2001 400ex Smoking Problem


Hey guys, I just picked up my 2001 400ex last week. And ever since, its been blowing some blue smoke. I think its burning oil. So i changed the oil and the oil filter, the oil was black. The original owner used 10W40 in it. I was told it may not smoke with 20W50 oil. So i tryed that instead. But its still blowing some smoke. Not as much as it was with the old 10W40 oil. Could it be the ring's? Or valves?

Thanks, Ryan.

20W50 and even 10W40 are way to thick for cold Nova Scotia weather! My mom use to live there, so I have heard the stories....

You might want to try an ester synthetic oil, like Maxima Extra. Synthetics have huge film strength, and will seal up loose tolerances better than any petroleum oil.

Most likely, it is your valve guides. They are always the first thing to go. But, it could be your rings, so you want to do a compression and leak down test to check that.

Valves are adjusted to spec???

What oil do you suggest? and nova scotia is like 10-30 Celesius in the sping, fall and summer ( not sure what that is in farenhite). 10W30. I'm not sure about the valves getting them adjusted soon.

Looking at my owner's manual, 10W30 is good from -15 to +30 degrees C. That is right in there for 3 season riding. If it is always on the colder end of the scale in winter (+5 or lower), I would run 5W30.

I run Redline for 10W30, and Maxima 530MX for a 5W30, but these are expensive high tech ester synthetics and you are unlikely to find them at a dealership.

For a less expensive petroleum oil, I like Maxima Premium. Strangely it doesn't come in 10W30 but does come in 5W30.

Thanks for the replys guys. And it also seems like it doesn't have as much power as it should... but i also drove a yz250f before i go it. Could there be something wrong with the bike power wise? or is it just me?

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