New Spark Plug Change, what happened!??!?!

So I bought a 1982 Maxim 750 for 800 bucks. It ran perfectly fine, I could start it without the choke every morning.

Some things wrong with it:

1.) I would get a "BATT" signal on my system check thing, it would come on then go off constantly.

2.) When revving high, it seems like it was misfiring.

Well, I figured the misfiring was probably because of bad spark plugs, so I changed them, all 4 of them, there was nasty black built up crud on them, but the guy at Autozone said that they werent the EXACT same, but the equivilent. So Im thinking, ok, thats fine, and I unscrew my old ones and throw in these new ones. But the caps would not fit on them, then I saw on each spark plug there was this little screw that was preventing it from attaching, so I took those little screws off and they fit just fine. The next morning, I go for a drive, and I cant get past 45 miles an hour! I have to rev it like crazy to even get moving, I barely made it to work.

Now I dont know whats going on. Do I need those little screws on? Did the guy at Autozone give me the wrong spark plugs? What sparkies do I need to use for my bike?

Any info would be greatly appreciated, thank you!

 

First off, what did the the Autozone guy sell you? Please provide brand and part number if possible. Did you make sure they were the same length? Did you check the plug gap? I believe they should be set between 28 to 32 hundredths of an inch. Secondly, whether or not you need the electrode tip depends on your plug caps, apparently yours do not need them.

 

You must have the wrong Plugs and with that ... the ones you have now probably aren't gapped right.
For starters.

Most Plugs you'll buy will have the Dual-end Connection.
Some Plug Caps have a large clip that slips over the wide end.
Most Bikes have narrow ends in the Plug Caps, so you unscrew the large tip and discard them.
(Or save them to give to your daughter for making a unique-looking pieice of jewelery.)

Find-out what the BRAND and the NUMBER of the Plugs he gave you are in the Bike, now.
You might need to blow them off and get a different set of Plugs.

Aside from the Plugs, you mentioned that the Old Plugs were pretty dark.
That's something you need to address ... especially if the Mixture is so Rich you are able to Start the Bike without Choke when it's cold.

Let's start you on a Fine-tuning Mission.
Get some new Plugs.
(I use Champion RN9YC -- Excellent-cost effective-reliable)

Gap the Plugs to: 32-Thousandths.
Run the Bike on the new Plugs for awhile and see what happens.
In a few days ... we'll pull the Plugs and "Read" them.
My guess is that you'll need to adjust your Pilot Mixture a TINY Bit.
Easily done.

Don't forget to unscrew the ends off from the Plugs and toss them.

 

Ooooh, maybe thats it, I didnt set them at all. Im kinda new to Motorcycles and changing spark plugs in general. I just looked up a video on how to do it so I think I gotta goto Autozone again and buy a spark plug setter. How sure are you about the 28 to 32 hundredths?

I am at work and cant provide the part number, but it was an Autolite, and it was black colored at the screw part.

 

NOT Hundredths!
Thousandths.
32-thousandths. 32/1000ths Thirty-two thousandths.

 

Hmmm, ok, as soon as I set my spark plugs and get this thing running correctly, I'm going to check it.

That crud on there was only on 1 or 2 of the plugs that I removed, the rest seemed fine. If there is build up on my plugs again, it means too much gas is being used on my bike?

 

lol, ok

What can happen if I set it more then that? can any damage be done to my bike?

 

Weak or no spark...shouldn't cause DAMAGE but it sure won't run right. I wouldn't use Autolite plugs, doubt they make one even close to correct for the XJ. Rick's advice is spot-on, and brings up another aspect of working on older machines: I try (whenever possible) to start with a functioning motorcycle before I tear into anything. Then only "fix" one thing at a time, so if something stops working or doesn't work, you have a pretty good idea what it was...in your case, it sounds like you REALLY need to get the correct plugs, correctly gapped, installed.

 

My bad! Thinking on thing and typing another!!

 

And check your alternator brushes amigo!!!