What's it mean when the crankcase is pressurized???


4 replies to this topic
  • drjon

Posted August 03, 2006 - 06:24 PM

#1

So on the new to me 2000 XR600R I just got a couple of days ago I noticed that the hose coming out of the crankcase is blowing air out at me. What the h*ll is that? Is it normal? Bike has a Wiseco 11.5:1 piston in it. Bike doensn't smoke out the tailpipe or anything and feels ok.

  • drjon

Posted August 04, 2006 - 03:53 AM

#2

Anyone??

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

Posted August 04, 2006 - 04:04 AM

#3

A certain amount of crankcase pressure (blowby) is normal. If there is a lot of pressure accompanied by oil vapor and oil dripping from the tube, that is excessive and indicates worn piston or rings that is allowing combustion pressure into the crankcase. It is a good idea to use a filter on the breather tube. I mount the filters high in the frame above the carburetor area, this prevents dust/dirt/crud and water from entering the crankcase.

  • SniperTeamBravo

Posted August 04, 2006 - 07:52 AM

#4

A certain amount of crankcase pressure (blowby) is normal. If there is a lot of pressure accompanied by oil vapor and oil dripping from the tube, that is excessive and indicates worn piston or rings that is allowing combustion pressure into the crankcase. It is a good idea to use a filter on the breather tube. I mount the filters high in the frame above the carburetor area, this prevents dust/dirt/crud and water from entering the crankcase.


Mine does it (both of them) and it is normal if there isn;t like you said, allot of oil or crud comming out. Mine blows wispy air out with the piston stroke, and is totally clean. But it happens whenever it is running. please tell me thats normnal.

  • cleonard

Posted August 05, 2006 - 02:15 PM

#5

Yes it's normal. Except for the breather the cases are sealed. When the piston goes up the crankcase volume increases by 600cc and it sucks in air. When the piston comes down, that 600cc of air is forced out. Any blow by increases what comes out. When the blow by gets to be too much, oil will get blown out the breather. Then it's time for some new rings.





Related Content

Forums
Photo
Washington

Cle Elum Sunday 5/29: Looking for dual sport tips by TigerTanker


Dirt Bike   Dirt Bike Regional Discussion   Northwest
  • Hot  32 replies
Forums
Photo

2015 XR650L Squeaking noise by Crayjay


Dirt Bike   Make / Model Specific   Honda   XR600/650
  • 3 replies
Forums
Photo

ignitech programmable XR650L CDI by brianhare


Dirt Bike   Make / Model Specific   Honda   XR600/650
  • Hot  60 replies
Forums
Photo

DirttyPig 2005 Xr650l Prroject! by braapmebb1moretime


Dirt Bike   Make / Model Specific   Honda   XR600/650
  • 22 replies
Forums
Photo

XR650L super moto wheels by greggkklee


Dirt Bike   Make / Model Specific   Honda   XR600/650
  • Hot  28 replies
 
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.