150 XR6

[moetorola]

Have an 150XR6 2000 0t149393

Update: It appears this whine sound starts to occur after a run. It does not do it when started up, or after fishing awhile. After a run the sound is there and slowly starts to quite down letting it idle, now I am worried it might be an upper bearing. I could not pinpoint the location of the sound.
The reason why I think that it could be a possible bearing, I was checking all the bleed lines with a syringe and found the bottom bearing bleed port is a check valve and works in the correct direction. But the upper bearing port is NOT a check valve it is pass thru either way. It appears the upper should be a check valve according to the manual. So either the check valve has failed or my manual is incorrect (not a OEM Merc manual).
The bleed line hose is hooked from lower to upper bearing ports, which should be correct.

From post last year
It has a slight whine sound, similar to a gear sound. I don't believe it is the lower unit. I still hear the sound idling in neutral.
I do not here the sound while on pad, but likely cant here it because the engine drowns the sound out at higher RPMS. The pitch of the sound does increase as RPM goes up.

Interestingly, I do not seem to notice it when first started for the day.

My first thought that possibly oil pump gear. It does have the metal gear, but I have heard the crank gear is still plastic.

I already have an oil pump delete kit, but prefer to keep it oil injected (more convenient).

I don't recall hearing this sound in the past.


Thoughts, other things to check!

Thanks in advance!

[moetorola]

One side note: Could the flywheel be rubbing on the stator if it is expanding ever so slightly from charging load after a high speed run. The battery is about a year old, but I did get an overvoltage alarm during my last outings after first started.
Guess I could pull flywheel to check for any rub marks, definitely easy to do I have the merc lift ring, flywheel puller combo.

[EuropeanAM]

I'd pull the flywheel and inspect. A loose flywheel could rub on the stator...

That top fitting SHOULD be a check valve. At the very least, replace it now. It may be too little too late, but you'll have a better chance with it functioning correctly.

Keep in mind- the check valve may have failed due to metal in it... one possible reason it doesn't work properly.

XR6 doesn't have an "overvoltage alarm". It has a SOLID beep (overheat), Fast Beeping (Oil Pump Rotation Problem), or Four Beeps, Pause, Four Beeps (low oil level).

The "Plastic or Metal Gear" you read about is the crankshaft (DRIVE) gear. Yours would be nylon. Driven gear is metal.

[moetorola]

I'd pull the flywheel and inspect. A loose flywheel could rub on the stator...

That top fitting SHOULD be a check valve. At the very least, replace it now. It may be too little too late, but you'll have a better chance with it functioning correctly.

Keep in mind- the check valve may have failed due to metal in it... one possible reason it doesn't work properly.

XR6 doesn't have an "overvoltage alarm". It has a SOLID beep (overheat), Fast Beeping (Oil Pump Rotation Problem), or Four Beeps, Pause, Four Beeps (low oil level).

The "Plastic or Metal Gear" you read about is the crankshaft (DRIVE) gear. Yours would be nylon. Driven gear is metal.

Thanks Don,,, Do you have a part number for the check valve so I can give your parts a call?

Also, how do you change it, just pull it out?

As far as the overvoltage, let me clarify.. it was an alarm on my Lowrance graph, it is set to trip at 15volts. So with voltage drop I figure it was around 16 or so volts, and then went back to normal.

[moetorola]

One other thing, is it possible to change the bearing with out splitting the block??

[moetorola]

update: went home and checked the bearing check valves since it had been maybe 2 years when I checked them and when I thought I had the problem with the upper bearing check valve. The check valves are working correctly testing with a syringe. I was able to pull a tiny amount of what appeared to be fuel oil mix from the bottom bearing. I tried to pull oil from the top bearing port, but the check valve is working and could not pull any oil from it to check for any metal shavings. I was able to push air into to it, so the valve is checking correctly as is the bottom bearing check valve.

So now going to remove flywheel to check.

Is it ok to use an impact to remove the flywheel nut? And any tips on removing and reinstalling the fly wheel?

I will also inspect the oil pump gear with a bore scope. Since the sound is more of a wuring sound and not what I would think a sound a stator touching on flywheel would make more of a ticking sound, this is more of a continuous sound that varies with rpm and possible heat related.
It sort of reminds me of a power steering pump low on fluid on a car, but not as loud.

[JOE54]

id pull that one apart MOE

[moetorola]

id pull that one apart MOE

Not what I wanted to hear..LOL

Side note, I pulled of that bleeder bearing hose from top bearing and bottom and top check valves are for sure working with engine cranking sucking at the top and blowing from the bottom.

I pulled the oil pump and inspected crank gear, looks great no sign of being worn.

I still need to pull the flywheel to inspect.

Next time out, I will use a mechanics stethoscope and see if I can pinpoint the location. And also get some audio if the camera will pick it up.

Thanks JOE and DON!!

[JOE54]

yea man

[moetorola]

Flywheel off.
Thoughts??

[moetorola]

Got a recording of the sound.
Could possibly be the lower unit. Seems the sound goes away when in gear. Also the sound seems to change when trimmed up. The sound does eventually go away idling.

[moetorola]

This vid you can hear it better. Seems you can here it better on a cell phone.
At 15sec I put it in gear and sound goes away, at 18sec I put back in neutral but takes until 30seconds or so before sounds starts coming back.

[EuropeanAM]

Hard to diagnose sounds by keyboard and monitor... I honestly didn't hear it.

As for the top bearing- the recommended method is to split the crankcase open.