Overcharging 16.5V

1996 Jonhson 115hp v4 10amp stator 35 amp regulator.

I'm on my 2nd voltage regulator on this thing. Had turned off the battery switch while it was running (yeah I know, don't do that) It of course fried the VR. Got another one and it did the same thing charging 16.5. Called CDI, they said to replace the battery. I cleaned all the connections and replaced with an Exide / Interstate XXHD 1000mca starting type battery.

Just got done splitting all the accessories over onto the Deep Cycle and putting in a Voltmeter on the starting/charging side. Start her up and the voltage slowly climbs to 16.66 volts nothing else drawing on that battery.

I'm really stuck at this point - even bypassed the a-b-both-off switch with cables direct to the battery - same results. Stainless washers lock washers and nuts used on the battery all the connections are clean and tight.

This all seems to have started when I did the bonehead move of switching off the power while running the engine. I would think if the stator was damaged it wouldn't be putting out voltage.

Could really use some help on this one.

BTW- the tach does not register while running switch on drops to zero and stays there. The tach has been replaced as the other was fried when the initial damage took place.

Re: Overcharging 16.5V

One question: Why remove the loads from the battery that is being overcharged? On my unregulated 60hp Johnson, I added running lights to add load to keep the voltage lower when it climbs over 16 during long, high RPM runs. One thing I can think of is that you need to make sure the ground on the regulator is good. The ground has to carry excess voltage back to ground at the block. I see that the regulator is grounded though the mounting bolts, it could be not grounding to the block because of excess sealer, or corrosion.

Re: Overcharging 16.5V

I have an old 55 hp, it is unregulated as well. My solution: crank the stereo when I notice the volts climbing over 16. Typically its around 14 but if I run WOT for extended periods it can climb up over 16. Havn't had to replace my battery yet (knock on wood)

Re: Overcharging 16.5V

I do have it gooped up real good with sealant. In the past the OEM VR had some corrosion near the front of the gasket surfaced, fixed it but now put extra sealant on the area rather than OMC gasket cement. These CDI VR's are powder coat or epoxy dipped so there's no bare metal. I suppose the star washers should cut in a bit. I will run a ground strap to a good engine ground and give it a shot.
Wonder if it's toasted another VR just running at Idle for a maximum of 3 minutes?

CDI actually instructed me to keep as many accessories on the other battery, Deep cylcle and not charge that one via the Stator- V/R. They said the stator (10amps) was only good for charging a starting or dual purpose lead acid flooded battery with tilt/trim and the starter. I've got the switch rigged to start off the deep cylcle if necessary.

Thanks for the help guys, I'll post the results in a couple days, but I wonder if the VR is toast now?

Maybe this will fix the Tach too.

Re: Overcharging 16.5V

What is the specification from the factory for the voltage output? I know my battery charger at home will push nearly 16 volts while charging.