Spark plug cover with engine oil... rings ?

2 replies to this topic
  • steevefortin

Posted May 17, 2008 - 07:51 PM


Hi! Here is my first post on this site.I found a lot of good info before but nothing on my present issue. So here it is, I have a YZ450F 2007 and I just changed the water pump oil seal and the fuel screw. I put a Zip-ty fuel screw also the JD jetting kit for my model. After everything was done, i did start up my bike. It did start on the first kick. After few minute to let it warm up, while ajusting the fuel screw I was bliping the gas to find to good spot of the fuel screw and here start my problem...

On blip, a blue smoke was going out of the pipe. First time ever it heppened. So I decide to go run the bike a little hoping it will correct it, but after few minutes again, back at my place, the blue smoke was worst. It was smoking all the time, so I kill the engine. I look my spark plug and it was cover with engine oil, still wet. Anyone have any idea, maybe the rings ? what I should look for ?

Thanks for any help, it will be appreciate.

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  • cheeseryzf

Posted May 17, 2008 - 08:48 PM


do a compression test. hook the gauge up to the spark plug hole and kick it 5-6 time at WOT. if you have a manual it will tell you what pressure you ar looking for. probably like 130-150 psi. if its low then put a little oil down in the plug hole and do the test again. if the reading comes up to near normal then your rings are worn out. if the reading was normal after the first test, then the oil may be coming from the valve seals. no real way to test them. when you take the head off, or at least take the header off, look to see if the exhaust valve is covered in carbon, then thats you indicator. good luck

  • steevefortin

Posted May 17, 2008 - 09:49 PM


Thanks for the answer, I should have wrote here before starting working my way to the piston :thumbsup: I have the camshaft cover out and I will work on the camshaft and the rest tomorow. I'll definetly check the exaust valve.

I never went to check the rings before, what should I look to to know if the rings are good or not ? The book call to measure the side slack of the rings, is that it ?

I was reading about the valve seal in the book, and it seems a big job... any advise ?

Thanks again

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