I'm chasing the problem of my oil light flickering on my 2000 RKCi and this weekend I am gonna start with replacing the oil pressure sending unit/switch and at the same time I will attach a gauge to check the pressure. What should my pressure be at cold idle and then at operating temp 2000 rpm?

Anything else I should know about when checking the pressure?

Thanks

 

Did you check to see what the level was/is of your oil?
That would be my first step.
That lil gauge will drive you nutz !
First it will be high when cold(30-35psi) and then when hot
it will read dam near zero when at idle.
I am sure there will be someone with more experience than I to
add to this thread and offer you more insight.
Rob

 

Cold pressure will be your ( generally ) highest reading around 44 psi ... At operating temperature ( riding down the road ) you should see @ 28 to 32 psi ... At idle ( especially on a warm day ) it will read real low ( 2 to 3 psi ) .... Don't forget that these engines all use roller bearings in the lower end not flat bearing as in most automotive applications.

 

Oil pressure will vary depending on the condition of the engine. It is not uncommon for the oil light to blink at idle on the early models. Could be the result of sending unit going t!tsup, could be lifters bleeding down, could be worn oil pump, etc.

First step would be to check pressure as you have planned; you need the baseline at idle and say 3000rpms at operating temperature.

If pressure checks out, a new sending unit might solve the light issue but, if not, a Baisley pressure relief spring will definitely help oil pressure at idle. The spring is $12 and it works.

You didn't mention how many miles on the motor. You also need to remember that the H-D lubrication system is based on volume, not pressure.

 

Oil level has almost nothing to do with pressure, I hear it all of the time on this forum. The engine itself doesn't have a sump in a pan like a car motor, so you could almost run 1 qt , and the pressure would be fine.
Your cold psi should be around 40 , and warm going at 55mph should be at around 30, and it will scare you at idle warm, but if the oil pump is good, don't worry about it unless the oil light comes on, and pressure reads 0, it will probably read 2-3 pounds.

 

Yep Rob - Oil level is good - hoping blinking is either a bad sending unit or a short and not an f'd up pump and no engine damage.

Thanks Larry

Thanks djl - bike has about 47500 miles on it. I will look into that spring you mention.


Thanks Bill.

 

Old rule of thumb...

If the gauge moves off the peg when it's idling hot, you're good.

 

... This pretty much sums it up as far as pressure at idle is concerned !

 

Before I did my camplate and pump upgrade, my hot idle pressure was maybe 3-5. 2500 rpm at op temp, I was right around 30. Cold idle about 25, cold 2500 rpm, about 45.

Now, hot idle 10-12, hot 2500 rpm 35-40. Cold idle 35, cold 2500 about 45.

I have to believe that the relief valve is set right around 45 because nothing will cause it to go over that.