Oil in air box

[karl]

I’m surprised no one has made a catch can to vent the separator into, instead of the airbox.

I believe this is the intent of the separator, with a catch can you would not be recovering oil to the oil tank and could eventually move all your oil to the catch can.

 

[1999 Fatboy]

I too have a oil in the airbox issue with my 2018 Viper and not from overfilling or a roll over. Does anyone think there would be issues by plugging the airbox hole that the separator tube goes into and attaching a hose to that tube and running it out the bottom of the sled thereby bypassing the airbox?

 

[1999 Fatboy]

I'm bypassing the air box, I've already ran a high temp. hose from the separator tube that went into the air box down through a hole I drilled in the plastic about 4" beside the muffler and put a plug in the grommet that is in the airbox.

 

[grizztracks]

I too have a oil in the airbox issue with my 2018 Viper and not from overfilling or a roll over. Does anyone think there would be issues by plugging the airbox hole that the separator tube goes into and attaching a hose to that tube and running it out the bottom of the sled thereby bypassing the airbox?

If the oil separator canister is not draining properly to the oil tank then the separator could be overfilling and pushing oil into the air box. You could try removing the separator and flush or replace it. Also make sure the drain hose has no blockage.

If it's continuously pushing oil out the vent then there's an underlying problem that need to be corrected. If the oil tank is properly filled and the sled hasn't been rolled then minimal oil should reach the air box. Running the drain hose to the ground will keep the engine compartment cleaner but it'll continue to dump oil which isn't normal.

 

[1999 Fatboy]

If the oil separator canister is not draining properly to the oil tank then the separator could be overfilling and pushing oil into the air box. You could try removing the separator and flush or replace it. Also make sure the drain hose has no blockage.

If it's continuously pushing oil out the vent then there's an underlying problem that need to be corrected. If the oil tank is properly filled and the sled hasn't been rolled then minimal oil should reach the air box. Running the drain hose to the ground will keep the engine compartment cleaner but it'll continue to dump oil which isn't normal.

I’ll definitely keep a close eye on the oil level, I’ve never had to add oil during the season because of low levels so that leads me to believe that it’s a normal amount being pushed out and it doesn’t take much to make a mess. The next time I’m under the hood I’ll pull the separator and clean it out and monitor what happens, thanks for the input.

 

[Big Pussy]

The continual complaints of oil in the air box are troubling. I keep seeing the posts on this forum so I thought I would explain what is happening here so all that actually read this can understand what is going on.
First of let me say that Cat sleds were made with an oil tank with a sight glass on the side. Very convenient, you don't have to mess around with dip sticks, just start the sled and watch the oil level come up as the pump empties the sump and returns the oil to the tank. Cat designed the sight glass to be the oil level and no higher than the top of the glass. Once you fill it higher than that, you don't know just how high it actually is.

Here is a shot of the Cat oil tank. Observe where the sight glass is. The Yamaha tank will have a casting mark where the sight glass should be.

Here is what the inside of the tank looks like. The oil is returned through the elbow fitting into the can inside the tank. The can separates the air from the oil with the oil running out the bottom slots and the air coming out the top slots. The air then goes out the top tank fitting to the rollover valve and then to the air box. There is plenty of air pumped out of the sump along with the oil and it has go somewhere.

This shot shows the Yamaha dipstick inserted in the tank to show where the oil level would be on the dipstick. This dipstick is from a 2017 Cat and no sight glass. I suppose Yamaha needed to have the dipstick so the sled would look like a Vector. See the tip of the dipstick in the sight glass window. So the oil level should be about 1/2 inch up from the bottom of the dipstick.

More pictures to follow. Can't add more now. Continued.

 

[Big Pussy]

This shot shows the tip of the dipstick through the sight glass confirming the oil level is just up the tip of the stick.

Now here is a shot of the dipstick. So who made the oil level lines in the wrong place. Even the low line is too high. Also most people just have to fill the tank above the full line for good measure. So all that air bubbling in from the scavenge pump blows the grossly high level right out the top of the tank and into the air box, OR out on the ground if you have bypassed the rollover valve. So when you see the level go down, you fill it up again and keep pumping the oil out.

STOP OVER FILLING THE TANK.

 

[super1c]

Had this issue till my dealer mechanic told me basically the same thing. I was way over filling.

 

[GR8BBQ]

Brake clean will be fine

Careful not to get brake clean on frogskin that's on the airbox. It seems to eat away the glue that holds the frogskin on and you will have to reattach it.

 

[DennyTuna]

It's also best to have the sled at normal operating temperature and on level ground when checking oil levels. We bring the oil level to bottom line on the dip stick just so we don't overfill.