Weird things randomly started happening lately...

Hey guys, I throw myself at the mercy of the experts...

So I got my bike about a month and a half ago and put about 500 km on it without an issue. About 2 weeks ago, I was out for a highway ride (about 100km) and when I got home, I had a stuttering idle, some misfire and it seemed like the bike wasn't always firing on all cylinders.

I proceeded to look at the sparkplugs and 1 and 4 were looking normal, while 2 and 3 were flat black soot. I figured new plugs and see if performance improved. I was wrong, no change. I started to look at the ignition side and found that the coil for #2/3 cylinder had a significant crack on the underbody. Not taking any chances, I picked up some Dynatek DC1-1 replacement coils, new wires and cleaned off the spark plugs. Resistance in the boots was within spec and plug gap checked out as welll.

Now the bike seems to be showing some different symptoms. When applying throttle, response is poor and instead of going faster on my bike, it struggles and just makes a lot of noise with very little acceleration. Brace yourself - it has pods on it and was tuned by the previous owner. Assuming that since it was running well before it was properly rejetted and tuned, I decided to see if there was something funky going on with the carbs. I popped off one of the pods and blipped the throttle only to see that the slides were shuddering (jumping) as soon as the throttle was applied. I don't know if this is normal, but it sounds as though the noise that the bike is making is coming from the carbs... like a "BWWAAAAAAAAAAAA" when you give it a twist.

After a quick rip around the block, maybe about 20 min of total run time, plugs on 1 and 4 still look relatively new and 2 and 3 are black with soot...

I'm lost and need help...

 

The simple answer is 2&3 getting to much gas, carbs need to be synced and set up. Check valve clearances. NEVER trust what a PO tells you, he has to sell a the bike and will tell you what ever to do so. More experienced people on here can give you a more through list of things that need to be done. Such as remove carbs, clean carbs, bench sync carbs, wet set floats. vac sync carbs. tweak carbs. Just to start all are EASY to do. Just takes TIME and PATIENCE.

 

Thanks... That's kinda where I was headed now anyways. I've pretty much replaced most of the ignition system now so I think I can rule out that as a problem. In the back of my mind I guess I figured that if I didn't touch anything on the carbs, how could it be a carb problem?

It just trips me up a little because the bike was running relatively well up until that little trip and all of a sudden this starts, then I find a dead coil and...and...and...and... I'm half expecting it to spontaneously combust!

 

You have a motorcycle that is nearly 30 years old.

For it to be as old as that and not have a gazillion miles on it, it had to have SAT for a considerable period of time.

If you simply put it in service and expect it to behave as though it were still relatively new, it won't.

Until you go through it from one end to the other and reverse the effects of the sitting (and neglected maintenance) you can expect to have "weird things randomly start happening."

In fact, they're not weird at all. They're the symptoms of the things you haven't remediated yet. Anything you overlook will eventually turn up as a "problem."

Want to avoid all that? Read this: http://xjbikes.com/Forums/viewtopic/t=24010.html