Running bad... Plug Oil?Fouled? ?

[Redman]

Well, after replacing clutch cable and going for ride yesterday afternoon and again in evening . . . .

On way home the GK started running poorly. Started okay, seemed it idle okay, but any acceleration was rough, could feel regular sh sh sh shuttering and feel it some at steady speed.
Low on power, not rev well. Stalled on take off a couple times.
Made it home. THought maybe running on 2 cylinders. Muttered and cursed and walked away. (Makes me wonder how much longer I want to deal with this.)
THought maybe my clutch cable routing maybe pulled wiring off a coil or something.

(Today took RT for morning ride.)

THis afternoon I started it. Started okay, but not rev like it should. I waited about a minute or less, and felt the pipes.
1 cold, 2 hot, 3 hot, 4 warm-hot
So not related to a coil. Pondered a bit.

Took out 1 plug. It looked black and wett and like a bit of something on/in the electrode gap, but before I got too good of a look, I fumbled and dropped it (still in the socket) - scheesch- and looked like it hit the cement floor right on the electrode -dooah-
Yah, was some black gump in the gap ... had to regap it (.025- .030)... cleaned it with wire brush....

Laid it on the head, yep, is sparking.

Put it back.
Went for ride. Back to normal.

Whatda yah think? This gonna be a reoccurring problem?

THe GK does use oil, mostly will puff smoke on startup if sitts more than a couple days. (long story about its rebuild a couple years ago).



(Note I can share: I learnt long time ago, when felling if something is hot, use back of fingers where skin is thinner, and just lightly tap against it. Old experienced equipment operator taught me that my first week in industry. )

[JMHJ]

Can you use a spark plug anti-fouler/extender? I'm using some of those in an old 400sbc that needs the valve stem seals and o-rings done (but I'm not much interested in doing). They seem to work pretty well.

Have one in another old (but younger) P/U too, with a terrible oil burning 4.3L. Traced it to the number 2 cylinder and put one in; cured the misfire.

[Suzukian]

Check the oil leads for 1 and 4 cylinder, as they run off the same coil, and you are having problems with those cylinders. 2 and 3 use the other coil.

[Big T]

Oil build up on a plug looks "fluffy", gas build up looks wet
see how far it goes before it goes bad again
And, carry a fresh plug and plug wrench

[zed1015]

Smoke on start up indicates worn stem seals and when they are really bad will foul plugs after being stood overnight or at low constant speeds when the engine isn't running fast or hot enough to burn it off.
Your increased oil consumption backs this up but this may also be a result of worn bores or rings too.

[Suzukian]

The bike was running fine till he replaced the clutch cable. Sounds like something got pulled out. Maybe the wire from the coil to the plug (coil side, or spark side, I'd check the spark plug tips), it could be any number of things, but if the bike was running well, and just needed a clutch cable, I doubt all these other problems would suddenly appear. Back track what you did, and check all your connections. The plugs you are describing are not getting spark, or getting intermittent spark. The fact that they are wet means they aren't firing. You could switch coils, and see if the problem fixes itself, then the problem appears on number 2 and 3 cylinder, you know you have a bad coil. Check all the connections and make sure they're tight.

[1978GS750E]

"Took out 1 plug. It looked black and wett and like a bit of something on/in the electrode gap, but before I got too good of a look, I fumbled and dropped it (still in the socket) - scheesch- and looked like it hit the cement floor right on the electrode -dooah-
Yah, was some black gump in the gap ... had to regap it (.025- .030)... cleaned it with wire brush....

Laid it on the head, yep, is sparking.

Put it back.
Went for ride. Back to normal."

Gonna be hard to find an issue if it is running well again. Might have to see if it rears its' ugly head again! Hopefully it was just a loose plug wire! If it was, You fixed it!

[93Bandit]

Hey Redman, sorry to hear about the continued issues with the GK.

Any idea how many miles on the plugs? That might give you an indication of how long it took to foul the plug if it's from oil consumption. Although if it's black and wet, that sounds like fuel fouled as others mentioned. Ron might be right, maybe it was simply a loose plug wire and you fixed it! Sometimes it really is that simple.

[Big Block]

I can't help but think the spark lead pulled off slightly when you changed the cutch cable which fouled the plug. Or the connection to the coil got dislodged slightly.

[LAB3]

So you replaced the clutch cable and this appeared. Seems to me I'd wanna look at anything that got jossled out of place in the process of replacing that cable, there's plenty to work around as you feed it down the bars and into/through the frame

[uk gs nut]

I vote valve stem seals, since you say it uses oil. My GS1000 was an oil user and plug Groups always looked dark. I fitted viton stem seals using the rope trick with cylinder head in place. Oil use problem has gone and plugs are all good colour.

[Redman]

Thanks Folks !

Yah, I think the rough-running was not caused by the clutch cable change - but have learnt to always suspect whatever was just changed-disturbed even if that doesn't make sense. But that was my first suspect.
But 1 was cold and 4 was warm (but not hot like 2&3) so I knew that wasnt related to 1&4 coil not working at all like if connector pulled off coil.

THe black gump on No1 plug is probably related to the oil use and puff-on-startup (after sitting for a few days) and , yah, related to valve guides/seals.

(all what happened to that head on my engine rebuild 2 - 3 years ago is a long story).

I didnt get too good a look at the black gump in the plug gap cuz I fumbled and dropped the plug. So dont know if was a chunk of hard stuff (carbon buildup) or more soft gummy (burnt oil). But what I cleaned off from general area was wett soft.

Now we will just wait and see how long till reoccurs, or maybe sometime pull plug again to check.

[Suzukian]

When I worked on aircraft, I learned to never use a dropped spark plug. The Ceramic insulator can crack and under load ground. Also, you are not allowed to, and they cost about $200 bucks a piece. We would glass bead blast the sparking end, and with a pick, pick out all the lead. Then back into the plane. They last for many years, as long as you don't drop them. I found that problem only one time in all the years I have been riding. I dropped a plug, and the bike ran like cr@p. I changed the plug, and the problem was gone. That was before I worked on aircraft.