Mercruiser 5.0 MPI warning beeps

[ulman]

Running at WOT I got two beeps from the warning system. This occured only once. I was trying to trim out just before the the warning, and my first instinc was that the trim out caused it. I have a MercMonitor Smartcraft gauge and I hoped to be able to get some information from that, but there were no alarms on that.

Engine: Mercruiser 5.0 MPI from 2010 with Alpha One gen II

Any ideas ?

Regards
Thomas

 

[oldjeep]

Re: Mercruiser 5.0 MPI warning beeps

Check the level in your drive lube bottle

 

[ulman]

Re: Mercruiser 5.0 MPI warning beeps

Done that. It's full.

Is it possible in any way, that there is lube in the bottle but not enough in the drive?
A couple of month ago the lube was emptied into the bilge by mistake of the mechanic. As there is plenty in the bottle I guesed that new lube was added. Hmmm !

 

[oldjeep]

Re: Mercruiser 5.0 MPI warning beeps

Done that. It's full.

Is it possible in any way, that there is lube in the bottle but not enough in the drive?
A couple of month ago the lube was emptied into the bilge by mistake of the mechanic. As there is plenty in the bottle I guesed that new lube was added. Hmmm !

No, the alarm operates off a float in the bottle.

 

[emilsr]

Re: Mercruiser 5.0 MPI warning beeps

Done that. It's full.

Is it possible in any way, that there is lube in the bottle but not enough in the drive?
A couple of month ago the lube was emptied into the bilge by mistake of the mechanic. As there is plenty in the bottle I guesed that new lube was added. Hmmm !

Without knowing all the details it's hard to say.....but.....

Yes, that's possible. The lube must be filled from the bottom up; meaning if the lube got emptied from the drive and then the "leak" immediately fixed it MAY not have run out of the bottle. The sensor is in the bottle though so am thinking that probably isn't it. Still might not be a bad idea to change your drive lube just to be on the safe side. For the cost of 2 quarts of drive lube you'll have piece of mind there.

If it only beeped once I'm stumped. When it goes to "soft" guardian mode you get a beep every 2 minutes (IAC valve is a likely culprit here), and that beep every 2 minutes repeats itself until the code is cleared. Have it scanned and that'll tell you if there is an error message stored in the computer.

Low water pressure maybe? Were you trimming out in rough water?

 

[ulman]

Re: Mercruiser 5.0 MPI warning beeps

No, not rough water.
I was testing a new propeller and it was first time at wot.
I'm not shure about the RPM, but one guess could be something related to that.
The MercMonitor records RPM at max speed, and it says 3150 RPM at 40 MPH.
Well the engine has a max range about 4600-5000 RPM so I don't think the smartcraft got that measured correctly.

 

[emilsr]

Re: Mercruiser 5.0 MPI warning beeps

I'd have it scanned; just for the piece of mind. Might be nothing. Hope so.

 

[ulman]

Re: Mercruiser 5.0 MPI warning beeps

Well, I bought the Diacom tool from Rinda Technologies.
I have a couple of alarms in the ECM history.
Horn output
Low drive lube
ECT overheat
Overspeed

It must be the overspeed alarm. It makes sence and the 'Run Time' seems right. RPM is 5155. I use a 15" propeller and maybe ought to try a 17" or even higher.

By the way: The horn output alarm has been going on since the engine was installed !

 

[Don S]

Re: Mercruiser 5.0 MPI warning beeps

By the way: The horn output alarm has been going on since the engine was installed !

Then maybe it's time to get it propped correctly. The prop is what sets your max WOT rpm, not the ECM or Smartcraft. The ECM does have a rev limiter to keep you from going over the max rpm it's set for. (Usually 5100 rpm for an engine with max rpm range of 5000).

You say the engine was from 2010, what was in it before?

 

[ulman]

Re: Mercruiser 5.0 MPI warning beeps

Then maybe it's time to get it propped correctly. The prop is what sets your max WOT rpm, not the ECM or Smartcraft. The ECM does have a rev limiter to keep you from going over the max rpm it's set for. (Usually 5100 rpm for an engine with max rpm range of 5000).

You say the engine was from 2010, what was in it before?

Before I had a Merc 5.0 carb with 220HP with Alpha one gen. 1 and the same gear ratio. I was told that if the gear ratio was the same, I should not change propeller.

The current prop is 15".
Gear ratio 1.62:1
Sea Ray 220 Sundancer from 1989
Dry weight 4100 pound

 

[Don S]

Re: Mercruiser 5.0 MPI warning beeps

No wonder you have problems. You should be running a 1.50 gear ratio with the MPI engine, and then probably a 19 to 21" prop. Not some dinky little 15" prop.

 

[ulman]

Re: Mercruiser 5.0 MPI warning beeps

I was told by the mechanic that gear ratio is 1.62. I bought a package mercruiser 5.0 mpi FWC alpha one. Is it possible to tell the gear ratio by the serial no. ?

 

[Don S]

Re: Mercruiser 5.0 MPI warning beeps

Did you replace the outdrive too? Or just the engine. Yes, I can tell from the sn what the ratio is. Engine serial number also.

 

[ulman]

Re: Mercruiser 5.0 MPI warning beeps

Yes, new engine, outdrive and transom. Outdrive sn is 1A281842

 

[Don S]

Re: Mercruiser 5.0 MPI warning beeps

Then you just need to get it propped to get the proper WOT rpm.

 

[ulman]

Re: Mercruiser 5.0 MPI warning beeps

Thanks. Can you tell the gear ratio from the sn 1A281842 ?

 

[Don S]

Re: Mercruiser 5.0 MPI warning beeps

It's 1.62 like your mechanic told you. Should be stamped in the port side of the drive.

Just noticed you boat ia 4100 lbs, so that ratio is fine.

Post a question over in the prop forum, and read the stickies on the info you need and get the right prop. You will find that boat does a lot of things better than it will with that 15" prop on it.

 

[ulman]

Re: Mercruiser 5.0 MPI warning beeps

Great. Thanks - i will post a question in the prop forum