Plugs Keep Fouling(smell like gas)

[risccas]

OK, so here's my bike info:
1983 GS-1100gl all stock
21K miles

OK, so here's my situation:
The plugs keep fouling out and reek of fuel. I will change out all four plugs, it will run perfect for about two weeks. Then One day I will go to start it and it will idle and run pretty rough, back fire, and only have about half it's normal horsepower. I change out all four plugs and I'm good to go for another two weeks.

Can't figure out what is causing this. Could it be something w/ the carbs since the plugs smell like fuel, maybe the carbs need tuned...???

What say you?

[DaveDanger]

Just out of curiosity, do you have any success cleaning and re-using the plugs? Had an old bike once that oil fouled the plugs pretty quickly, I simply kept a spare set, and literally swapped them on the side of the road when I needed to, then cleaned the dirty ones at my first chance. I'm just curious to see if your plugs are being ruined in some fashion, or if they're just dirty and will work again after being cleaned. (I have access to a glass bead blaster which makes the cleaning easy, but it can be done nearly well with a spray can of brake cleaner and a wire brush). As to troubleshooting, it sounds like you maybe need to do a series of plug chops at various throttle settings. That'll give you some baseline information on your fuel mixtures and give you a starting place to determine the problem.

[scotty]

Does it always smell of fuel or only just before they foul again????

[risccas]

I only smell the fuel on the plugs after I remove them once they have fouled.

[flyingace]

You say 'fouled' - exactly what do the plugs look like (gas wet, oil wet, dry&sooty, etc.).

Are all plugs effected? If not, which?

[risccas]

They are dry and black, but reek of fuel still. They are NOT oily or wet at all.

[scotty]

you are obviously geting too much fuel but not so much that it ruins the plugs imidiately. first of a number of posibilitis isfloat levels a bit out of wack. Has anyone done carb work recently. as always run gas treatment through a few tanks of gas if you already havent. zbut if it is the same on all 4 jugs i would suresly suspect that whatever was dfone was done to all the carbs

[flyingace]

First and easiest to check is your fuel petcock. If it's stock, the vacuum may be broken allowing fuel to flow into your carbs as if on prime. Just disconnect it from the gas line and turn it on (straight down). If fuel flows when the engine isn't running, it needs to repaired or replaced. I would also check the air filter - is it badly plugged? It could even be a weak spark leading to incomplete combustion.

It seems unlikely to me that all float levels or needle/seats are going to go bad at the same time - unless recent carb work was done. That's why I asked if the plugs were all fouled or some combination.

[risccas]

What kind of "fuel treatment" should I use? And what is the reason for doing this?

[scotty]

What kind of "fuel treatment" should I use? And what is the reason for doing this?

Use cheapest one just dont use carb cleaner. the advice in the previous post should not be ignored. usuall nothing is a quick fix. Use gas treatement just in case there is any shelack or whatever built up in carbs. it is a pet maintainance of mine even though i never buy a non running machine. dont expect miracles and again i will urge you to try the petcock test.

[Hotblack]

It might be a good idea to check your fuseblock connections, if you haven't. I strongly suspect that intermittent weak spark can be caused by bad connections (not to mention plug leads and such), and can lead to these kinds of headaches. It's also a relatively easy thing to verify before you tear into your carbs.

[moto_dan]

What brand of spark plugs are you running?

[risccas]

Hi Hotblack. I'm so glad you stated that possibility. How would an intermittent weak spark cause my problems?

The reason I ask is because I do have an intermittent weak spark(I think). I have a poor connection between one of my plug wires and the rubber boot that it connects to. Shortly after I purchased the bike, the plug wire had come completely out of that rubber boot that fits over the spark plug. So I just stuffed it back into that boot. After that I noticed I could always here a sort of electrical tapping noise coming from around that plug.

I guess I should have mentioned this before but I honestly had forgotten all about it untill now.

What do you think?

[risccas]

NGK plugs, the same model# suggested by suzuki.

[Hotblack]

Hi Hotblack. I'm so glad you stated that possibility. How would an intermittent weak spark cause my problems?

The reason I ask is because I do have an intermittent weak spark(I think). I have a poor connection between one of my plug wires and the rubber boot that it connects to. Shortly after I purchased the bike, the plug wire had come completely out of that rubber boot that fits over the spark plug. So I just stuffed it back into that boot. After that I noticed I could always here a sort of electrical tapping noise coming from around that plug.

I guess I should have mentioned this before but I honestly had forgotten all about it untill now.

What do you think?

Well if you have a cylinder that loses some or all of its spark during operation it won't burn the fuel mixture well (or at all) and that can cause problems including fouling, flooding, and even washing down your cylinder walls with raw gas. This last is nasty because if it gets by the rings it will negate lubrication and you can ruin the engine. Well that's if you run a cylinder with NO spark.

Your ignition glitch sounds a little too irregular to cause the regular fouling you describe, but it's worth investigating further. If you have a regular electrical glitch, like say, a connection that heats up under certain conditions and loses conductivity, that could cause some kind of regular fouling. there could be another variable like a weak spark that will ignite fuel until conditions slide just enough so that it can't cope anymore, then things go downhill from there. Or maybe you do something regularly when you ride that overwhelms the spark and things go downhill. Once you start fouling it just gets easier to foul as the sparplug becomes more and more choked.

At any rate it can't hurt to fix that plug boot problem and make sure the elctrical end is good. As far as an actual defective ignition component, well that could certainly do it too, and they can be hella hard to diagnose. At that point maybe it would be more fruitful to shift your efforts to the fuel issues and make sure they're all straight.

My point is that I like to (doesn't mean I always DO :roll: ) work on the easiest/cheapest things that could go wrong first, and pregress to the harder/more costly items. So probably you should first make sure the carbs aren't getting flooded, as this is very important to keep your engine from being ruined, then check your ignition fuse connections, and bullet connectors, any connections for ignition components, plug leads, etc. You might have to dive into the carbs if you don't find anything wrong, and hopefully it won't get to trying to isolate an ignitor that is heating up and crapping out on you. Hmmm I wonder if burned or damaged intake valves could do this? That would be one to check later in the game as opposed to earlier. Oh and trying fuel system cleaner before diving into the carbs sounds like good advice too. I've used that Techron stuff and it's expensive but it really works.

Good luck!