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Crankcase breather mystery

ausibatla

Member
G'day fellas,
just got my arm out of a sling after a shoulder operation. The bike a 1990 1340 Evo softail springer sat idle for 8 weeks. It was running sweet before I parked it up and I did a bit of work on the bike while it was sitting in the workshop but the only thing I did to the engine was swap the 32 amp regulater to a chrome one. Yet when I started it up the oil wasn't returning to the tank it was being pumped straight out of the crankcase breather onto the ground. Has anybody come across this before? If so what has caused it. Appreciate any advice.
Cheers,
:cheers :AUSTRALIA
 
It may be that the check valve is leaking allowing the oil to push past it and move from the oil tank to the sump
As the pistons in the engine go down the air in the crankcase is pressurised and some of the oil is expelled through the breather
letting the bike idle for a wee while should allow the oil pump to move the oil back into the oil tank revving the engine will just create more pressure in the crankcase and oil will be expelled
I am sure there are some tips somewhere on this site for cleaning the check valve
Here is some info on sumping
Harley Davidson Forums

Brian
 
It may be that the check valve is leaking allowing the oil to push past it and move from the oil tank to the sump
As the pistons in the engine go down the air in the crankcase is pressurised and some of the oil is expelled through the breather
letting the bike idle for a wee while should allow the oil pump to move the oil back into the oil tank revving the engine will just create more pressure in the crankcase and oil will be expelled
I am sure there are some tips somewhere on this site for cleaning the check valve
Here is some info on sumping
Harley Davidson Forums

Brian
fin 676,
thanks for that tip mate. I'll check it out in the morning.
Cheers.
 
IF Totally NO Oil in the tank? The oil pump might not return oil... I'm Guessing on this.
I have always had oil return AT IDLE Only...
Like fin says Higher RPM than Idle will whip the oil into a air foam and a MESS... That oil PRESSURE is what Pushed it out on the ground. Must have ALL leaked DOWN into the motor.

I know on the TC motors there is a Plug at the bottom of the motor that can be CAREFULLY taken out to remove Sumped oil.

The evo is toooooo long back in memory for me as I did own a 97 model FXDS.:D

Look and see at the bottom of the motor for a pipe plug and you.ll need an allen to remove it. Careful cases can CRACK... Drain and that will help that TOO MUCH oil there.

Put at least a quart into the oil tank after you drain oil out the sump. IF you drain out Three quarts???? install (fresh) the same amount into the oil tank.

signed....BUBBIE
 
It may be that the check valve is leaking allowing the oil to push past it and move from the oil tank to the sump
As the pistons in the engine go down the air in the crankcase is pressurised and some of the oil is expelled through the breather
letting the bike idle for a wee while should allow the oil pump to move the oil back into the oil tank revving the engine will just create more pressure in the crankcase and oil will be expelled
I am sure there are some tips somewhere on this site for cleaning the check valve
Here is some info on sumping
Harley Davidson Forums

Brian

IF Totally NO Oil in the tank? The oil pump might not return oil... I'm Guessing on this.
I have always had oil return AT IDLE Only...
Like fin says Higher RPM than Idle will whip the oil into a air foam and a MESS... That oil PRESSURE is what Pushed it out on the ground. Must have ALL leaked DOWN into the motor.

I know on the TC motors there is a Plug at the bottom of the motor that can be CAREFULLY taken out to remove Sumped oil.

The evo is toooooo long back in memory for me as I did own a 97 model FXDS.:D

Look and see at the bottom of the motor for a pipe plug and you.ll need an allen to remove it. Careful cases can CRACK... Drain and that will help that TOO MUCH oil there.

Put at least a quart into the oil tank after you drain oil out the sump. IF you drain out Three quarts???? install (fresh) the same amount into the oil tank.

signed....BUBBIE

Good advice from Bubbie and Fin, not uncommon for an Evo softail to do this with the gravity flow from the oil tank past the oil pump check ball Harley Davidson Forums
 
Brian, Bubbie & Jack,
thanks for the advice and articles. I am a lot wiser. Am going over to remove check valve and give it a clean though I did weaken and start it up again last night and hardly any oil came out. I hope I don't have to drain the oil to do the check valve or I will have oil everywhere. Strangely while running it just cut out. I have ignition, horn, lights, indicators but when I hit the starter there's nothing. Not even a click from a solenoid that's trying to work. Very strange. I'm hoping it's something to do with the fuse setup on these old bikes where the circut is broken then resets again. I'm hoping it will start this morning.
Cheers.

Brian, Bubbie & Jack,
thanks for the advice and articles. I am a lot wiser. Am going over to remove check valve and give it a clean though I did weaken and start it up again last night and hardly any oil came out. I hope I don't have to drain the oil to do the check valve or I will have oil everywhere. Strangely while running it just cut out. I have ignition, horn, lights, indicators but when I hit the starter there's nothing. Not even a click from a solenoid that's trying to work. Very strange. I'm hoping it's something to do with the fuse setup on these old bikes where the circut is broken then resets again. I'm hoping it will start this morning.
Cheers.
Thanks again you blokes. I sorted out the non starter issue. Just a wire had come adrift. 2 minute job. Started her up and hardly anything came out of the breather and eventually nothing at all. I couldn't get the ball out to check it. I have 3 magnets not counting magnetised screw drivers, and not one of them was small enough to fit inside or strong enough to lift it out. I will order a new spring and ball anyway and replace the old ones when I get another magnet that will do the job.
Cheers.
 
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Seems like it is not a big problem I hope that the oil has made it back to the oil tank until you get the check valve sorted it may be a good idea to do a daily check of oil level on days the bike is not in use, if the oil level starts to reduce in the oil tank start bike to get it back to the tank as it will be much easier on the engine if there is only a wee bit of oil in the crankcase rather than when it is full

Brian
 
Seems like it is not a big problem I hope that the oil has made it back to the oil tank until you get the check valve sorted it may be a good idea to do a daily check of oil level on days the bike is not in use, if the oil level starts to reduce in the oil tank start bike to get it back to the tank as it will be much easier on the engine if there is only a wee bit of oil in the crankcase rather than when it is full

Brian
Thanks Brian. Will take your advice and keep an eye on it. I was a bit worried at first because I couldn't see the oil returning to the tank but it was moving very slowly and it was aerated, the movement ceased when I turned it off. The temperature increased to 100 degrees after running for a short time so it must have been circulating to get warmed up and the oil pressure light didn't come on though it is working. I seem to recall checking the oil return once before and when I removed the cap oil went everywhere. Also, the oil level remained constant.
Cheers,
Lloyd.
 
The 85 FLT that I had and gave to my stepson does it after every winter storage. I just route the hose down into a catch pan for the first start of the year and it is always good after that. I did go through and try and clean the ball check seat and replaced the ball and spring.
 
There always seems to be a lot of bubbles in the returning oil as when you look in the oil tank with engine running there is some froth on the top
Oil level should always be checked with the engine hot to get it to the correct level as there is always some in the sump which is returned to the oil tank when the engine is running
If oil tank is full when cold when the engine is started the oil gathered from the sump will cause the oil tank to overflow
I check for a presence of oil on dipstick prior to starting and check for correct level when hot after a wee while you get to know what a cold oil level should look like if it is way low then there could be a check valve error

Brian
 
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