’83 "2001" New Problems

We went out to board today. Everything was kosher right at the start. But, midway through my set, my bud said that it was pulling real sluggish. When he hit it..it took a good 30sec before it would get up to speed. When I changed to be the driver I experienced the same thing. It felt like it was running on only 6-7 cylinders. Strange thing, is that in neutral, it would rev up good. Except, at the lower end, it seem to stumble, and at idle, it was running real ruff, unless you gave it alot of gas.

Also, there was a bad whining coming from the engine. I traced it to the impeller making alot of noise. At least it was still cooling, but real noisy.

List of things to do:

1) Change out impeller, maybe belts too.

2) Change out sparkplugs too, maybe wires, but will start with plugs first.

3) Order holley rebuild kit for the carburator and tear the thing apart a rebuild it. Never torn a vehical/marine carb apart, so it should be a good lesson.

Any other ideas or insights. The new starter is still chugging along great.

Cheers,
Brandon

get rid of the points as fast as you can!!!! try www.vintageperformance.com thats how my boat used to run when i got it. i got the high performance coil and the electronic ignition for around 100.00.

The distributor is probably a weighted system. Meaning if you open it, you will see weights on springs. The springs have gone bad and the boat can't keep the timing correct.     I had the same problem when I had my 84.. get rid of all that crap!

Sorry for the so called "bad advice"   I had a spring break in the mechanical advance go out which then after a certain RPM, the timing was off and the engine would miss. At lower RPM's you could not tell. so try again.. yes, springs go bad.

I would have to say timing. But I'm no expert right 79nautique? I am only speaking from expierence that I had on mine. If pop open the distributor, under all the guts are the weights. There are two weights. They bothy have springs on them. If one spring is worn, or my case, it was broken... I want to say that the mechanical advance was off a datsaun or something like that... (local auto store found the p/n # in an old book)

But again.. if there is anyway to get out of mechanical advance.. I would...

reverse 4 and 1 and you will have your list

I have been doing a little troubleshooting and have come across something strange.

If I test the voltage going into the ballast resistor, it is only 10.4VDC. Is this normal. Also it seems to be hooked up to the same point as the electronic choke, it sees the same voltage and has continuity. The voltage from the battery is 12+VDC. I will check the wiring diagrams to see where it is getting stepped down if it is supposed to, but I thought that the ballast resistor was doing all the reduction needed. Consequently, the voltage going into the coil is only about 5-6VDC, not the 8-9 that it's supposed to be.

Another strange thing is that every 30-45seconds I hear a sound coming from the dash, kinda mechanical sounding from one of the guages. Also, my guages seem to do strange things, like the tach shoots up when I turn the key "on" (doesn't do it always, and seems to stop acting that way after a little while). The fuel guage seems to fluctuate too while the key is on...more than just the level changing from the gas sloshing around in the tank.

Any ideas? Thanks for all the help.

The choke pulls serious current and can pull down the whole dash unless things are just right. The ignition wire is a marginally adequate guage wire for the total current.

Probe for the voltage drop, and likely the guilty component will be uncharacteristically warm, too. Ignition switch is suspect,as well as the QD in the harness. Check all the grounds for good contact.

I personally added a small relay to power the choke and alternator, so the ignition and dash are not overloaded, else more significant rewiring was in order.

AFter looking at the wiring diagram on one of the manuals, it looks like everything is being powered through the ignition switch. I will start there as find out what is suspect.

Would this low voltage be causing the rough idle issues, if the coil wasn't getting a high enough voltage to produce adequate spark at low rpms?

After looking at the ballast resistor, I determined that if I unhooked the resistor, the voltage would jump up to 12+VDC, but with it connected it would drop back down. At first I thought that the resistor could be bad. But after thinking and talking to my pops (ol' motor head and electrical engineer), he thought that the resistor was doing what it is supposed to be doing and that the drop could be just from the load of the coil being energized.

He suggested like you that I check for voltage drops from the ignition switch.

Also he said, and I confirmed with the service manual, that there is supposed to be an overide wire coming from the solenoid to the output of the resistor to temporarly provide 12V to the coil under starting situations to get a hotter spark to get it started. On my motor that aux wire is not present.

I am gonna check the ignition switch right now. I did notice a couple of spade connectors loose on the fuses that could be it.

I pulled the plugs to check the condition. They all look pretty good color wise except the #3 cylinder (viewed from the rear of the engine).

I also took the cap off the disty to check out the points and rotor. They look to be pretty new. You can see some corrosion on the faces of the points. Is the way they work is that the tip/end of the rotor brushes the corroded face of the points? Correct?

I will probably hook up the fakealake to it today and see what she runs like. It will probably idle fine and make it all that much more difficult to diagnose.

Anyone know what the Holley part number is for the full rebuild kit. I think it is 37-1539, but not sure since I can't seem to find the exact model number on the carb. I see some numbers on the air horn, but none of them are the correct numbers.

Thanks for all the help guys. I promise the bugging of yall will soon stop.

Yep. It was definitely time for a tune up. Your number 1 and number 3 plugs look pretty fouled. Your number 2 and number 6 look a little too white - almost looks like you are running too lean on some cylinders and too rich on others. So, the carb rebuild sounds like a good idea.    

Be SURE to do a compression test soon. That COULD be oil fouling your plugs.

It's very possible that the plugs fouled when you had a weak spark caused by low voltage to your coil. If the voltage came back up after you disturbed the QD, and other connections, then you definitely need to clean and lubricate those connecitons.

Your distributor cap "contacts" have a big chunk of build-up on them that restricts electrical flow (needs to be replaced). The dust inside the cap is probably a good conductor and can cause the electricity to "jump around" inside the cap and ground out on the distributor body instead of going through the wires. Of course you always replace your rotor when you replace your cap.

When you get your carb kit, check to see which power valve it came with. Many of the kits come with a 2.5 valve. You should use a 6.5 for a standard 351 in a 2001. If you call Holley's tech line (find it on their web site) they should be able to give you the correct kit number. You will want to be looking at the carb when you call them. The numbers on the air horn are not the "model" or the "series" they are the "carburetor part number" or "list number".

Good tips..

bust don't worry about the white insulators, they're supposed to be white. At optimal combustion temperatured they self-clean.

If you see gray, thats bad.

To read the plugs you need a scope or cut the threads off and measure the thichness of black ring, but get it running better first.

The carb you describe is a 4160, and there are a hundred flavors, so yes, match the LIST number of the air horn for best match.

Even your dist lobes look corroded, and a few thousanths of corrosion could be signaling a few cyllinders to fire late or early. The oddly mispalced corrosion on the cap terminals suggest this also.

I did a compression check today:

1) 150
2) 140
3) 149
4) 135
5) 150
6) 145
7) 148
8) 149

Those look to be pretty good except for the lower compression on #4, but not by much. I got the new coil, plugs, and plug wires on today. Just waiting on the disty renew kit, and impeller to come in and then I will see if anything improves before I attack the carb.

Hopefully there is a good diagram on the cylinder numbers versus where they plug in on top of the distributor. I see that the cap indexes on top of the distributor, but there are no numbers to correspond to cylinders. I guess that at TDC the rotor points backward and I can work from there according to the firing order.

Cheers