Totally intermittent alarm 5.0 Mercruiser Alpha 1 drive...

[Wild0409]

I recently bought a 2003 21 foot Bayliner model 2152 Cuddy with a 305 Chev (5.0 liter) Mercruiser coupled to a Merc Alpha 1 outdrive. I took 'er out for my first run, and over the roughly 3 hours of operation, several times the alarm would just go off completely intermittently... Like, "Beep... Beep... Beeeeeeeeeeep... Beep... Bip... Beeeeeeep..." and so on for 20 to 40 seconds or so, then it would go away for awhile. This occurred at 40 mph cruise, not top speed (52 mph). It was a little choppy out on Puget Sound, banging around a bit, but nothing out of the ordinary. Oil pressure was good, over 40, Temp was good, 'round 180, gear lube reservoir for drive was right up to the top... What else causes that damn thing to go off? Any experience out there with this? Ideas?

 

[alldodge]

I recently bought a 2003 21 foot Bayliner model 2152 Cuddy with a 305 Chev (5.0 liter) Mercruiser coupled to a Merc Alpha 1 outdrive. I took 'er out for my first run, and over the roughly 3 hours of operation, several times the alarm would just go off completely intermittently... Like, "Beep... Beep... Beeeeeeeeeeep... Beep... Bip... Beeeeeeep..." and so on for 20 to 40 seconds or so, then it would go away for awhile. This occurred at 40 mph cruise, not top speed (52 mph). It was a little choppy out on Puget Sound, banging around a bit, but nothing out of the ordinary. Oil pressure was good, over 40, Temp was good, 'round 180, gear lube reservoir for drive was right up to the top... What else causes that damn thing to go off? Any experience out there with this? Ideas?

:welcome: to iboats

There can be a few things which can cause the alarm to go off, even a bad connection. Low battery voltage, bad ground but in most cases it turns out to be the water pressure sensor. Your sensor will be on the top rear of the engine which is attached to the power steering cooler.

 

[Fun Times]

Hi there Wild0409, welcome to iboats! You'll need to clarify if the engine is MPI or carbureted?

 

[Four Winns Fanatic]

I had exactly same issue with 5.0 l carbed tks 2007 Mercruiser turned out I had over tightened the threaded battery posts they were 1 " long hex stainless bolt on top of battery in a lead like base and over time my turning a hex nut to tighten eventually pulled the positive bolt off the base and it was loose and as I throttled up past 2600 rpm or so to 3700 it would intermittently or sometimes give steady alarm.I got some terminal adapters for large round posts and problem seems solved.Not sure if you are using the threaded post .In any event I found connections are very important.

 

[Wild0409]

It is carbureted.. 2 barrel. I took it out for a long run today, went through over a full tank of gas, about 5-6 hours of run time, and it only went off a few times. It occurred when I started hitting some chop and throttled it back from about 40 to 36 or so. As soon as I bumped it back up to 40 (around 3100 rpm), it went away. And it wasn't as annoying this time. Just a few short beeps. Every gauge was right-on perfect, and other than that, it ran like a top. I will definitely check out that water sensor though. My batteries and the connections are good, tip-top. Made sure of that before I took it out for my maiden voyage... Thank you all so much for your help! Bill

 

[Fun Times]

It is carbureted.. 2 barrel. I will definitely check out that water sensor though.

Since your engine is carbureted, your engine model won't have the water pressure sensor, that's for fuel injected engines only. Even tough you may not see it on the gauges, the five things that could sound the warning horn on your engine model is, engine over temp due to it being a different sensor than the gauge, low oil pressure being under 4 psi...(< again different sensor), Gear/drive lube reservoir mounted on the engine, weak 12 volt power supply do to a bad/loose wire/battery connection somewhere basically turning on and off the ignition power super quick especially when going over rough waters, the Tan/blue warning horn wire is shorting to ground someplace intermittently.

It only went off a few times. It occurred when I started hitting some chop.

Which may indicate a loose power wire/cable connection somewhere.
http://forums.iboats.com/forum/engi...nes-outdrives/7719058-coolant-temp-sender-bad

Throttled it back from about 40 to 36 or so. As soon as I bumped it back up to 40 (around 3100 rpm)

What is the max RPM you're able to achieve when you are full throttle with a little bit of trim on the stern drive? Just want to be sure your tachometer is working/adjusted correctly. Your RPM to speed numbers don't seem typical.

 

[Wild0409]

Since your engine is carbureted, your engine model won't have the water pressure sensor, that's for fuel injected engines only. Even tough you may not see it on the gauges, the five things that could sound the warning horn on your engine model is, engine over temp due to it being a different sensor than the gauge, low oil pressure being under 4 psi...(< again different sensor), Gear/drive lube reservoir mounted on the engine, weak 12 volt power supply do to a bad/loose wire/battery connection somewhere basically turning on and off the ignition power super quick especially when going over rough waters, the Tan/blue warning horn wire is shorting to ground someplace intermittently.


Which may indicate a loose power wire/cable connection somewhere.
http://forums.iboats.com/forum/engin...emp-sender-bad

What is the max RPM you're able to achieve when you are full throttle with a little bit of trim on the stern drive? Just want to be sure your tachometer is working/adjusted correctly. Your RPM to speed numbers don't seem typical.

I will pay close attention the next time I take it out and get back with you. But yeah, at 3100 RPM, I was running 39-40 mph, GPS and gauge agreed and were right on... I'm pretty sure I had it trimmed up good, up just to fingertip steering... It does have a stainless prop that is not OEM, and I really haven't looked into it's pitch or anything, pretty much just assumed whoever replaced it did some homework (probably never wise to "assume" I guess)... I know I'm not exactly overwhelmed with it's hole-shot, and would like a little more torque to stand it up when I punch it... This will be more of a concern when I hit the fresh water to do some water skiing and whatnot... I'm thinking about dropping it off at Performance Marine in Everett for a professional opinion... and to give it a once-over...

Oh, and here's another question....

I left Everett, Washington, did a loop-around of Lopez and Blakely Islands in the San Juan's and back to Everett, about a 6 hour cruise, 5+ hours at cruise speed, and burnt 26 gallons of gas... Is that normal? Seems excessive to me.