Motorcycle Repair: Problem With XJ/650/L, yamaha seca, xj 650

Question
My name is Chris and I recently I purchased a 1983 Yamaha Seca Turbo or XJ/650/L. I am very familiar with motorcycles. I have been riding my since childhood and I have never had a problem like this before. This problem is very random and seems to be electrical in origin. The symptoms are that when I am riding and sometimes when it is just idleing it randomly will cut out on me down to 2,000 rpm's. When it does this it hasn't died on me all the time, only twice on the hwy, it just seems like something electrical is mis-firing and it sounds like it is only running on one cylinder. Also when it does this I can give it more throttle than the 2,000 rpm and it seem to bog down more and "skip" in a way. The rpm guage will drop down to 0 also. I have taken the turbo, carbs, & exaust off and cleaned them. And again I am very familiar with these systems and how they work but electrical...eeehhh! So I am positive its not fuel flow and air intake. I have even gone to the lengths to take out the ignitions board and have it serviced and checked. All the electrical connections have been cleaned and the wires checked for shorts. If you have any info on how do further diagnose this problem or fix it your input would be most helpfull. Thank you for your time.                                      

                                    Chris

Answer
Hi Chris.
 Have you checked the coils against the specs in the repair manual.  You could have a bad coil or there could be a hot ground somewhere that only comes out when the system is hot.

 Due to the age of the bike, the problem could be that it needs a new wiring harness, but that is a last resort and not likely the real problem.

 No matter what, the problem is in the ignition system.

Good luck.
FALCON