Of all the people having oil blowing or misting out of their breathers how many are running a Harley oil cooler?
I have been racking my head as to why some of our bike do this.
Blow by including improperly seated rings broken or stuck rings scored cylinder , oil pump O ring not installed properly which results in wet sumping and oil carry over, scavenging pump not working right do to broken or improperly installed gyros, breather valves dried out cracked or stuck.
All of the above check out OK on my bike. When I had my engine apart and was reinstalling my oil cooler filter adapter plate which is a Harley part I noticed how small a slit there was for the oil to travel through. Could this be the smoking gun on restricting oil flow which allows the sump and cam chest to fill with oil during sustained high speeds because the scavenging side of the pump cant keep up with the extra demand of oil at the higher rpm?
Of all the people having this problem are you running an oil cooler and who's are you running?

 

an obstruction there will show up on your oil pressure gauge and oil would be diverted thru the bleed off out of the system

the service manual shows the path the oil take and how it is routed and controlled


more than one rider has put the seal in wrongway around when installed the adapter plate- but they figure it out soon enough

mike

 

This is not an obstruction more like a restriction. I have a hard time grasping how oil goes through that little slit. Again Im just trying to collect data to see if this could be something.

 

I've got the Fueling adapter and the Harley oil cooler. 2000 Road King, pretty stock. I changed the umbrella valves and stuff when I did cam chain tensioners. I've got a breather line running to air below the trans, never leaves a drop on the floor. oil pressure guage shows between 30 & 40 except at idle, then drops to between 10 and 20. I do get leaks at the oil pressure lines if I don't tighten the clamps once in awhile, but that's rare. I'm using fuel injection line clamps, now.

 

Ok we now know a fueling cooler adapter does not cause any restrictions.

 

I put the HD oil cooler on about 3 years ago and haven't had a problem. Yet

 

well it's apples- oranges

the HD is limited to about 33 psi...the bleed off is before the sender and the filter- with or without cooler

Mike

 

Small sample size but I have had 2 TC touring bikes, '05 FLHTC and '10 FLHTK.
The '05 had no oil cooler and the '10 has a factory cooler. Neither has produced more than a slight film on the AC backing plate between 5000 mile oil changes. Never a drip or any on the engine around the AC. Both have high flow AC. The '05 a Screaming Eagle, the '10 a Fuel Moto.

 

Thanks for the input your engine is stock displacement so that helps narrow things down.

 

Assuming the bike is the motor in your sig..

First off an oil cooler restriction will only effect the feed side and will not effect the scavenge side. Might actually make misting better. Less oil into the motor. Since it looks like you have an SnS 3 rotor pump you likely have the best scavenging possible.

Seeing as how the motor is a 117, you will likely have some sort of misting.. Forged pistons don't seal well when the motor is cool. Once up to temps ring seal is better. Ring seal needs to be good. Have you leak tested the motor?

I have a 131 ci TC and a 113 ci evo that both have breather traps to collect the mist.. You might want to think about adding one. There are a number of things you can do and check to improve the misting but simply catching the mist is easiest..