Hello all, first post and a new to me 89 Ultra.

History of the bike is unknown, I bought it at an estate sale, non running with 53k on it, carb kit, battery and fuel and she's up and running, Idle set to 1-1.1k RPM.

I understand EVO engines run on the low side for oil pressure and that flow is very important to these engines, more so than pressure


Guage on the fairing shows 25-30 psi cold start, SAE 50w. 90 degree ambient temperature, Same conditions, but HOT/Normal operating temps the guage shows 5 psi Idle, 10-12 at 2500 RPM.

The issue is that the dummy light on the dash is on at idle, barely touch the throttle or raise the RPM to 1200-1300 and it goes off.

I was was under the impression that the dummy light is merely a 2-3psi switch, if the guage on the dash reads 5 psi, it shouldn't be on in theory.

I have not not checked it with a mechanical guage, I hear a little tapping when hot, but it doesn't sound any different than my 1200 sportster.

This oil sender is a two wire sensor, And it's worth noting that the top portion of the sensor (chrome part) has wrench marks and is wiggly.

Any ideas?, guage wrong and light right?, or possibly a bad sender?, makes no difference when I wiggle the sensor.

 

And when you do.... you will know what the problem is.

 

This is the reason the MOCO wants 900-1000 rpm....

Check your pump screen as well.....

 

Screen was clean, idle at 1.1k or so

 

What brand oil are you using?
How old is the oil?
How much fuel contam is in the oil?
Oil pump pressure relief valve stuck?
Oil pickup screen (as someone already noted.)

 

Maybe this will help you.... external oil pressure gauge..

http://www.jpcycles.com/product/5700035

 

If the lifters are not clattering, the oil pressure is high enough.

Raise the idle speed, if that doesn`t eliminate the light at idle, I suggest you replace the sending unit.

 

 

For what it's work my road king would run real slow (800-850rpm) when the efi would screw up and the light never even flickered. I'm with THC and dan89 on the sending unit though

 

Hello everyone I am new here this is my first post I was wondering if the oil pressure switch is a common problem and if that is my problem,I was riding it the there night all gauges looked good when I got home but when I went to start it the next morning and there was no oil light with ign in and when I started it the light came on and I had zero pressure on gauge,I have a new switch ordered and I am hoping that's the problem any info will be greatly appreciated thanks in advance and ride safe hi to hi