09 KX250F Smoking a little?

[Rippin_RobMX]

Today me and a friend were riding through some trails and he was behind me and noticed that my bike (09 KX250F) was blowing out some black/blue smoke when i revved it hard and quick.
I've heard this about the different colors of smoke.
 
Blue = oil
Black = Fuel
White = Coolant/water
Only thing done to the bike is a yoshi exhaust: http://www.motosport.com/yoshimura-rs2-pro-series-titanium-full-system-exhaust
Change oil before 10hours Filter every other time.
New air filter when it gets dirty
Bike has 60+ hours when i bought the bike the person i bought it from said he had a shop adjust the valves. Not sure what shop.
Bike starts right up 1-2 kicks cold and usually starts with 1 kick when hot. Not sure about the piston probably factory.
Its the monster energy edition.
PO said it was never raced and only trail and woods ridden and man the plastics do show it lol
So my question is what would be causing the smoking? New to 4 strokes.. Thanks

[alward25]

Sounds like it is time to buy a 2 stroke so u can stop worrying about if your valve stem seals are a little worn.   It may be time for a freshen up. 250f's are not xr's being able to run for years without engine maintenance.

[motovet]

My first thought is having 60 hours on it that a new piston and rings are in order. You might be able to tell more by pulling the spark plug and checking it for oil. Rule of thumb is oil all the way around is rings and if it is more on one side then the valve seals/guides are leaking. A leak down test would help to see if the rings are wore, valve seals can be replaced without pulling the head off but unless someone else has a better answer, the head will need to come off to check the valve guides. You said the valves were checked shortly before you purchased it, usually that is just the valve to cam clearance and they would not see play in the guides or seals getting bad. Hope this helps

[Dutch-K5 Fan]

You need new piston valve springs(wil bring back 1HP) and seals at least.
10h with oil is 9 to long, oilfilter every other time is ok.
If you change piston your sellf, take the head with you to your raceshop to checkout the valve stems.

Blacksmoke = fuel??? Thats with Diesel


Dutchie

[KXDINO]

We rebuild 250f at 40 hrs new piston and valve stem seals at least at 80 hrs the same but include a cam chain and check cylinder real well as most of these are shot by then especially if fine dust is getting threw filter and oil changes are not done enough , very important on these new 4 strokes , watch cam journal wear especially on engines that don't get regular oil changes otherwise a new head and cams are in order.