426 spewing oil

9 replies to this topic
  • Fly_426

Posted June 25, 2004 - 04:44 PM


I noticed a while ago when riding my bike it continuously drips oil out of the breather hose that runs down the left hand side of the frame. After every trip to the dunes I have to put in a quart to a quart and a half of oil. Today I also noticed as I was straddled on a razorback it actually blows air out that hose. Is this normal?

  • 426F

Posted June 25, 2004 - 05:02 PM


I believe that it is somewhat normal for the breather to drip a minimal amount of oil but not a quart per day. The only thing that I can think of would be possible piston blow by pushing oil out of the breather. When was the last time you replaced the piston and/or rings?

  • chrome-crf

Posted June 25, 2004 - 05:03 PM


Wow :thumbsup: if you are losing a quart to a quart and a half, that is all your oil. You should definitely not be losing that much oil unless one of your breathers is clogged up.

  • YZFan

Posted June 25, 2004 - 05:08 PM


Is it overfull to begin with???? You have to check the oil with the engine warm and dont screw the dipstick down just rest it on the top.

  • sirthumpalot

Posted June 25, 2004 - 05:55 PM


I'm with YZFan, are you sure you're not over filling? If you're loosing a quart then something is very wrong. When you check your oil, be sure that you run the motor BEFORE you check the oil! It's a dry sump engine and when it sits, the oil runs out of the tank and into the sump.

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  • JYD

Posted June 25, 2004 - 06:37 PM


the whole thing bone dry only holds 1.7 quarts of oil. if you over fill it, it will spew. also, if the breather hose from the crankcase is clogged or pinched, it will also spew.

  • Fly_426

Posted June 25, 2004 - 07:18 PM


I have not been checking it after warming it up. I guess I wasn't aware of that. Hopefully that is the problem. The piston and rings have never been done, that will come this winter. But for now I will try warming it up before checking it. Any comments on the air blowing out of the same breather hose. Just wondering if that is expected and I've just never noticed it till now. Thanks for the info, you guys are clever!!!

  • yathump

Posted June 26, 2004 - 01:11 AM


The air coming out is normal, a guy i know just picked up a 426 and called me asking how much oil these things need, said he got 4qts :thumbsup: out of his bike so i think the previous owner was doing the same thing when checking the oil level.

  • YZFan

Posted June 26, 2004 - 01:13 AM


The air is normail the oil isnt. That air is crankcase pressure and it is very normal. The oil is held in the frame but when the bike sit's all the oil drains back into the engine untill you start it again. That is why the engine has to be warm when you check the oil. If you check it after it has been sitting it will always show low and then when you fill it then it will be over full and pump oil out of the crankcase vent tube. Hope this helps.

  • oldNslo

Posted June 26, 2004 - 06:01 AM


No doubt it's overfilled. Since no one knows what I look like I can admit without fear of public humiliation and embarrassment I too made the mistake of over-filling. I knew to check it warm but I had a Bud-Lite moment, and checked-filled fluids when getting ready for a weekend ride. Oil all over the place until the level settled down. No harm should be done...that's the reason for the overflow :thumbsup:

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