Oil drips from throttle body onto the air filter.

[Huckster FLHRC]

I have a 103 motor with 7500 miles on it. It seems to have a case of “clap”, dripping oil from the throttle body onto the air filter. Oil is where it should be, just did the 3 hole change, 4 quarts of 20-50 Mobil One. The bike was a used buy and it was discovered the same day of purchase, when I took it home and popped off the air filter for a look-see for any issues like this. It’s obviously blow-by from the intake valves. Valve seals shot from age? It’s a 2012. Thoughts?

 

[Huckster FLHRC]

I have a 103 motor with 7500 miles on it. It seems to have a case of “clap”, dripping oil from the throttle body onto the air filter. Oil is where it should be, just did the 3 hole change, 4 quarts of 20-50 Mobil One. The bike was a used buy and it was discovered the same day of purchase, when I took it home and popped off the air filter for a look-see for any issues like this. It’s obviously blow-by from the intake valves. Valve seals shot from age? It’s a 2012. Thoughts?

After a little more research, I discovered it’s a design issue, similar to that of a PVC system.

 

[Justjake]

Try running your oil a bit lower in the oil tank, this seems to work for some

 

[Uthud]

Probably not a serious issue. The crankcase vents through the heads; there are oil separators in the heads to help control the oil in the mist. The vented air leaves the heads through banjo like bolts, and is directed to the air intake.
There are aftermarket air intake systems that help sometimes.
I’m sure others will have more information about this for you.

 

[Jeff Klarich]

Venting to the atmosphere will minimize carbon build up as has been pointed out. You didn't mention if you are still running the OEM air filter and backing plate. If you are, you have some work to do.

If you have not upgraded to the SE Stage I A/C, you will need one of the SE kits depending on the T/B size; IIRC, the Dynas are equipped with a 50mm T/B but not sure. There are two kits, PN 29515-08 for the 58mm T/B and PN 29260-08 for the 50mm T/B. You will need to drill and tap the backing plate for barbed fittings for hoses to route the crank case ventilation away from the T/B to an external exit. You will also need to block off the internal breather passages in the backing plate.



As others have pointed out, there are a variety of ways to route the hoses to an external exit but most use a "T" fitting to connect the two breather hosed behind the air cleaner housing and route a single hose to a catch can or an external exit.

On one bike, I made a catch can from PVC pipe and filled it with the same mesh that is used in the cylinder head breathers. The crank case mist is vented to this can and the "wet" stuff collects on the mesh allowing the crankcase pressure to vent out of the can to a single hose that is routed between the cylinders and out to the same location as the transmission vent. A small in line fuel filter for lawn mowers is plugged into the end of the vent hose at the exit. I have never seen a drip from that system and have never drained any fluid from the catch can.

(Disclaimer) I may not always be right but at least I tried. 05 Ultra Classic 95 ci.
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[Justjake]

Some of these engines are spitters right from the factory
The biggest problem they faced was out of round cylinders ( poor quality control), they will continue to spit oil

 

[Jeff Klarich]

Here's a better explanation.

1. Here Ya go.
   
   I have up-graded the Air Cleaner on my '12 Ultra Classic to the SE high-flow one (see pix below). This kit includes the mounting bolts shown in the first set of photos below that are hollow with a port in the side that vents the crankcase to the air cleaner and engine cylinder intake through ports in the back plate. This allows the oily mist from the crankcase to be sucked into the cylinders and "burned". But I do not like this for a couple of reasons:
   1. The oily crankcase vapor accumulates in the air filter area and eventually drips out of the A/C cover onto the engine making a mess
   2. Burning the oily mist in the engine contributes to carbon buildup and fouling of the IAC over time
   So I decided to replace these mounting bolts with the OEM ones from the original backing plate that look like the second set of photos below. Those are also hollow, but they do not have a port in the side of the bolt but rather have a nipple on the end of the bolt (see pix). So I used some fuel hose from the auto parts store and routed that out from behind the cover and down between the engine and the tranny on the right side below the engine about 3 inches (see last 3 pix below). So any venting of the crankcase now blows down below the bike.
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   Cheers,
   
   TQ
   
   Last edited: Sep 12, 2017
   Please stop by the "The Self-Help pages."
   
   Jeff Klarich, Jul 9, 2021Report
   #21+ QuoteReply
   
   
2. 

 

[Huckster FLHRC]

Venting to the atmosphere will minimize carbon build up as has been pointed out. You didn't mention if you are still running the OEM air filter and backing plate. If you are, you have some work to do.

If you have not upgraded to the SE Stage I A/C, you will need one of the SE kits depending on the T/B size; IIRC, the Dynas are equipped with a 50mm T/B but not sure. There are two kits, PN 29515-08 for the 58mm T/B and PN 29260-08 for the 50mm T/B. You will need to drill and tap the backing plate for barbed fittings for hoses to route the crank case ventilation away from the T/B to an external exit. You will also need to block off the internal breather passages in the backing plate.



As others have pointed out, there are a variety of ways to route the hoses to an external exit but most use a "T" fitting to connect the two breather hosed behind the air cleaner housing and route a single hose to a catch can or an external exit.

On one bike, I made a catch can from PVC pipe and filled it with the same mesh that is used in the cylinder head breathers. The crank case mist is vented to this can and the "wet" stuff collects on the mesh allowing the crankcase pressure to vent out of the can to a single hose that is routed between the cylinders and out to the same location as the transmission vent. A small in line fuel filter for lawn mowers is plugged into the end of the vent hose at the exit. I have never seen a drip from that system and have never drained any fluid from the catch can.

(Disclaimer) I may not always be right but at least I tried. 05 Ultra Classic 95 ci.
Quote Reply
R

Venting to the atmosphere will minimize carbon build up as has been pointed out. You didn't mention if you are still running the OEM air filter and backing plate. If you are, you have some work to do.

If you have not upgraded to the SE Stage I A/C, you will need one of the SE kits depending on the T/B size; IIRC, the Dynas are equipped with a 50mm T/B but not sure. There are two kits, PN 29515-08 for the 58mm T/B and PN 29260-08 for the 50mm T/B. You will need to drill and tap the backing plate for barbed fittings for hoses to route the crank case ventilation away from the T/B to an external exit. You will also need to block off the internal breather passages in the backing plate.



As others have pointed out, there are a variety of ways to route the hoses to an external exit but most use a "T" fitting to connect the two breather hosed behind the air cleaner housing and route a single hose to a catch can or an external exit.

On one bike, I made a catch can from PVC pipe and filled it with the same mesh that is used in the cylinder head breathers. The crank case mist is vented to this can and the "wet" stuff collects on the mesh allowing the crankcase pressure to vent out of the can to a single hose that is routed between the cylinders and out to the same location as the transmission vent. A small in line fuel filter for lawn mowers is plugged into the end of the vent hose at the exit. I have never seen a drip from that system and have never drained any fluid from the catch can.

(Disclaimer) I may not always be right but at least I tried. 05 Ultra Classic 95 ci.
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I like it!