1998 Yamaha Pro V 150 Question

[thorshammer]

I recently purchased a used boat which had a 1998 Yamaha Pro V 150 on it. The boat ran fine for a while. Yesterday it started off running fine. My last stop fishing was about 1.5 miles from where I placed the boat in the water.

As I tried to come back on plane the motor would not get over 2000 RPMs and an audible alarm started sounding. The motor ran perfectly until it reached 2000 RPMs and would start to sputter and the alarm would sound.

I had to make the 1.5 mile run at about 4 miles an hour back to the ramp. I stopped several times to allow the motor time to "rest" but that did not help. It repeated the low RPM each tme i tried to get under way.

Any ideas on what might cause this?

[boscoe99]

Low oil quantity in the main oil tank or over temperature will set the alarm.

[rodbolt17]

by main tank Boscoe means the engine tank.
low battery voltage will do it as well.

[thorshammer]

1998 Yamaha Pro V 150

It was the small oil tank mounted in the motor housing. The oil level had fallen enough to kick the alarms. I noticed an "emergency" toggle switch mounted near the small oil tank. I flipped the toggle and the small tank filled back up. All alarms immediately stopped when it was about 1/2 full. Took it for a water test and it ran fine.

Now I just have to figure out why the large oil tank did not the fill the small tank.

[boscoe99]

The remote boat mounted tank has a sensor in it. The sensor consists of a float activated switch that is closed when the float is up and open when the float is down.

If the switch is open then automatic transfer of oil from the remote tank to the main tank will cease. This is normally the situation if the remote tank is simply low on oil.

If the remote tank is full of oil then the switch failing in an open condition, a broken wire, corrosion in terminals or a faulty ground to the switch will result in the CDI thinking that the switch is open, in which case it will not allow the automatic transfer of oil.

Ground is from the block to the switch via a harness, across the switch and then to the harness and then on to the CDI. Anywhere along that path there could be a problem that prevents the ground reference from making its way to the CDI.

Start with checking this out first. Let us know what you find. Good luck. There are other things that can result in a failure of the automatic transfer to work but let's start with the most likely stuff first.