i have an 05 700 prairie that will bog down and start smoking really bad if im running it real hard up a hill or thru deep sno or mud but when i let off and work the throttle some it will clear up n run fine. i had the same problem with my dads 06 650 bf however i didnt feel it was necesary to tell him about since it cleared up and ran fine afterwards.

 

And your question is???
That's common on all Kawi v-twin engines. Just like what doc says, "Don't do it, if it hurts!"

 

oh yeah my question, what the hell causes it is there a breather that is plugged causing to much backpressure because it is not something that should happen

 

When you run engine at WOT, there is lots of oil splashing and oil foaming going on because it is wet-sump design crankcase. As the crankcase internal pressure increases, it pushes up excess oil into the air box via the breather tube. And the oil in air box goes into the carb/tb and gets burned, momentarilly causing engine to cough and you will see smoke coming out of your tail pipe. In hilly area, this is more likely to happen because breather tube gets more submerged into the oil at certain angle. Important thing is check your engine oil often to prevent seizure and fill it up to compensate the burnt/smoked oil. And oil is cheaper than engine!

 

thats the answer im lookin for i thought it had to have something to do with the breather i just wanted to make sure it wasnt plugged with mud or something thanks for the info

 

There are things you can do to stop this from happening.

First, Run your oil at the half way mark on the dipstick.

Second, you can add an overflow can to your system. It needs to have an Inlet, an Outlet and a Vent. A lot of us are using the YFZ Breather. The overflow needs to be mounted higher than the engine. You will also have to tap into the rear head. Some have run the return into the rear head valve adjustment cover. Here are a couple pictures of how it is set up. This shows the return being run into the rear head.

 

that sounds like a good idea i was trying to figure something like that out today and you just made it alot easier too bad the people at kawi arent as innovative as the guys that ride em thanks alot for the info im gonna fix mine this week

 

When you do internal mods to these Kawie V-Twins an overflow/vent can is an Absolute Requirement. If not, you will fill your airbox full of oil in a short time.

Like I said, just make sure the overflow can is mounted higher then the return on the motor. Otherwise you just end up making an external oil tank.

Also, it isn't a bad idea to put a small filter on the vent. Here is a photo of the filter I run (Small RED filter in the upper left hand corner). You can get them at most auto parts stores.

 

is there any particular size tank ill need im gonna start fabbin one out of stainless tomorrow at work

 

Not really, the YFZ tank is small. Between the hose and the return hose, they will hold a lot of oil.

What I would do is find a spot to locate it and to make it as big as you can to fit that spot.