Water Impeller Story and another Question - 1999 115 Merc

[Mscanon99]

Hi All,

Got a new boat a few weeks ago....thanks to all the posters for some great advice....

I took a short test run on a local lake and noted the water temp at 130. Between then and now, finally got some feedback from the original owner though the dealer that the impeller had never been changed...the guys message was that he didn't use the boat that much (170 hrs/8 years) so he didn't bother......?????.....I thought, whoa....8 years...got to get it changed now before my next trip. My local repair shop took care of it the same day and commented that it did not look that bad...I looked at it, never seeing one, thought the same thing, looked pretty good, in one piece and rubbery...went out two days later...water temp now reads about 20 degreas lower at around 110 or so..

So, even though the impeller looked good, it made a difference in the water temp gauge on the dashboard.

Now for the alternater gauge....this thing reads like its a full blast all the time, even after I have charged up the batteries...should this motor be charging like this....in the 16-18 range?

I don't know all the terms and ratings yet, however wondering about the charging. On a battery charger...the needle moves to 0 as the battery is getting charged up. Is there a reason my gauge is pegged to the max? Or it this a potential issue?

Thanks for any advice.

Regards,

Mike

 

[MercFan]

Re: Water Impeller Story and another Question - 1999 115 Merc

Hi Mike,
If your system is an unregulated system like my 70s inline 6 it's kinda normal. On a battery charger the needle moves to 0 because it's an amp guage, the guage on your dash is a voltage guage. The idea being on an unregulated system that the batteries will absorb the extra power. I installed some lights on my boat to take care of the run away voltage. So now when the voltage goes above 14V I flick a switch to turn on one or both of the lights, and that brings my charge voltage down.

Other things I can recommend is to get a bigger battery, or to not charge it all the way to full. If you leave some spare capacity in the battery the charging circuit has somewhere to goes with it's excess power and your voltage reading will be normal 13-14V.

 

[Mscanon99]

Re: Water Impeller Story and another Question - 1999 115 Merc

Thanks for the note...I am going to be going out tommorrow morning in Sea Isle NJ to look for some good Bass spots...

I will try turning on the radio/lights while underway to see what happens to the voltage guage.....

Mike

 

[MercGuy]

Re: Water Impeller Story and another Question - 1999 115 Merc

Your engine should have a regulated voltage supply, and the voltage should not go over 14.5 volts.

I would start by checking your voltage with a voltmeter. No telling how accurate the gage on your dash is. If the volt meter confirms that you are truly running 16 to 18 volts, I would guess that something is wrong. However as noted above, outboards didn't use to have voltage regulators, and 16 - 18 volts is not a big problem, unless you are running some sophisticated electronics.

I don't know enough to advise you on how to diagnose an electrical problem such as that, but I can tell you that the voltage regulator on your engine is a potted module with no adjustments. It's either good, or bad...

-Steve

 

[MercFan]

Re: Water Impeller Story and another Question - 1999 115 Merc

I wouldn't run a radio at over 14V, maybe 15V at a stretch, but this greatly differs from radio to radio though. I just consider a radio a bit expensive to replace if it does blow up in smoke. But certainly play with the lights a bit to keep the voltage under control, or just to run the battery down a bit.

 

[j_martin]

Re: Water Impeller Story and another Question - 1999 115 Merc

I don't know for sure, but I doubt that your engine has a regulator, probably just a 16 amp stator and a rectifier. It could be retrofitted with a regulator off a later engine easily.

I have found that the rectifier only system, when not loaded down with accessories, tend to fry a battery every year or 2. It'll go over voltage when it does.

It helps to keep the water level up faithfully in the battery.

hope it helps
John

 

[MercGuy]

Re: Water Impeller Story and another Question - 1999 115 Merc

It has a regulator. Mercury Part # 815279-3