Google
 
Web V2-Forum.com

View Full Version : oil keeps coming out of my breather!! compression is good


TomSchneider
2nd August 2009, 11:25
good afternoon all. i have a 99 softail (EVO) with 150 lb of compression in both cylinders. it has an S&S carb on it. i keep getting oil coming out of the breather that goes between both rockers and goes into the carb. drips a bit, seems like more when you had it at higher rpm's. i am assuming i am pressurizing the crankcase with compression from the combustion chamber........but my compression is good..............any ideas?

someone on another forum mentioned maybe too much oil in tank.......my level is between the 2 lines though..............i did lower the bike a little.....

Y2K
2nd August 2009, 14:54
This is an age old problem common with Harley motors,even the old bikes with just a crankcase vent tube that wasn't hooked to the breather will pump out oil under certain conditions the most common being the tank overfilled.

Ok a couple questions....

Had the bike been sitting for more than a week or two without being run?

Did you recently add oil?

Did you check the oil level with a cold engine?

Is you air cleaner clean?

Is your tappet screen clean?

If the bike sat for an extended period it's common for oil to sump into the crankcase past the check valve,this will leave the reading on the dipstick low when in fact there is plenty of oil in the motor,add oil and you are now overfilled.
The old bikes like the '75 XLCH I had would just pump the excess out of the vent tube from the crankcase onto the ground and make a big mess under the bike.
Always check the oil with a warm motor to get an accurate reading.
Sometime in I think around 1979/1980 they ran the crank vent to the aircleaner so any oil mist would be burned in the engine,excessive oil from an over fill or a sump over time problem would fill the carb and aircleaner with a bunch of oil,my '84 FXR would puke it out all over the engine and of course smoke like all get out from a carb full of oil.:upeyes
Many of us simply unhooked the hose from the aircleaner box and ran it under the bike with a small filter on the end to keep dirt out.
No more oil in the carb and the aircleaner would last a lot longer.
Speaking of aircleaners,a dirty element will create a vacuum and that can suck oil up from the vent in excess to some degree,once it's oil soaked it's even worse so you'll want to clean yours real well.
Come the 1990's the venting moved from the case to the heads,some guys added an inline filter ahead of the aircleaner to vent some of the pressure to the atmosphere and help keep oil out of the airfilter box,sounds like you may have this set up.
When you change your oil you are supposed to clean the tappet screen inside the plug behind the rear lifter base,if this gets plugged up with gunk it could add to your problem,I would clean mine about every 4th oil change.
If this problem occurred suddenly after the bike was lowered maybe the dipstick is not accurate anymore but I can't imagine it being that far off,still you could start fresh by doing an oil change with the correct amount of oil and checking the dipstick after you fill it.
Even if the bike had not been sitting a while there is a chance the check valve on the oil tank stuck open and allowed oil to sump to the crankcase,you may have checked and added oil causing the problem.
I have found that Evo and TC motors rarely need oil added between changes if they are in good condition.
There are a few possible issues like breather gear timing that can cause this,if you haven't changed cams or anything and the bike doesn't have high mileage I doubt there is an issue there but it's possible.
My bet is you have too much oil in your bike and a aircleaner element that needs the oil cleaned out of it.

TomSchneider
2nd August 2009, 15:07
good info here for me to check, thankyou........this is my first BT EVO. i have owned over 15 ironheads but this my first BT.


the bike has 29,000 miles on it.

Had the bike been sitting for more than a week or two without being run? my bike sits most of the week and i ride it on weekends.

Did you recently add oil? i did an oil change when i first got this bike and thats when it seems to have started but my level was in the middle of the 2 lines.

Is you air cleaner clean? has oil around the bottom from this problem

Is your tappet screen clean? i have never cleaned it, just got the bike a few months ago.

** can i remove the tappet screen with oil in the bike and clean it and reinstall? or do i have to do another oil change and drain it first?

** i didnt know EVO's sumped like ironheads????

after reading this....i did a search on tappet screen............do i need a special tool/wrench to remove it as mentioned in another thread?

if the dip isn't accurate due to lowering... how far below the bottom of the fill tube is a good amount to have? some one in another forum mentioned he fills an inch under fill tube.... i think that is close to where i am......i will find where that tappet screen is and clean it out. i will clean my filter off and drain some more oil out and see what happens................thankyou for the very informative response!!!

