New 1999 YZ400F PROBLEMS


14 replies to this topic
  • bhsballer76

Posted October 28, 2007 - 05:36 PM

#1

I just bought this 1999 yz400f six days ago and i had it out this saturday for the first time. I paid 1500 for it and it is my first four stroke and i have previoulsy had a 1990 cr125 and 1995 yz125. I was really excited to get this bike but i am now a bit worried. There seems to be something coming out of the compression release tube. I included pictures so hope i hope you guys can help me out here. This is the amount that came out after about 24 hours since i got it home from riding saturday night. I noticed before i had it out that it would leave a few drops a day but i didnt know what it was or if it was a problem. Now i am a bit concerned. I included some other pics so let me know what think. Thanks

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  • C333

Posted October 28, 2007 - 05:40 PM

#2

Looks almost like frothy oil to me?:worthy: Mine does that when I put too much oil in it.

  • bhsballer76

Posted October 28, 2007 - 05:48 PM

#3

Looks almost like frothy oil to me?:worthy: Mine does that when I put too much oil in it.



so is it something to be concerned about? DO you have the same year bike?

  • yzfrider67

Posted October 28, 2007 - 05:52 PM

#4

it looks alot like water mixed withoil to me. it seems awfully thick though. i would drain the oil just in case.

  • XHMXR

Posted October 28, 2007 - 05:58 PM

#5

it looks alot like water mixed withoil to me. it seems awfully thick though. i would drain the oil just in case.


Im with you. Looks like oil in an oil pan after a head gasket leak. Combination of oil, anti-freeze and water. I hope not.

  • C333

Posted October 28, 2007 - 06:35 PM

#6

so is it something to be concerned about? DO you have the same year bike?


Ya I have a 99 400f but I would follow the advice above and change the oil to be sure. Being that the bike is used you really don't have a great idea about how well in was maintained until you do it yourself for a few times. I've had the same exact kind of goo come out before, out of the same place but, it hard to tell from the picture, but your goo looks a bit thicker. Mine was a simple matter of too much oil.

Change the oil and filter, run it for a good ride and see what's what IMO.

  • hillclimbguy

Posted October 28, 2007 - 07:27 PM

#7

Change the oil and filter. Check the coolant, make sure thier is no oil mixxed with the coolant. You may have a leaky head gasket. That does not look good what is coming out your bike.
Did you submerge your bike in water? You may want to check your vent hose for the crank case.

  • bhsballer76

Posted October 29, 2007 - 06:14 AM

#8

any other suggestions, Im going to check the coolant and oil soon to see if nything looks wrong with it.

  • grayracer513

Posted October 29, 2007 - 08:27 AM

#9

It's critical that you check the oil before riding it again at all. Glycol based coolants destroy the ability of engine oil to lubricate anything. If the oil looks bad, that is, milky like it has water or antifreeze mixed in, drain it, replace the filter and go get a gallon of Rotella non-synthetic at Wal-mart. Use only one quart of oil. Be sure it has coolant in the radiator.

Take the bike somewhere where you can ride it for a while, and take a couple of gallon bottles and a pan with you to collect the oil with. Run the bike for 20 minutes, riding it fairly easy. Once it's good and warm, drain the oil from the frame and the crankcases, and refill it with 1.5 quarts. Run it for half an hour and repeat this process, using the remaining 1.5 quarts. Run it for an hour or so, checking the oil periodically to see it it's staying clean and not getting milky again. If it's OK, take it home and change to whatever oil you choose to use.

If the oil won't stay free of the milky stuff, check the coolant (NOT while it's hot) to see if the level has dropped more than an inch or so. If you have significant coolant loss along with new water in the oil (or oil in the water), you have a head or base gasket problem.

  • bhsballer76

Posted October 29, 2007 - 08:32 AM

#10

thanks for the help. How hard is it to change a head gasket?

  • grayracer513

Posted October 29, 2007 - 08:39 AM

#11

It's not difficult, but it's a lot more complicated and time consuming than with a 2-stroke.

  • Ga450owner

Posted October 29, 2007 - 10:46 AM

#12

This is water in the oil. I would bet that the bikes breather tube was submerged in a water puddle and suxed up a lot of water. Never start these while in a creek or deep puddle as the bike will sux up whatever that breather tube is in.....also you need to either reroute the breather tube or add the other clamp to it.
If it were me....unfortunately I have gone through this already on a older WR.....empty all of the oil goo out, add new oil, and add marvels Mystery oil to it run it for 20min....redrain. Replace oil and filter more Marvels Mystery oil go another 1hrs worth of riding and check again for any white in oil....ids there dirt in the oil filter?

For kicks and giggles....did the water in the radiators suddenly dissappear or level go down? This would indicate blown head gasket...or a bad H2O pump seal

  • scalejockey

Posted October 29, 2007 - 07:12 PM

#13

ditto on the water low in the radiators.. bad water pump seal??

  • bhsballer76

Posted October 31, 2007 - 08:35 AM

#14

what should oil look like after a about an hour and a half ride. I changed the oil and took the bike out yesterday and it ran fine.When i brought it home and noticed a while later another little pile of the creamy looking stuff. So im going to change the oil again. What should it look like if it is good?

  • grayracer513

Posted October 31, 2007 - 09:19 AM

#15

It should look almost like it did when you poured it in. Don't judge it until you drain the third oil fill out, using the process I recommended. If it still looks bad then, you have a problem.





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