Major Oil Problems with yz426f

5 replies to this topic
  • WomackGarage

Posted July 10, 2008 - 05:07 PM


Well Ive owned this 01 yz426f for over a year now I check the oil every time I ride change it every couple rides and never had a problem till now.
So to get down to it, the oil capacity on these things is about 1.8 quarts I put in 2 quarts letting in run for 3 minutes. (the radiator is almost to hot to touch) and I check the oil dipstick, it doesn't register, so I dump in a 1/4 quart and still doesn't register. :thumbsup: I am baffled so I break loose the bolt in the front of the frame just under the exhaust let it run for a minute or so and no oil seeps out... I'm wondering if the oil pump is shot but if it was shot then why isn't the dipstick registering or maybe its just something simple I'm looking over. Maybe the oil is going somewhere it shouldnt?.... I don't know what to do now. Has Any had this problem!? HELP Please!

  • BBrown626

Posted July 10, 2008 - 05:52 PM


If you are following the procedure in the manual and it doesn't register then it sounds like you have a pump problem or blocked screen. Have you checked for pressure to the valves? Not familiar with that specific bike, but my Yami's have a bolt in the oil line up by the valve. We crack that and check for leakage to confirm pressure. You could similarly loosen one of the banjo bolts on the external oil line (behind the kick starter) to see if it leaks there.

  • grayracer513

Posted July 10, 2008 - 06:16 PM


Remove the sump drain plug and see what happens. It sounds like the return pump has failed, probably due to a sheared drive pin. The oil is being pumped to the engine, but not back to the tank (frame).

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  • WomackGarage

Posted July 19, 2008 - 02:56 PM


The oil screen wasnt clogged up but I reached up into the frame with a dentist looking tool and just above where it screws into the frame was packed full of this rag fiber crap Im assuming was from the fresh rebuild. (showing up 2 oil changes later? strange) The oil filter was also pretty clogged with metal flake and rag fibers, and the oil has to much metal flake for my approval to want to ride any more. But against my better judgement I changed the oil and filter cleaned the frame completely and it is still having the same symtoms. I know something went A-wall in the case now. Im just scratching my head and I wondering if its something I can do myself. I have a mechanic, thats possibly the coolest guy on the this planet earth, who does all my work for free but he has a few sponsered racers that need constant maintenance on their bikes and it takes a long time to get anything fixed. I planned on actually riding this summer!.....Basically what im asking is advice. What do you guys think maybe the problem and is it a basic enough for me to do myself?

  • Ga450owner

Posted July 20, 2008 - 10:32 AM


My answer yes of you have mechanical aptitude and patience.....and have no problem working on engines.
If not find another reputable mechanic that can fit it in......:thumbsup:

  • William1

Posted July 20, 2008 - 11:32 AM


Have to wonder where the 'rag fibers' came from.

Finding metal chips and other crappola would make me want to do a complete tear down, replacement of any questionable parts, a complete cleaning and reassembly. Read the service manual, do you think it is a job you could handle?

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