Volt meter gauge pegging at 18V

I'm finished with the restoration of my '83 Ski Nautique 2001!! Everything seems fine, but i really don't know for sure how smooth it should run, top speed, etc.   If someone could please help me answer a few questions, it would be much appreciated.

First, my new gauges are great, but the volt gauge show's mid 12v -ignition on - not started. When started, it is pegged at 18v.
I purchased a new alternator. Meter reads 14 - 15.8v when running at the alternator and also battery.
The "i" terminal on the Volt Meter is hooked to a lead from the "IGN" terminal from the ignition switch. (purple wire) - Alternator (orange wire) to the "S" and black ground wire to the "G" on the Volt Meter.
The wiring diagram I copied off this site, shows the battery (red wire) hooked directly to the "I" on the back of the volt gauge, not the purple wire lead off the "IGN" as above. If I switch that wire to the "bat" (red wire) on the ignition switch, it still reads 12v, but it will always stay on, regardless of the position of the ignition switch. Makes sense i guess, as it is directly tied to the battery. Is this normal for the volt gauge to stay on?

Not sure yet if this will correct it pegging to 18v when running, but I thought since the purple wire comes from the coil, maybe this is why the volt meter is pegging. (I converted to EI, so the resistor is within the Flame Thrower Coil).

2ND question:   I have a 351W engine, reverse rotation, standard heads, holley 4bbl carb. After about 10 hours it's top speed is about 42 to 43 mph on medium rough water.   Is that about right? I've seen others boasting of 50 to 55 mph, but wasn't sure if that was GT40 heads, etc.
Final question: I have a new propeller. There was no foam replaced in the floor, just stringers and glass. I notice some vibration from about 20 up to 43 mph, but not bad.   It seems more to be related to having a 351 engine roaring in the middle of the boat. So, maybe the foam dampens the noise/vibration a bit?I

Thanks for any thoughts.

Bit of a confusing post, but if you have 15 volts at both the battery and the charging wire from the alternator,when the boat is running, there's no way you can increase the voltage from there unless you have some kind of electrical magic going on

If you had say 20 volts or so, from the alternator,that would be a different story.

Why don't you take your multimeter and check voltage at the back of the installed voltmeter and see what it says

That should tell you the installed voltmeter is reading wrong.

Edit see my post below this one about your s terminal.

As far as your speed, info like RPM and prop brand and size and whether you're using GPS would be helpful to know too

KENO wrote: Nothing gets hooked to the s terminal on the voltmeter. Nothing at all .

Ken,
What would the intended purpose of a "S" terminal be on a volt meter?

8122pbrainard wrote: KENO wrote: Nothing gets hooked to the s terminal on the voltmeter. Nothing at all . Ken, What would the intended purpose of a "S" terminal be on a volt meter?

It's there to confuse people

When the manufacturer uses the same housing for something like a fuel gauge, oil pressure gauge or water temp gauge that has a sending unit it's used for that incoming signal.

If you hook up the g and i terminals on a voltmeter and it reads 12 volts, as soon as you put 12v to the s it pegs.

If you just hook up the g terminal to ground and hook up 12 volts to the s with nothing hooked to the i terminal it pegs too.

Verified all that with a spare volt meter this morning

We'll call that this morning's experiment

KENO to the rescue again

Start you tuning with getting your timing dialed in. Someone will jump in with the proper timing number. Many here on this site will go with a slightly higher number than PCM states with great results . 10 or 11 degrees comes to mind, but I could be wrong. I do not remember numbers well.

Thanks Donald. Timing is good at 10 BTDC.

Quick additional question: Where should the Orange alternator wire run?   There are two orange wires. One is the Alternator and the other runs to the breaker for the ignition switch. Both are 10 gauge wires. Maybe spliced into the alternator wire?

I would post a pic of the wiring configuration, but can't figure out how to post a pic to a "reply" post......

Dave

I get 44 mph at 4500 on mine with the original prop re pitched from 13 square to 13-12.
1983 with standard engine and gear.   My timing is at 10 or slightly higher for initial number, have not checked the advance numbers yet.
I like the exterior of yours, nice job. Lets see the rest.

Joe
The quote is for you to read    He answered the question already

[QUOTE=Webster] Yes, the alternator is a marine alt. It's a Sierra International gauge called Sahara.
/QUOTE]

It probably looks a lot like this



He wired the gauge wrong and that's why it pegs.

Dave your wiring diagram is for an ammeter not a voltmeter.

You can most likely leave the Orange wire unhooked and tape/cap the end of it.

It depends how your rewiring job was done..

Pete, so the couplings matched up perfectly. The ridge on the outside of one, matched with the inside of the other coupler along with the bolts. However, I was watching this youtube video of this guy using a feeler gauge to measure the gap between the couplers, or at least I thought. So it's no problem having a .005 or so gap between the couplers on one side? Top, left and bottom......no gap in-between. Right side had about .005 gap between couplers and couplers themselves matched up perfectly. I should be good there right?

KENO, so the volt gauge only measures the amount of volts in the battery, but doesn't measure the voltage coming out of the alternator? OR if it does measure the volts being generated by the alternator, how is it measuring the volts if the orange alternator wire is hooked to the battery terminal of the ignition switch or taped off? I thought of hooking the orange wire up to the "i" terminal along with the purple wire on the volt gauge. That would be a mistake then? I still have the red wire going to the bat terminal of the ignition switch,

This is very helpful, thank you both!!

The parallel of both sides and top and bottom, I get it now. Thanks. I now should have the Volt gauge problem solved too. Thanks.

The Youtube video looked to be a few years back. An older man with longer blond hair was outside sitting in a trailered Nautique, using a dowel rod and other wooden parts to demonstrate aligning the prop with the transmission. Looked like some kind of summer get together with a fairly large family like crowd...... It was very informative.

Dave

Since you still have the red wire on the ignition switch batt terminal your solution would be to hook the orange wire to that. This just completes the circuit around the ammeter that isn't there anymore.

Then hook up the voltmeter as mentioned previously.

That would work and putting a fuse in that orange line the same size as the one in the red line would be a good idea

Or........just tape the end of the orange wire and everything should work just as it does now. since the way you had it wired the orange really didn't supply anything or do anything other than mess up the voltmeter indication.

The more I think about it, I'd say tape it first and see how things are just in case you have any other wiring "oddities" under there with the rewiring job.