83 gs1100gk missing under acceleration

[swedge61]

This is my first post, please bear with me. I bought the bike about 8 weeks ago. It wasn't running well so I changed the plugs, fuel filter, and cleaned the air filter.The bike ran good after tune up. I picked up some bad gas a couple weeks later. I drained the tank and it started running better after a couple of tanks of gas. We went on a trip to the Smokys and road around. The bike was running good a first then it started missing againlike it had bad gas. I changed the fuel filter and checked the plugs. The plugs are dry and black so its probably running a little rich. The carbs had been done by the previous owner. The bike starts fine and runs ok if you gradually pick up speed. The problem is when I accelerate the bike starts missing bad. The problem is worse if my wife is with me. The bike has 29,000 miles and looks good. We really enjoy riding it.I hope someone can help me. I have been reading the forum and it has helped me several times. Thanks

[Grandpa]

The GK is a wonderful bike. My 1984 GK has 118,000 miles on it, all but 25,000 are mine. You should enjoy it for many years and lots of miles.

Suggestion about your problem, from a long-time GS rider, now deceased, by the name of Ray Snowdon. Ray used to have a 79 GS850 and an 82 GS1100G. The latter has practically the same engine as our GK's. Ray noticed a slight miss on acceleration, on his 1100G. He tried this and that, got into all kinds of trouble-shooting, some of it complicated. Still the mighty 1100G missed, only slightly, but it kept bugging that perfectionist Ray.

He finally diagnosed the problem, almost by accident. It was the spark plug caps. He replaced the stock spark plug caps with NGK units, available at many dealers. Problem solved.

So, I suggest you start there. You can order these NGK caps through your dealer or on line. That's what I have on my GK. I forget the stock NGK numbers on them, but someone may drop a line on this thread and tell us.

[swedge61]

The 1 and 4 plug have ngk caps but the 2 and 3 plug caps look much older. I will replace the caps. Thanks for the advice.

[Grandpa]

Let us know whether this fixed the problem.

[swedge61]

I measured the resistance in the plug caps and found that the plugs 1 and for were 5 ohms and plugs 2 and 3 were 9 ohms. I dont know if 9 ohms is too much. I haven't been able to get to the parts place to replace the caps so I trimmed all the wires back about a quarter of an inch and reattached the caps. One of the wires looks like it has some cracks in it. The bike still misses under any load until it gets good and warmed up then it seems to run pretty good with only a miss every now and then. I haven't went on a ride with the wife to see how it does with both of us.
Could the cracked wires or weak coils cause a problem? how do you check the coils? I am a little new at the use of a multimeter. Thanks grandpa for your input.