VRO Pump trouble??

I have a 1987 Evinrude 50HP. The previous owner has changed the original VRO to the newer version with the alarm approx 3-4 years ago. When I go out for a leisurely ride at Idle speed, or slightly above, I get the low oil delivery beep after about 5 minutes or so. ( The beeping on and off every second or so ) I have also had the engine speed slow down as if it is running out of fuel with and there is no alarm. If I open the throttle at this point, the engine will bog, but eventually pick up and run at high RPM properly. If I open the throttle when the beeping starts, the engine will pick up, and the beeping will stop, and all appears to run properly.

I have checked all hoses and clamps. The Clamps have been replaced with the proper manufacturer replacement ratchet style ones.

I have changed the spark plugs, I had first thought the bogging down was caused by fouled plugs, this was before I started getting the low oil flow alarm, but the old plugs looked good, and were replaced anyway.

I suspect that maybe I have a problem with the air motor part of the VRO pump that maybe its not pumping properly at low RPM. Possibly an air leak in the diaphragm, or check valves. When the engine RPM is increased, the pressure from the crankcase can overcome the leak in the diaphragm of the pump, and then it can pump fuel, and oil properly.

Is there a way to test the pump? Is there a rebuild kit available? I don't have a problem spending the money on a new VRO pump if needed, but I'd like to be sure it's faulty first. Is it possible that the pulses from the Crankcase are to weak at low RPM to run the pump properly? Is there a way to test this? I have the old pump that I can disassemble to use parts if they are compatible.

Sorry for the long winded post, but I thought I'd give all the things that I have tried so far. Thanks in Advance.

Alan

Re: VRO Pump trouble??

Here is a question for you, pull the cover at idle how often does it click?
Every few sec.? once a sec? ever 10 sec?

Re: VRO Pump trouble??

karlow1 said:

Here is a question for you, pull the cover at idle how often does it click?
Every few sec.? once a sec? ever 10 sec?

Click to expand...

I agree karlow1. That is the best way to check pump.

Re: VRO Pump trouble??

lavander said:

I have a 1987 Evinrude 50HP. The previous owner has changed the original VRO to the newer version with the alarm approx 3-4 years ago. When I go out for a leisurely ride at Idle speed, or slightly above, I get the low oil delivery beep after about 5 minutes or so. ( The beeping on and off every second or so ) ...

Click to expand...

Alan: The beep every second or so is "No Oil" not "Low Oil". The difference is that Low oil is a sensor in the oil tank which goes off when the tank gets low. The engine is still getting oil through the fuel pump, but it's reminding you to re-fill the tank in the near future. Not critical to deal with it immediately, but soon.

The No Oil sensor is at the fuel pump and indicates the engine is not getting oil through the fuel pump. A more serious condition requiring immediate action to either correct the problem or put oil directly into the gasoline. Big differnce - not only in terms of how serious, but also in determining where the signal is coming from to troubleshoot. If you're uncertain about the alarm codes, you should get the yellow sticker that is available and stick it on your dashboard like I did

Your problem is probably in the oil side of the fuel pump, the sensor, or the route of the oil from the oil tank to the fuel pump (pickup/filter, hoses, clamps).

karlow1 said:

Here is a question for you, pull the cover at idle how often does it click?
Every few sec.? once a sec? ever 10 sec?

Click to expand...

Karlow: is this click clearly audible over the sound of the engine idling? Mine is VERY loud when idling on the hose and I'm wondering if I could even distinguish a click coming from the fuel pump. How often SHOULD it click at idle - your comment didn't mention what would be normal. Thanks.

Re: VRO Pump trouble??

And by the way, welcome to iboats.

Re: VRO Pump trouble??

Karlow1
I will check the pump at idle this weekend. I don't have the boat here at home, it's out at camp. Is the click noise made every time the pump is delivering oil?

dajohnson53
I know the alarm that I have is that the pump is not delivering oil, I guess in my original post I wasn't clear on that. I understand the beep every 20 seconds to be low oil in the reservoir, and the contant beep to be the engine overheating. Is this correct?

Thanks for the tips and I will check for clicking of the pump and how often.