List price for a pair of stock umbrellas is $24. So if a person is poor and trying to fix breather problem, thats a good place to start.

I wasn't going to waste any money on something I know is adequate at best and have to do it again 3 years from now if I'm lucky. Especially given I'd be pulling the rocker covers again too.

Just shot boiling water at 216° holding it 4 inches away just like the oil. I'm satisfied my temps are more than good.

I know.
But oil is also a coolant.
If it fails temps go up also.
Thinking out loud again.

I checked mine and I'm at an average 270-280F about an inch away.
Oil temp 194.1F
4 grand for 5 miles.
Haven't read anything on head temps yet.
Don't know if that's good or bad.

Mine was right around there except by the exhaust port. Even that just flashed 322 briefly then right back below 300. I may have pointed it closer to the pipe. I was moving it around looking for the hottest spot.
Otherwise I couldn't even find 290.
My oil temp at the tank was a steady 190. I just verified the accuracy of that.
I'll redo the head and shoot the other side closer to the combustion chamber but away from the exhaust where the temp sensor is on newer bikes and reading closer to 380.

I understand.
I guess I should've clarified.
I don't feel like oil gathers as quickly in the sump on rigids as they do on rubbermounts due to their oil squirters.
The pump delivers what it's capable of.
But I wonder, if once the restricted paths in the feed line are inline with the feed system and the pressure builds due to the restrictions, at what pressure could the pump backfeed (lowering static, basically it's own pressure relief back to the inlet side of the pump due to wear).

That's interesting.
I guess I didn't think about when they get stiffer, the don't open as well.
Even if they do seal on backflow, they could still raise pressure on downstroke.

+1

Thanks for the pic.
Yeah I can see the heat warping the plastic.
That would bypass the valve somewhat, not sure how much.
The air will take it's easiest route unless it get's restrictive.
I'm not a fan of the mesh.
Did you find a hole, even tiny, between the orange rubber and the opening for the mesh?
I can't see one in your pic either.

Take a good look at you measuring method. The temps you're seeing are actually low vs the usual norms. Oil in the tank you want to be 220-230F. Over 260F and you should be considering an oil cooler or working on your engine management, tuning. Head temps will be all over depending on where/how you measure. The exhaust port is hottest and the OE sender is really in a good spot. A "gun" won't give the same reading as the OE sender. No way you can "see" that area.
For oil temp a meat thermometer works pretty good if you lean the bike to the right so you can get it down in the oil enough.

The "guns" are great if you want to know your tire temps but not so good for oil or head temps.

Shot by the spark plug on both cylinders. 321/326. Oil at the tank 195.
8 miles at 4000rpm. Took an exit and idled.

I agree with Tomcat. These numbers are probably 30° at least low by this method of taking it. Especially the head temps.
But shooting the same way in the same location on the heads should alert us to any changes in the future. Use these as a baseline.
Actually mine's probably pretty close as I was slowed down then parking and idling. Probably a minute had gone by and cooled off a little? The 380 temps by those with sensors are temps taken while riding at higher rpm with a sensor inside the head.
I shot the same area by the plugs on both heads several times for consistency.

Yeah I've read the concerns with the oil temp dipstick being off.
I used the infrared in the tank to read 194 then 194.1F
I popped the oil temp dipstick off the tank at 190F
So that was two different measurements in the tank.

270-280F too low?
I got 290 or so near the exhaust but I was concentrating between the fins.
I know I can advance the timing and increase the heat.
I have no dialback light and have been tuning by ear.
She's got game I must say.
I gotsta figure a way to stop squealing tires on takeoff.
I am near bald now. :doh
But I've never heard of timing by heat. :dunno

So that may just be my timing setting at the moment.

Yeah, they drops in a hurry. Just the half mile off ramp I took cooled me down. I shot an inch from the plugs on the intake side of them. About as close as we can get to the sensor location.
I know my temps are more than good and if I take them this way all the time now I'll know if I have a problem.
Oil temps should be around 220-230. Even 250 is ok. But by the time I took the temp in the tank, it really had cooled I'm sure. 170 5 blocks later at home.

It's not that big of job, but you are right if you're paying someone to maintain the bike then the krankvent is a good value (assuming it will last for 50,000 miles, because it's not cheap).

But, it wouldn't bother me a bit to swap umbrellas once a year on some wintery day. STILL not trying to defend the stock valves, I'm just saying it's not a deciding factor for me.