BAD DAY. Pro-Tec 5.8 Engine Troubles PLUS MORE.

also, check your voltage right at the protek at the engine, i suspect its quite low.

You may have resistive loading at the dash, as suggested by the dash gauge, then verify there.   It may also exist between the switch and the loads.

Both the ignition and choke pull a lot of current on that silly little purple wire. A little resistance crates a big voltage drop at the load. This wire also powers the alternator.
runs through a quick disconnect and through the keyswitch, so lots of ways to be compromised..

While operating, list voltages at battery, both sides of key switch, at choke, at alt and at ignition, that will map where the drops are. Keep the the Ground constant, do not move it around else skew the results.

If that checks out, it isolates the problem with more certainty.

If not, you can map the resistance, and remove loads to get further information.

Volt meter is screwy means a couple of things.
Could be the GND at the dash is resistive and rising above battery GND level

Could also mean that one of the loads (ignition, choke or alternator) is shunting unusualy big current to gnd due to a failure. (verses failing open). this makes the typically benign ignition switch resistance and wire/connection resistances suddenly relevent and bring the whole ignition and dash switched-power low.

To eliminate that variable, for th elast 20 years utilized a 20A constant duty aux light relay at the belhousing to energize the choke and alternator right from battery Hot , this way full voltage is better available for ignition (and the low draw for the relay). and also doesn't pull down the dash..

Hi All,

I have a 1992 Sport Nautique with the Pro-Tec carbureted 5.8. I’ve owned the boat many years and have always maintained it well. It’s never given me trouble...until today.

I should probably have known it would be “one of those days” when my Master combination lock refused to open and allow me to access my boat in the storage unit. The combination no longer allowed it to open. I had to go get bolt cutters to cut it off! Note: Bolt cutters cut through large padlocks like a knife through butter. SCARY.

Anyway, we launched the boat. Started right up. Right away, it got up to speed and I noticed the Volt meter was showing 10 volts. When I pulled the power to idle, it would show 12. Additionally, I was hearing engine noise in the stereo, so much so that I had to turn the head unit off.

Worried that I might have a bad alternator, I turned around and went toward the launch ramp. Getting near it, the boat lost power and I was able to get only about 1500 rpm. Going further would cause it to completely die. Started it again, same thing. Limped it to the ramp.

I called Vince at Discount Inboard Marine (A friend and probably one of the smartest guys I know). He had me go run and get my volt meter. When I got back, the boat wouldn’t start. I checked the voltage at at the batter and it showed 12 volts. I tightened the battery connections (positive was MAYBE slightly loose?) and we managed to get it to start, eventually. I think the neutral safety switch was the culprit there.

Voltage at the alternator was just shy of 14 volts. 13.8 or thereabouts. Same voltage at battery. Now my volt meter was showing about 13.5. But when I’d rev the engine in neutral, the volt meter would show 12 volts. Voltage at the alternator and battery still just short of 14.. (I’m thinking I may have a ground wire issue under the dash or something). Side note: Some time ago, I installed a ground buss under the dash, fed directly from engine. All under-dash ground wires went there. That solved a lot of my previous ground issues where my gauges would jump around when I added a load, ie turning my nav lights on.

After getting these good (better) readings, we decided to try it again. Went out, got up to speed, then after about 30 seconds, the power would come down and the boat would stall out. It would not want to start right away but eventually we’d get it running, but could only pull partial power.

Vince had me disconnect two sensors up front....one being water temp and the other was a sensor down by the oil filter. Both apparently feed info to Pro-Tec system. Pulling both and taking them out of the system proved to make no difference.

I towed the boat home. That in itself was a disaster. About 1 1/2 hour drive. About 15 mins from home, I noticed my left wheel was smoking. A lot. Pulled over and I had tons of smoke coming from left trailer brake. Good Lawd. I think the trailer brake emergency cable had gotten caught on the chain and had pulled. Not sure how long but it appears the left brake was engaged. And all of the grease in the bearing buddy had boiled out of it like Mount Vesuvius. I limped the thing home after letting it cool.

Could the day get any worse???

After getting it home, I pulled the fuel filter /water separator cartridge. I was hoping I’d find water and/or dirt, leading to fuel exhaustion. Instead, I have what looks like a bowl of urine with only a few specks in it.

I’m now out of ideas. I don’t think the Pro-Tec system is going into limp mode because I’d at least have a constant 2500 (approx) RPM. I cant get that at all. The boat will run then it seems to lose fuel and then it dies.

Questions:
1. Thoughts on engine issue?
2. My plan for brakes is to remove wheel and see if brake is dragging, and inspect brakes. Do I need to replace wheel bearings / bearing buddy? Not sure what to look for.
3. Thoughts on why my volt meter is so screwy??

When you decide to get bolt cutters to take your boat out for the day.....JUST GO HOME.