Oilpressure warning lamp?

Hello.

According to the former owner of my tracker the bike is equipped with a warninglamp for low oilpressure.

Now the problem is that the lamp doesn´t work. It should glow for a sec when you start up the engine but it don´t. Checked it and it´s not broken!

When reading the manual I ain´t finding any warning lamp for the oil and I´m unsure if the XS is equipped with such lamp?? If so, where do I find the sensor for the pressure??

And by the way......an oil pressure gauge would be much cooler and reliable, right! Anyone having some good advice for that kind of setup??

Thanks/BigBoreSwede

Our bikes did not originally come with oil pressure warning lamps. As I understand it, the reason for this is because the motor has roller, ball and needle bearing throughout instead of conventional friction bearings. These bearings do not require high pressure oil fed to them to make them function, just low pressure oil the lubricate them. As such, the oil pump runs at much lower pressure than what would generally be considered normal, the pressure relief valve being set at 15 psi maximum pressure if i recall correctly. At idle on a warm bike if an oil pressure gauge were set up you might not register any oil pressure, and it would be completely normal for these motors. If equipped with a light it would flicker or possibly stay on at idle, which would unnerve owners who were not familiar with the motors operation, so it didn't get one.

That's what I have come to understand of it from floating around this board and a few others.

Since there is no pressure....that leaves level. People have talked about wanting a good way to check the oil level automatically.

I found these circuits one time. They're similar to what they've used since at least the 80s to measure fluid level in storage tanks. These are miniaturized to measure fluid in a syringe. At least one of them shows how to make the sensor itself (foil on the outside of the syringe). Would be easy to adapt this to a sensor that goes through the filler cap. Instead of measuring you'd use a comparator on the output to turn on an led when the oil got below a certain level. You could use trim pot(s) to customize at what level the led would come on.

http://www.discovercircuits.com/DJ-Circuits/low-value-cap-meter.htm

http://www.discovercircuits.com/S/s-capacitance.htm

Here is the oil pressure gauge setup on my '81/H:



The pickup point for the gauge was originally a hole drilled and tapped in the oil screen cover. It was moved to one of the oil galley plugs on the front of the wet side cover.



The gauge is a Marshal Instruments liquid filed 0 to 20 PSI gauge, and, yes, at idle with the engine hot, it does read zero. The gauge is useful to help determine when it's time to change the oil as the breakdown of the polymers in Multi viscosity oil is evident by a reduction in pressure. The gauge is also useful to keep the pressure low during warm up.