My Evo is puking oil and I’ve done just about everything I can think of to fix it. I’ve read all of the “oil in my air cleaner” threads on the site and performed pretty much all of the fixes. I’m at a loss. Here’s the scoop, condensed as much as I can get it.

I have a 1999 Softail FXST. I bought the bike not quite 2 years ago with 10k miles. It now has 21k miles. It has had leaks from the rocker covers and the air cleaner since last summer. I pulled the engine over the winter to paint it and put it back in without changing anything but the rocker cover gaskets. I have no rocker leaks now, but I’m getting oil coming from the air cleaner. It’s getting all over the pipes and the right side of the bike and it’s a real pain and it’s getting all over my pant legs when I’m going to work.

I’m running Mobil1 20/50 synthetic. I was running a cheap oil, but replaced it hoping it would cure the leak. It didn’t. Next I ran the oil low, lower than it should be, and that didn’t stop the leak.

I pulled the front rocker cover and replaced the umbrella valve and drilled out the oil drain hole some to hopefully get the oil out of the rocker box faster. That didn’t help.

So, I bought an S&S reed valve to replace the stock plastic breather. That didn’t help.

Thinking I might have a TC filter instead of an Evo oil filter I changed it with one I KNEW was an Evo oil filter. That didn’t help.

Fed up with the oil on the bike I decided to run the breathers to a line that went up under the tank, down the backbone and into a little bottle under the seat. Not only did that not help, it caused a lot of oil to puke out of the oil tank through the stopper. I guess I restricted the breather too much with my plumbing (5/32 vaccum hose.)

I just performed a compression test to see if I might have a ring problem, meaning blowby and too much crankcase pressure. I have 150 psi front and back. I don’t think I have a ring problem.

Given the amount of pressure sent back to the oil tank I don’t think I have a scavenger problem. Since the oil flows at highway speeds – not before – I don’t think I have an oil pump check ball problem.

There you go. I’ve done everything I can think of to stop the oil from blowing out through the breather. What else is left to do?

 

Like the problem I have been dealing with. I have been told by lots of people on here that I am running too much oil in my motor. I know I'm not. Every time I would lean my sled over the oil would pour out the air cleaner cover. Well i just tied in the two breathers together and ran a tube out the botom of the bike so the oil goes out the bottom and not all over the bike. With Synthetic oil, if you have a leak or its comming out, it will leak more and come out more, thats what it does, its more slippery. I have seen these catch cans that you can plumb in but they look hinky!

 

Too much oil in the motor applies to twin cams, not Evo's. The Evo is a dry sump. The dipstick doesn't even have an upper level line. It just has a minimum line. The manual says to fill it all the way to the stopper. If you put in three quarts, which is what the manual says is the capacity, then that's pretty much how full it's going to be.

The bike isn't designed to spit so much oil out of the breather. So, running a line to the ground or a catch can is just covering up the symptom and not fixing the problem. I want to fix the problem.

 

Just thinking out loud now...

Assuming this problem did not exist before you pulled the engine...

Assuming you are not overfilling the tank, which will cause this problem, because when the tank is overfull, the oil will obstruct the breather and return openings in the tank and cause restriction to the scavenge system.

Sounds like there might be a scavenge problem.

Have you double checked your oil hose routing, all hooked up to the right place? Lines connected to the filter correctly? Correct breather line connected to the tank?

Check that the oil lines are not kinked, or obstructed, especially the scavenge line.

You might also check out the oil pump if everything else looks good.

The shop manual has an in depth method for checking the pump.

 

The TC is also a dry sump engine. I don't think H-D ever built a wet sump engine.

 

Terry, too much oil in the motor absolutely applies to Evo`s. If you fill a Softail tank up to the stopper, it is going to dump out the breather, every time. I`ve been living with a Softail Evo for almost 22 years- trust me. The manual is wrong on how much oil to put in a softail oil tank.

Put 2-1/2 quarts into the tank and see what happens.

 

It was there before I pulled the engine. I just fixed the rocker leaks when I had the engine out.

The manual indicates the tank does not overfill. In fact, the manual says to fill the tank to the stopper. Overfilling the tank is not the problem.


I wondered about that. But, I became unsure when oil started blowing out the oil tank. I guess that could be unrelated to oil volume and just a product of too much pressure coming back through the vent passage to the tank.

Checked, checked and double checked.

That'll be the next step, I guess. Sure does seem weird for the oil pump to develop a problem with no more miles than I have. Not out of the question, but definitely weird.

Thanks for taking the time to respond, Dan, I really appreciate it. I need all the minds I can get.

 

The manual indicates the tank does not overfill. In fact, the manual says to fill the tank to the stopper. Overfilling the tank is not the problem.

Terry please read my last post, about overfilling the oil tank. I think that is your problem. The manual is wrong when it comes to filling a Softail oil tank. Try running with 2-1/2 quarts in the tank before you do anything else.

 

From my original post:

It's not an overfilling problem.

 

Try running with no oil and see if your problem goes away

ok....bad joke....don't do that

Just throwing something out there since I am no engine expert...but if the timing mark on the breather gear is not properly matched to the cam gear, could that throw things off enough to cause your problem? Maybe if the cam was replaced it wasn't lined up right when reasembled...just reaching because I replaced cam recently and could see how that could easily be misaligned.