Y2K
2nd August 2009, 16:03
Yeah there's a special tool for the tappet screen plug.
As for the oil level,just fill with the recommended amount then check the dipstick for a reference point is what I would do.
I think most Evos hold 3 quarts like my FXR did but it could be model specific.

hutch52
2nd August 2009, 16:07
This is an age old problem common with Harley motors,even the old bikes with just a crankcase vent tube that wasn't hooked to the breather will pump out oil under certain conditions the most common being the tank overfilled.

If the bike sat for an extended period it's common for oil to sump into the crankcase past the check valve,this will leave the reading on the dipstick low when in fact there is plenty of oil in the motor,add oil and you are now overfilled.
Sometime in I think around 1979/1980 they ran the crank vent to the aircleaner so any oil mist would be burned in the engine,excessive oil from an over fill or a sump over time problem would fill the carb and aircleaner with a bunch of oil,my '84 FXR would puke it out all over the engine and of course smoke like all get out from a carb full of oil.:upeyes
Many of us simply unhooked the hose from the aircleaner box and ran it under the bike with a small filter on the end to keep dirt out.
My bet is you have too much oil in your bike and a aircleaner element that needs the oil cleaned out of it.

I found this to be a problem with my EVO also but I unhooked the hose from the aircleaner box and ran it under the bike with a small filter on the end to keep dirt out.

I found that if my bike sat for over a month period it was common for oil to blow out the vent tube upon start up

I think its a good suggestion about keeping the oil an inch or so under the fill tube. Also i really never had to add much oil between changes.

Good luck with this this keep us posted on the fix

TomSchneider
2nd August 2009, 16:39
I found this to be a problem with my EVO also but I unhooked the hose from the aircleaner box and ran it under the bike with a small filter on the end to keep dirt out.

I found that if my bike sat for over a month period it was common for oil to blow out the vent tube upon start up

thats what is weird, i dont think it does it on startup..........more like when you are riding a bit and stop.

Y2K
2nd August 2009, 22:12
thats what is weird, i dont think it does it on startup..........more like when you are riding a bit and stop.

My old FXR would build up oil in the aircleaner after a long run at high speeds especially on a hot day,that is one reason I ran the breather under the bike.
It was a viable option on the early Evos and late Shovels because they didn't breath through the heads like yours.
My Twincam even does this to some degree,my motor is pumped up and has the SE open breather so a little oil does escape when I run long and hard,again especially on a hot day.

TomSchneider
29th October 2009, 15:20
thanks for the help/advice on this problem. i grabbed a tool off ebay to clean the screen (which turns out it wasnt dirty at all). lowering the oil level seemed to help a bit. i still have some coming out, but not anywhere close to the levels i was seeing. i was thinking of running a hose out the bottom of the bike, but i read that the filters become clogged up from road grime/dirt/dust etc and wont breath properly.......still kicking around the idea.

07classic chop....
29th October 2009, 16:10
Is the oil comming out of your carb where the breather tube go`s into it?
or is the oil leaking out of the hose where it connects to your rocker`s?
On my bike i had some oil comming out of the hose where it connects to the rockers and the oil would leak down and go across the fins on the cylinder head .... had a factory clamp that was a pliar clamp (not a hose clamp)and those kind of pliar clamps suck...leak all the time....i replaced it with a stainless hose type clamp.....(no more oil leak).....at that time my bike only had 200 mile`s on it......

TomSchneider
29th October 2009, 16:20
Is the oil comming out of your carb where the breather tube go`s into it?
or is the oil leaking out of the hose where it connects to your rocker`s?
On my bike i had some oil comming out of the hose where it connects to the rockers and the oil would leak down and go across the fins on the cylinder head .... had a factory clamp that was a pliar clamp (not a hose clamp)and those kind of pliar clamps suck...leak all the time....i replaced it with a stainless hose type clamp.....(no more oil leak).....at that time my bike only had 200 mile`s on it......

my bike has an S&S carb on it. the breather hose goes on to the aircleaner plate that is mounted on the carb and heads. the breather outlet is inside the air filter ring. the oil is coming out of the hose, running down the plate onto the inside of my airfilter, runs through the filter onto the outer metal S&S cover and then leaks out, falling on my crankcase by the lifter blocks and some flies back on my oil tank and on me.......lol

Y2K
29th October 2009, 17:34
thanks for the help/advice on this problem. i grabbed a tool off ebay to clean the screen (which turns out it wasnt dirty at all). lowering the oil level seemed to help a bit. i still have some coming out, but not anywhere close to the levels i was seeing. i was thinking of running a hose out the bottom of the bike, but i read that the filters become clogged up from road grime/dirt/dust etc and wont breath properly.......still kicking around the idea.

Just get the cheap toss away paper element filter and change it once in a while.;)