My 400 kills all flying bugs at startup. I have to make sure the garage door is open before I start it. It's an 02, but it does have that many hours on it. It's still on the original tires. Its hard to believe that the rings are worn already or even the valve seals.

Many 400's that I have ridden behind have the burnt oil smell. And I know a couple guys that have done a top end because of burning oil.

So, what's the deal? Do I need to do a top end? Or, is it something else? I heard that sometimes the crank case breather dumps oil into the air intake. Is this what's going on?

Thanks!

 

i went through the same thing with my kfx400. I just got it back with a new cylander, piston and rings, and its only an '05,. the onnlyy way u can know for sure is by looking inside.

 

It's just that this bike has low hours and is driven by chicks and kids.

I beat the living tar out of the Raptor with 10 times more hours and never burn any oil.

The 400EX is way more solid of a motor than a Raptor...so I thought.

It just doesn't compute. Maybe I put too much oil in it or something.

 

id do a compression test and a leak test. See if there is any oil getting through the rings.

 

Good idea. Does any one know what the cranking pressure should be?

 

new piston and rings solved my smoking and burning oil. Yep, should look inside to know for sure.
doesn't matter who rode it.

 

My g/f's 04 Yamaha Bruin started doing the same thing right after I changed the oil in it last fall. I used Castrol oil at the time so I changed it back in January to Amsoil 0w-40 synthetic and the oil burning stopped.
The money spent for oil and filter is cheaper than a top end rebuild.

 

the compression should be at 125. Do a leak test by putting a few drops of oil in the cylinder. Then do the compression test again. If the compression is lower that means ur leaking oil through the rings.

 

The thing just stopped burning oil on it's own. I did nothing to it. Maybe I put too much in it when I did the oil change. How many quarts is it supposed to take?

 

Just under 2 quarts.