A few questions.
I have the stock 103" engine and I use the HD temp. guage dipstick. Assuming it is accurate, and it appears to be (reads in the 240's to 250's with hot engine when the air temp. is in the eighties to ninety; today air temp. was around 60 degrees and it read 225 degrees), my question is, isn't the guage is reading the temp. in the oil pan? And how does this compare with the temp. in the crankcase which I suspect would be hotter, but I do not know by how much? Does anyone here know? And does it matter? I think the "hard wire" HD temp. guage sensor connects in the bottom of the oil pan and I would think it reads the same temp. as the dipstick guage. Is that right?

 

Today I came back fro seaside heights and I was running about 240. Normally she runs 260 ish.....the outside temp does play a factor.

 

240 to 280 is the normal temperature for the 96" during the Arizona summers.....

 

I have a 09rg with a 96" and it runs about 230ish on a 80degree day. Buddy has a 110 cvo rg that runs much hotter. Definitely air temp can affect the temp of the oil.

 

Just ride the damn thing. If it's to hot to sit on, pull over and take a break.
Oh yeah, use synthic oil, these things run HOT.

 

To answer one of your questions-your dipstick temp gauge is reading the oil temp in the oil tank, the dash mounted oil temp gauge is wired to a sensor at the bottom of the engine and it will read hotter by 10-20 degrees.

 

I have checked two HD Dipstick Temperature Gauges (the first one eventually acquired some moisture internally which the dealer replaced) against an electronic immersion thermocouple and dang if they weren't both spot on! What a shock!

I have a HD Oil Cooler on the bike and never see anything over 250*F (usually 190*F - 220*F) even in 110*F+ ambient air temperatures. Because we can split lanes here in California I'm not sure what it would do if I actually got stopped in traffic for an extended period of time.

 

The digital temp guages are very accurate when it comes to measuring temps but I have had two that do not measure the fill level accurately.

Actually, the hottest oil temp is the return oil that is in the tank. The temp of the oil measured at the bottom of the pan should be about the same; it won't cool much from the tank, throught the baffle and down to the bottom of the pan. The tank guage and the dash guage should be pretty close to one another.

Since the motor is air cooled, obviously the ambient temps have an effect on the oil temperature. That is why an oil cooler will help. IMHO, 250* is as high as I am comfortable with and 235*-240* is about right. If the oil temps see more than 250* very often, the change interval should be 2500-3000 miles instead of 5000 miles. Another reason why I prefer conventional oil over synthetic; I change every 2500-3000 miles.

 

If you follow the posts on here and the advice from my parts guy at Bergen Harley, the dipstick gauge is one of the most complained about accessories they sell.
I suppose they work when new but many people have had them fail or lose any worthwhile accuracy.
My parts guy said they're great for people who like to keep their bikes in perfect condition by never riding them.
I woulden't place a whole lot of faith in their performance.

 

A pot of boiling water is pretty much dead on at 212F, assuming you are not too far from sea level.

Just check it versus the boiling water once a year, good to go.

Mine is spot on.