the gas and you go to idle, and if you stay at idle sitting still.

I was riding with some newer guys on trails (slow), stop and go, and at idle after hard riding, and keeping it at idle for 5 minute or more before going and never had it overheat after the fix.

Thanks to everyone with the help, now I can get back out there and ride.
Bryan

  • Just thinkin

    TT Member

52 posts
Location: Indiana

Posted August 14, 2007 - 05:47 PM


This is going to take a bit but read on.
There is a difference between overheating & spiting water out of the overflow.
A cooling system requires PRESSURE to raise the boiling point of water, which happens to transfer heat better than any other coolant, all the "snake oil" included. The pressure is created when the fluid heats up & expands. Since water, or any other fluid expands when heated, the expansion in the enclosed space creates pressure in this enclosed space. This pressure raises the boiling point of the coolant and is an absolute necessity. Try filling a can to the top with water, closing the top, & putting it on your kitchen stove. It BLOWES UP as the fluid expands with no place to go !
The radiator cap is a crude pressure relief valve that prevents over pressurization by dumping the excessive pressure. Unfortunately, a rad cap does not regulate the pressure, it DUMPS it ALL! As soon as your cap dumps water, because of the natural expansion of the coolant, you have eliminated your means of producing the needed pressure. The coolant has already expanded so it has lost its ability to re-create the needed (expansion) pressure! What has happened is you have lost the pressure and along with it the ability to regain this needed pressure/boiling point! It's all downhill from here.
The key is to never allow the expanding coolant to open the cap ! You accomplish this by maintaining an "air spring" (air compresses & fluid doesn't) between the level of the coolant when hot & the radiator cap. This means letting the system find it's natural level by a one time overfill, then reducing the "cold level" of the coolant slightly below that level. Do not fill between rides because the level has been reduce to the top of the radiator tubes when cold ! Be assured, when up to operating temp the system will be full!

There are coolants that have a higher boiling point than water. However, they give a false sense of security because the don't "spit out" the overflow tube". Expansion, and the ability to transfer heat, are two totally different things. Use distilled water, water pump lube, and the highest rated pressure cap (1.9) you can get your hands on. Don't overfill your system & your bike will be happy. Don't forget to use anti-freeze during the winter when cooling isn't a problem.

  • mja

    TT Newbie

1 posts
Location: Michigan

Posted August 22, 2007 - 03:02 AM


I have a 2002 450 and got a 1.6 outlaw cap from pit posse on ebay so far have'nt lost a drop!!!!

  • nexrace

    TT Silver Member

716 posts
Location: California

Posted March 31, 2009 - 07:43 AM


I know this is a way old thread but for some reason I got caught reading it....
In the past I sourced a rad cap from a ford escort which is high pressure & waay cheaper in price than what is currently available for dirtbikes. Try napa with your spec on the diameter of the tabs on the rad cap & save some money...dan

  • ProMed

    TT Platinum Member

1,702 posts
Location: North Carolina

Posted March 31, 2009 - 09:58 AM


This one that I have was only $19.95.

http://www.pitposse....rahipr16ra.html


http://us.st12.yimg....e_2044_97067992





Related Content

Forums
Photo

2014 outdoor motocross predictions by ImAHondaMan


Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  67 replies
Reviews

Honda CRF450R 2015 by Bryan Bosch


Honda CRF450R 2015
  • * * * * *
  • 1 review
  • Last review by Hillguitar
  • On October 09, 2014
Forums
Photo

TRAIL READY 13 CRF 450R? by ShazzaM


Dirt Bike   Make / Model Specific   Honda   CRF450R
  • Hot  26 replies
Forums
Photo

Please help , this is my first post. Carb issues? by cjr19543


Dirt Bike   Dirt Bike Technical Forums   Intake - Jetting / Fuel Injection
  • 2 replies
Forums
Photo

2007 crf450 stuck in gear by Jackthomas1989


Dirt Bike   Make / Model Specific   Honda   CRF450R
  • Hot  30 replies

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users

 
x

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.

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