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The Harley slobber... oil leak from the air filter.

oldscoolz

Member
I’ve had a sometimes annoying little leak from the air filter that occasionally drips down onto the camcase cover of my 2002 FLHRI. No big deal. It’s been goin on for years and over that period of time I’ve read a bunch of threads, looked at possible fixes, and considered whether they’re worth it. I’ve made sure not to overfill the crankcase oil, looked at other breather hose routing options, but didn’t do anything cuz it wasn’t that big a problem and I didn’t really want to reroute the breather hoses just to have the oil leak some other place, or buy a new stage I backplate. I’ve noticed that some of the newer stage I backplates are designed to direct the breather hose output into the throttle body intake.

While I’m doin some winter maintenance, I decided to take a look at this again and figured if I could put something together cheap that would accomplish what the newer backplates do, I’d give it a try. So this is it. Went to my local car parts store (AutoZone), spent between $10 and $11 for some brakeline parts, and made an extension for the aircleaner backplate. This uses a 3/8”-24 right angle for 3/16 brake line. Pics are included. The aircleaner backplate is from a stage I kit.

I’ll let you know how it works out.

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I have the stage 1 back plate on mine so for under 10 bucks worth of hose and T fitting I ran the hose down under the right side of my scoot and let it vent.
I've never had a drop on the ground but the tip of the hose will get moist to the touch. That tells me the engine is nice and tight with very little blow by.

If you check the self help section there's a step by step process on this method.
 
I can't see what the hoses behind the backing plate are attached to or how they are routed but the OEM breathers are already ventilating the crank case fumes and oil mist into the intake. I also can't see what is attached to the 90* elbow fittings screwed into the backing plate and am not clear on how the added apparatus will solve the issue. Venting the crank case mist which includes oil, water and uncombusted fuel back into the intake will accelerate carbon build up on the pistons which is not such a good idea.:(

The solution to the problem is to vent the head breathers to the atmosphere. If the OP has researched this, I am pretty sure he has seen various examples of how this is done. Don't know how many miles on the OP's bike but there could be a legitimate reason for the slobber; worn rings allowing some blowby and/or umbrella valves in the breathers that are not working properly and should be replaced; those are the first two places to look; a leak down test and inspection of the head breathers would be a good idea.

Once that is done; then route the breathers to the atmosphere. If there is blowby, a small filter attached to the end of the exit hose will catch it; I use a small fuel filter for a lawn mower. Some use a "catch can"; plenty of examples on the internet and other forums.

If going to the trouble to vent the head breathers; vent them to the atmosphere and not into the intake.;)
 
Once that is done; then route the breathers to the atmosphere. If there is blowby, a small filter attached to the end of the exit hose will catch it; I use a small fuel filter for a lawn mower.
I can't see what the hoses behind the backing plate are attached to or how they are routed but the OEM breathers are already ventilating the crank case fumes and oil mist into the intake. I also can't see what is attached to the 90* elbow fittings screwed into the backing plate and am not clear on how the added apparatus will solve the issue. Venting the crank case mist which includes oil, water and uncombusted fuel back into the intake will accelerate carbon build up on the pistons which is not such a good idea.:(

The solution to the problem is to vent the head breathers to the atmosphere. If the OP has researched this, I am pretty sure he has seen various examples of how this is done. Don't know how many miles on the OP's bike but there could be a legitimate reason for the slobber; worn rings allowing some blowby and/or umbrella valves in the breathers that are not working properly and should be replaced; those are the first two places to look; a leak down test and inspection of the head breathers would be a good idea.

Once that is done; then route the breathers to the atmosphere. If there is blowby, a small filter attached to the end of the exit hose will catch it; I use a small fuel filter for a lawn mower. Some use a "catch can"; plenty of examples on the internet and other forums.

If going to the trouble to vent the head breathers; vent them to the atmosphere and not into the intake.;)


dolt, that's what I was suggesting in post #2. I tried to find your post (that I used) but couldn't find it. It was the pictures of venting to the atmosphere using the stage 1 backing plate.

If you can find it that might be more helpful for the OP to see.
 
On closer inspection, I see what the OP has done. All he needs to route to the atmosphere is to remove those 90* elbows and plug the holes with what looks to be a 1/4" NPT plug. Disconnect the hoses from the rear of the backing plate and T them, as Jeff referred to in post #2, connect that T to a single hose and route that hose toward the rear of the bike. Or attach those two hoses to a Doherty type vented filter as shown in the third photo in the thread Jack was kind enough to find and link.

BTW, Jeff/Jack please walk me through the how to on attaching photos.
 
...Jeff/Jack please walk me through the how to on attaching photos.
First, put the edit cursor where you want to put the image.

From a hosting site, select the "image" on the top of the edit window. Then put the web link to the pic in the pop up box.

To up-load the image file, select the "Upload File" button from the bottom of the edit window. then select how you want the image displayed (thumbnail or full).

Alternately, just drag the image file from your file explorer to the edit window. This only works if you have flash installed and enabled on your browser.

Enjoy,
Rich P
 
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