1985 Interceptor vf700f slow loss of power

I have an 85 vf700f interceptor. it runs well, but it randomly shuts off during riding. It only happens when the bike is at normal operating tempurature. I will be riding and the RPM's will slowly start to decrease. I will down shift to get them back up and they will continue to slowly decrease. If I let off the throttle, the bike will completely shut off. So I down shift until the RPM goes so low that it shuts off. Now i repaired the wiring harness that goes from the voltage regulator to the fuel pump. It fixed it for about 1-2 months. Then it randomly came back again. The harness is still good. The oil level is perfect. Gasoline level is always good. I do not know where else to go. I gave it a new fuel filter, oil change, and fuel change. I cleaned the inside of the tank. It was really good considering it sat for about a year. It did get ran up every week, but not drove very much. After it dies, I let it sit for a little while and it will start right up. Sometimes I can go a few weeks with no problems, but then sometimes I cannot go a day without it happening. I am clueless where to start. I do not want to just start replacing random stuff and wasting a bunch of money. Where do I start? It almost sounds (when it starts to lose power) as the exhaust is clogged. I have aftermarket Kerker exhaust so I highly doubt that is the problem. Any one have any idea???

 

Check Electrical Troubles.
What About Temp. When Your Bike Begin To Decrease Power ?
Lamps.

 

I had a weird thing on my Nighthawk that would do the about the same thing. It was acting like it ran out of gas. Turned out that my gas cap was not venting so it would create a vacuum in the tank and not allow fuel to flow after about 8 miles of riding. Ofcourse I would open the tank and look in and see gas, close cap, try to start and would run fine. I found out what it was when I went to change tanks and was letting the fuel drain out the hose. When it stopped I knew I had more gas in it, so I opened the cap and it started to flow again, thats how I figured out why my bike kept dieing. Your problem maybe completely different but thought I would share.

 

Water temperature is good. I have never changed the regualtor/rectifier. brand new battery with perfectly clean and corrision free connections. How would I check the R/R? Just buy a new one?? I do not think that it is the gas cap. After it shuts off, I open it and close it and it will not start until the bike cools down for about an hour or so. If I mess around with it for a little bit, I can get it to start and move about 1/4 mile or so until it dies again.

 

+1 for this being a possibility. It could also be the tank valve (you know, the ON-OFF-RES switch). Those are cheap to replace, like $10, so it's worth a try. I've attempted to clean/repair those and it never works.