Harley Davidson Motor Company. :D

How many changes in the breathing and oiling systems have been made since the breathing was moved to the heads? It didn't stop in 04.
The plastic breathers aren't the only plastic warping up there either. Look at the backplates of the AC. Especially the SE one. Plastic in or near the heads is asking for problems.

There were many changes.
Well since early IHs, we've had rubber jackets on the spark plugs on top of the heads.
My 98 has a plastic A/C backing plate with no damage from heat.
There are plastic jacketed throttle cables that lay next to the heads.
The plastic jacketed wiring loom rests above the heads.
Nothing new here?

My SE air cleaner warped the first year I had it. They gave me a new one for free and it's been fine ever since.

Overall plastic parts or not, the worst catastrophe I can remember that caused me to have to pull over, in all my riding was the battery cover coming off when I caught air on a huge heave on the Alaska highway. And then there was that time the belt broke on the way to work - only time the bike has ever been trailered. The grenade plate happened only 100 miles from home so I got lucky there.

So i'm apprehensive to try design changes, because it's been so darn reliable and maintenance free.

Not sure has HD changed the beathers at all since 04?.

Pretty sure they changed the design again. I know there are aftermarket replacements for those that are not plastic too.
The krankvent only makes it more maintenance free. If ever does need maintenance it's as simple as cracking it open and cleaning it.

Too many better air cleaners to mess with one like the SE and it's plastic backplate. I wanted the small, round nostalgic look or I'd be running a Hammer AC.
Not hitting my leg on it either. Hammer has an offset one to prevent this.

I know - hindsight - I bought the SE at the time because I was too cheap to buy a Forcewinder and didn't know about the Hurricane. SE was the most affordable thing I could find with a properly radius-ed inlet hole and decent filter. If I ever decide to push for 100hp it may become a weak link.

Also I like the stock look, and that the filter is mostly protected from splashing mud rocks etc. Painted my cover to match body color (not a fan of too much chrome) and for me it's not in the way.

No, they haven't. The breathers are the exact same parts throughout 2004 to 2019:

Breather, front: # 26010-04
Breather, rear: # 26011-04

An external seal, # 17393-07, was introduced in 2007, and there were new part numbers for the breather with the seal included:

Breather, front, with seal: # 26012-07 (# 26010-04 with # 17393-07)
Breather, rear, with seal: # 26020-07 (# 26011-04 with # 17393-07)

The umbrella valve was listed as a separate part in 2007-8: # 26856-89A. Does that mean that it is replaceable separately?

That's what I mean. There was a change. I see J&P sells them not compatible with my bike.
They're metal housings and come apart.
Alex at Hammer said his are slightly different than mine.

What change? The breather didn't change, nor did the rocker cover. Use the seal, or don't use the seal; whatever.

Just telling you what I've heard. Mine dont come apart. Apparently some do. I'm not using them so I never looked into it any further. Maybe not for sportsters Idk. But they're for rocker box assemblies, metal, and come apart.

Oil pump changed. Same part number. Can be used in earlier models. Bolts up the same too. Still changed with better scavenging or people wouldn't upgrade them. Jeezus.

I'm off. My dipstick probe type thermometer showed up. Going to test it against the infared and get my oil temps at different rpm.