I have one that works:

Look up where the oil fill plug is

I use a $5 kitchen thermometer, works just fine.

It's just held by a couple of turns of tight wire
there on the cooling fin.

The long needle reaches about until where the
spark plug is, so it measures the case/chamber's
temp, not necessarily the oil temp, but it does work
& fluctuates a lot under different driving conditions.

i.e.
cold start = current temp for your area
normal/road/hwy = 150-180fh
traffic/high speed/stress = 190-210fh

C'ya!

Wife is gonna wonder where her thermometer went. What is normal running temp? Poultry, Well done Beef or Pork.  

Glad you'all like the idea, I REALLY like that other German
oil-temp gauge, but at $5dlls Vs. $50 I keep this one.


...anyway, DOES ANYONE REMEMBER WHERE those
thermal savage engine pics are?  remeber those?
(I cannot find them anywhere)

Someone posted about a year ago some thermal-camera
photos taken from a working savage engine that showed  
exactly where the hottest areas of the case were and these
illustrate beautifully at what temp and how this engine works.  

i thought abot the thermoter,not long tho got the german gauge two birthdays ago..
i live in the high desert of western colorado dont need to be looking for a stop lite to tead the oil temp...
highest reading to was summer b4 last 60+ mile run back home 65mph hwy never exceded safe zone  60>120C  (108>250F)
hit 100C at a stop light w/ambient of 212C  (140F/100F)
somebody check the math..
i like watch the temp as i ride these ol eyes dont want to be lookin down by my right ankle @ 65mph!!!