Hi Guest!
Hey - did you know if you click on the title of a thread it will take you to the first unread post since you last visited that thread?
but were afraid to ask: 
STOP!! Never post your email address in open forums. Bots can "harvest" your email! If you must share your email use a Private Message or use the 
smilie in place of the real @
Pretty Please - add it to our Events forum(s) and add to the calendar! >> 
Offline
I agree that the most likely culprit is a lean mixture but there are many ways for that to occur and chasing down the cause is often a matter of trial and error.
A number of years ago I experienced the same problem and after a lot of dead-ends finally found an object in the fuel tank that was intermittently getting drawn against the fuel pick up to cause fuel starvation and then when I let off the throttle it would fall away to the bottom of the tank--only to happen over and over. I finally pulled off the fuel sender, examined the tank's innards and found the cause--the almost skeletal remains of a large leaf that somehow got through the filler cap (don't even ask how that could happen, much less with a 100 where the filler is accessible only when the boot lid is open!!)
Removed leaf--solved problem.
A number of years ago I experienced the same problem and after a lot of dead-ends finally found an object in the fuel tank that was intermittently getting drawn against the fuel pick up to cause fuel starvation and then when I let off the throttle it would fall away to the bottom of the tank--only to happen over and over. I finally pulled off the fuel sender, examined the tank's innards and found the cause--the almost skeletal remains of a large leaf that somehow got through the filler cap (don't even ask how that could happen, much less with a 100 where the filler is accessible only when the boot lid is open!!)
Removed leaf--solved problem.
