overheating


2 replies to this topic
  • stephen957

Posted May 24, 2004 - 02:37 PM

#1

Okay son's new bike 2004 yz450f great bike question if exhaust pipe has turned a blue color is that a sign of over heating my younger son has a 2003 yz250f and the pipe is a more amber color older boy is complaining that the pipe feels hot against his leg at the starting line he races mx yes I checked for fuilds and every thing is topped up I know it sounds like a newbie question but I have watched this site for a couple years first time writing in great site just want to be sure I ride a CFR 450 and I have to say impressed with the Yamaha just wondering if maybe the bike is a little lean bike starts good with choke first time but if left for a couple hours it seems to start better with choke on .

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

Posted May 24, 2004 - 02:39 PM

#2

Needing the choke when the motor is cold is normal, that's why it's there. 4-stroke headers get very very hot, that's normal too. Make sure it has a good heat shield. If you want to see how hot it gets, start it at night (in the dark) some time and let it idle for a minute.

  • grayracer513

Posted May 24, 2004 - 03:46 PM

#3

The stock '04 YZ 450 exhaust is all titanium, tip to tip, except for the muffler can. Titanium turns all kinds of cool colors when heated. The FMF Ti4 on my '03 turns deep blue clear to the muffler after a hot day's ride in big dunes. Normal. Four stroke exhaust temps are much higher than two-sters, and you really can't make a good comparison to another bike, even the same kind, unless the pipes are the same.

Because a four stroke head is so completely filled with valves, there isn't a lot of direct contact between the combustion chamber and the engine coolant. As a result, a lot more heat is still present when the exhaust cycle comes around. They also are not able to idle at a standstill for as long as the oil burners for the same reason.

As long as it's not barfing coolant all the time, it's probably OK.





Related Content

Forums
Photo

Megabomb Fitment by 288yz450


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 1 reply
Forums
Photo
Supercross

Wilson the Blue Privateer by jetfuel


Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  50 replies
Forums
Photo

YZ450FX OR YZ450F by MESSMAKER


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • Hot  30 replies
Forums
Photo

Is it worth it? (Cam and High compression piston) by macgi77


Dirt Bike   Make / Model Specific   Honda   CRF 150/230 F/L
  • Hot  36 replies
Reviews

Yamaha YZ450F 2017 by Chris.GVS


Yamaha YZ450F 2017
  • * * * * *
  • 1 review
  • Last review by Tommyk_55
  • On January 15, 2017
 
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.

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.