plugs in 98 wide glide keep fouling out any clue?

Question

my 98 HD wide glide keeps fouling the spark plugs I've already changed the air and oil filters. bike has 30000mi,I use only high octane fuel.I bought the bike from a dealership about 2 weeks ago. any info would be appriciated

by the way it is carbon fouling on the plugs not wet oil thanks

Answer 1

Either carb is faintly flooding,,float level set too high or minor float valve seepage.

Or it's simply calibrated wrong.

Go run dawgshitt outa it for a miunte,,,and see what plugs look like after winding it out in 2nd and 3rd.

It isnt unusual to see them set way rich at Low Speeds to try to get rid of the low speed pinging they're prone to.
But HiSpeed jetting is left correct.

Running it hard yields proper combustion,,decent burn & plug temps.

But chugging around town,,traffic,etc just load 'em up and fuel fouls plugs.


Doesnt sound like anything serious to me,,,
probably just over-rich at low speed

Good Luck with it

Answer 2

There are a couple of things to check. #1 is to use the fuel petcock when you park your bike. You must turn it to the off position. Gas will leak into the carb and drip into the cylinders causing a rich condition. #2 is do not use the enrichener if the engine is running. To warm it up use the throttle screw located under the throttles hand grip. #3 is that if these first two do not stop the fouling you should have the carbs looked at by the shop who does your work for you. Everybody like to mess with the carbs for some reason and it takes a skilled mechanic to do it right and make your bike run the way it was made to run.

Answer 3

Talking all around the subject. Rather than hit or miss it, troubleshoot methodically.
There are four basic causes for carbon fouling on spark plugs:

1) Rich mixture... they have more than adequately covered this...

2) oil in the cylinder but normally this leaves a slight oily residue.

3) Poor spark for various reasons bad components old plug etc, or low temperature from driving slowly or idleing (Harleys are very sensitive to this.)

4) spark to early or over-retarded timing. in a 98 this is pretty unlikely, but could happen with bad sensor or some such.

Work on these in order.

Answer 4

could be a lot of things but you can probably fix it by going 1 or 2 numbers hotter on the plugs. make sure the electrodes are the same length as the stock ones. and listen for pinging. I once got an old iron head cheap because it was fouling plugs , still did it after rejeting it 4 times all the way from too rich to too lean finally went all the way up to L 82ycs and rode it 12 years as a parts chaser with no more trouble. its still around here some where.

Answer 5

Fouling plugs in a Harley. I used to work on them back in the 90's, and I will say this. If it is a used bike, have the carb checked, you could be running too rich, and I can't tell you how many times I had bikes come by me, where the owner fooled with it to feed it more fuel, why I have no idea, especially with all factory settings otherwise. If the carb is set to mix too rich, it will give you the same result, a dirty carb will as well, especially with the new fuel mixtures out there.

Good luck with it, but there are many reasons why a Harley could start crapping plugs out.

Answer 6

If you bought the bike two weeks ago, take it back and have them fix it. Used or not, and unless it was sold As Is, the bike was sold as a good running bike. Most of the time a dealership will work with a new customer to keep him/ her happy and coming back to THAT shop. Go and explain the situation and see what they say. Be nice.
Do NOT change spark plugs to hotter plugs. They should be 5r6 H-D plugs. Use the enrichener only to start a cold engine.

Answer 7

Have the carburetor checked. Could be too rich. (dirty or settings). How much is aftermarket? Carb? Air cleaner? Exhaust? I've heard that some carbs are a pain to set properly with some mods. I've known people to ride bikes that spit, pop, and sound like crap because that's the only way it would run with that combination.

Another thing, it shouldn't make a difference, but it might. Go to a different brand gas station and see what happens.
For what it's worth, I see some carbon on my plugs and mines injected and not running rich. Gas isn't what it used to be.

Answer 8

you need to pay attention to what color the fouling actually is. most everyone assumes if it is black it must be gas fouled, but in this day and age of fuel injection that is not a good place to start. you can have two kinds of black with fouling. if the plug looks like someone dropped it into a pan of used oil (glossy) you have oil fouling which is either rings or valve seals. if the plug looks like charcoal color (dull) it is probobly fuel fouling in either case take it to a shop and have it diagnosed properly (saves time and money)

Answer 9

I agree with mustanger. The rings are the problem. Because the HD does not use a radiator they are prone to overheating and taking the temper out of the rings causing excessive blowby and oil fouling. Now you know why it was traded in.

Answer 10

If it's oil fouling then you've probably got blowby from worn rings. If so, it either has a lot more than 30K on it or the previous owner didn't take care of it.