Occasional Oil Blowby

[alhall88]

I know this has been talked to death but does anybody have a good idea on what causes this to happen off and on? First its an 04 117 not the 107. I changed my oil about 1000 miles ago then the last time out I had my back brake quit working on me and I couldn't figure out why at the time until I got home. The whole bike underneath was covered in an oil film then I realized the brake pads were soaked. So when I changed the oil awhile ago as I mentioned it was right on the 1-1/2 mark below the filler spout, and like I said it was fine for the 1000 miles. I ride it like I always do. The only thing I can think of that changed was that I did remove the front cylinder breather hose and cap it off.I just put it back on about 3000 miles ago to see if I could notice any difference. But before that I had this plugged off for several years and never a problem. The S&S manual states the front hose is optional and even if thats the case does keeping that hose on effect the pressure in the heads in any way even though the rear remains hooked up and vented to the ground (with the check valve at the end).

 

[Daddycool]

this probably isn't the cause but make sure you have an EVO and not a Twin cam oil filter. The dealer sold me the wrong one and it puked oil into my air breather. Good luck on finding your problem.

 

[Chopper Dave]

this probably isn't the cause but make sure you have an EVO and not a Twin cam oil filter. The dealer sold me the wrong one and it puked oil into my air breather. Good luck on finding your problem.

Al runs the K&P filter....just like myself and alot of others on here :up:

 

[Daddycool]

i tried to get in on the group buy but that didn't work out. (thanks for trying Jake)

 

[Vegas]

May be time for a leak down and compression check.

 

[alhall88]

May be time for a leak down and compression check.

Thats probably needed but I would think if there was an issue it would do this all the time. Just rode (hard) yesterday for about 150 miles at 90 deg. temps and not one drop of oil seen.

 

[Thumper]

Happened once?

1 1/2 below filler neck? My K9 is more than that but 2 years newer.

You do have the K&P filter, right. I would pull it off and check the spring.

 

[reloaderbmg]

check the check valve at the bottom of the rear cyl. vent hose.
if this is closed from oil in tube this will happen!, road crud
why take the front one off?

 

[alhall88]

Happened once?

1 1/2 below filler neck? My K9 is more than that but 2 years newer.

You do have the K&P filter, right. I would pull it off and check the spring.

Happened 2 times on me in the last 500 miles, I have the K&P filter. Check valve is also clear, when idling I put my hand under the bike and I had a felt the air pulsing out with a few drops of oil.(when its hot after a ride)

There really is no reason to pull the front hose off but I was wondering if it had anything to do with pressure building in the rear head. I'll be taking it out again shortly and beat on it some more see what happens. The manual states 1-1/2 below the fill spout at the rear (shallowest). This typically is around 2.7qts. of oil.

 

[lee]

well if its not the filter and its not the check valve the other obvious things would be the ring seals or the oil lines.

Here is a decent read on blow by but I doubt it will tell you anything you don't already know - sorry

Blowby in Motorcycle Engines - Tech Review - Motorcycle Cruiser

 

[Gas Man]

Good call lee.... have you checked the oil lines... maybe one is leaking and it only leaks when the oil pressure is up.

How far forward on the bike do you find oil trace?

Did you check the tranny to be sure its full? or do you have redline in it and the oil on the bike is obviously not red?

 

[alhall88]

There is no question where its coming from, its coming from the rear breather line. The one time I came home when it was spewing oil I grabbed the rear vent line with the motor running and got a handful of oil. Who knows went out today in the heat and beat it, and nothing not a drop.

 

[Gas Man]

OIC... so now just why... sorry for the cornfusion

 

[Vegas]

The only thing I can think of is the oil pressure relief valve is not working when you are having the issues. Pumping way to much oil to the top end. Otherwise pretty weird deal. I agree that a ring problem would show up more than once and a while.

 

[Gas Man]

What is the name of the vlv in the cam chest?

I remember the dealer once saying that there is a "ried" vlv that sometimes can stick open....

 

[dogvet]

check the check valve at the bottom of the rear cyl. vent hose.
if this is closed from oil in tube this will happen!, road crud
why take the front one off?

To eliminate the vacuum applied to the crankcase and oil tank. Oil pump ain't designed to suck oil over long distances, it's supposed to be gravity fed.

 

[dogvet]

I know this has been talked to death but does anybody have a good idea on what causes this to happen off and on? First its an 04 117 not the 107. I changed my oil about 1000 miles ago then the last time out I had my back brake quit working on me and I couldn't figure out why at the time until I got home. The whole bike underneath was covered in an oil film then I realized the brake pads were soaked. So when I changed the oil awhile ago as I mentioned it was right on the 1-1/2 mark below the filler spout, and like I said it was fine for the 1000 miles. I ride it like I always do. The only thing I can think of that changed was that I did remove the front cylinder breather hose and cap it off.I just put it back on about 3000 miles ago to see if I could notice any difference. But before that I had this plugged off for several years and never a problem. The S&S manual states the front hose is optional and even if thats the case does keeping that hose on effect the pressure in the heads in any way even though the rear remains hooked up and vented to the ground (with the check valve at the end).

Is this just happening when the bike is first started? Has the bike been sitting?