Airhead oil temp gauge

Anyone have an oil temp gauge on their airhead? I have an '89 R100GS. I'd like to be able to keep an eye on the oil temperature. I can't use the dipstick type analog gauge because I have the big HPN gas tank. I seached the airheads.org archive but didn't see any advice.

Aerostitch has one here that looks pretty good.

It works by replacing the oil drain plug. They have three sizes available: 12mm x 1.5, 14mm x 1.25 and 14mm x 1.50. any idea which, if any, of those would fit an airhead? I can measure the mm, but I don't have a pitch gauge.

Thanks, Scott

I personally wouldn't do it.

Had a Luftmeister one on my (now in Massachusetts) '94 GS. The readings'll scare you! Dude at Aspen Motorrad in Flagstaff took it out and threatened to throw it far across the lot when I aksed him about the "high" temps...he GAVE me a brand new stocker. I sold the temp guage one on Ebay soon after.

I have a VDO gauge mounted on my 83 R100RS. I drilled & threaded a hole in the side of the oil pan. I also have an oil pressure gauge and like having both.

Way to go. I like it. Oil temp gauges have received bad mouthing for too long. If you want it then get it. I think this is the way to go.

I wouldn't do half the shit I do if I had an oil temp gauge.

For me what am I going to do with the info a temp gauge gives me? I have a sump extension and an oil cooler, if the oil gets too hot (what is that number?) what could be causing it (other than obvious clogged fins or cooler) and what am I going to do about it? Local temps this week are 32-41C, the oil is going to get hot in those conditions. Regular oil changes with appropriate rating, good quality oil and forget about it.

Curious, what were the "high" temps you were seeing? I had a Luftmeister dip stick on my R100RS back in the day. I seem to remember it staying in the 200 to 220 degree range...

If you are running an oil cooler than the temp guage will be useful telling you when the oil is still too cold to run the engine hard

I have a NewSouth Indigo oil temp gauge on my 92 RS. I have it and the matching voltmeter in the fairing cutouts. I bought the voltmeter because it is a 270 degree sweep and I can read to tentths. I bought the NewSouth oil temp gauge because it matched the voltmeter. I drilled and tapped the side of the oil pan for the sending unit. I would not care for the sending unit in the drain plug.

Mine has a Motorren Israel thermostat and holds temp well, but it runs up some in stop and go driving or when drafting on the interstate. It is amazing how long it takes for the temp to come up. It has caused me to ride gently longer before thrashing it.

Back in the my earliest airhead days of thrashing my Porsche 912, I had a pair of head temp gauges with probes that went between the spark plug and head. The air cooling on a Porsche flat 4 is somewhat asymmetrical due to the oil cooler in the cylinder shrouding, whose bright idea was it to cool the left side with air heated by the oil cooler? First thing I did was remote the cooler. Back on point, a pair of head temp gauges were useful and interesting in that application. On our bikes, one should be adequate.

Knowing the oil temp is useful in allowing the bike to fully warm before hitting it hard, knowing the head temp is useful in saving the valves, heads and pistons particularly if using dubious gas. It's been a long while but the senders and gauges probably came from a national supplier called P.B. Tweeks, haven't done business with them in a quarter century so I don't know if they are even still in business.

I went "full stupid" mode and put a set of EGT probes on my R1150. I guess it's just nerd fun to hook up a bunch of gages on one like it was an ICU patient. "Ignorance is Bliss" mode has much to recommend it as well. I have finally decided that I am just going to run the bitch until it quits anyway. Then I will fix it. Monitoring voltage is an Airhead necessity. Everything else is pretty much for amusement or to feed the worry mill.

I have a Trailtech digital dash that displays temperature. I used a spark plug mounted sensor for head temp monitoring on my '79 while I ran that gauge setup. It was very informative about the huge swings in temp an air cooled engine goes through, but other than confirming what I already knew, was not particularly useful nor did it alter my operation of the bike.

An oil temperature gauge would scare me - by telling me how cold the oil was on my winter commutes.

I ride every day to work and now in winter where I live it gets down to low 30's so every morning I like to ride until the oil temp reaches at least 210. That way it helps to burn off any condensation that may have formed overnight.
The only time it will not get there is when it is raining then it only gets to about 180. In the summer I have seen it go up to 300 when on a dirt road in the mountains when it was about 100 outside. Yes you can ride an RS on dirt :)

Don't forget sand, yez can ride them on sand too.

This might appeal to someone who wanted to use a temp gauge - http://www.ebay.com.au/itm/BMW-R100...461364?hash=item4d53cd8bb4:g:ZWEAAOSwImRYmqa4

These engines have been running without a temp guage since the beginning of the last century..the RT and RS finally got coolers when the fairings cut the air flow..GS got one for whatever reason and then they stuck it on the right crash bar where it almost always leaked if you happened to drop the bike on that side..and you learned to carry a block off plate in case that happened (still have 4 of them).

These engines have gone around the world, across the Darian Gap, and just about every road on the planet without a gauge..just change the oil and filter like a good owner should and enjoy the ride.

Yeesh - except for the crud in the pan. Did he bake a lasagna in that thing before he posted it for sale???

The stock oil cooler is actually self regulating - Rob Farmer posted images on the UKGS with a thermal imaging camera which demonstrated the process, but simply oil changes viscosity with thickness and will always take the line of least resistance, so it only flows through the hot portion of the cooler.

The GS had a cooler because it had the smallest sump ever fitted to an Airhead, a silly sump guard which does little more than shield the sump from cooling air, and could reasonably be expected to see a bit more slow speed high rev work.

Oil oxidizes when it starts to get too hot, and the process speeds up once you get past 120C. The point it starts to break down depends on the oil , some Dino around 140C, Synth usually around 20 degrees more.

But if you are running around 120/130C most oils will oxidize quickly and be as black as molasses in as little as 500km.

There was a thread a while back regarding blown airhead motors and the general consensus was that virtually all failures had been caused by oil failure of some sort, usually overheating.I think Beemerguru was of that opinion then --------------.

I have a dipstick oil temp gauge and a oil pressure gauge on my G/S, the oil pressure is more useful as it is easier to read than the dip stick gauge, and confirms that as the oil starts to get past 100 C the oil pressure drops pretty quickly.
And I am running a 10/60 full synth Motul !

I usually include a bit dirt road in my daily run, and as the temp was 47C in the shade today the motor and oil was reasonably hot and the oil pressure down when I arrived home, so I see some benefit from having them, others in cooler climes who do little to no dirt might not. The motor has gone 430,000 km on the original crank and main bearings, so again the pressure loss might not be typical , but it is real on my bike, which is what matters too me!
Worth remembering too the most oil warning light senders are set somewhere between 3 and 7 PSI , so all they will tell you is that you have just blown your motor!