Do you have a inline fuel filter if so try changing it. About three years ago I had a problem like you describe when the weather was hot. I changed the fuel filter and the problem went away for a few hundred miles changed the filter again and it went away again. to shorten this story after afew more filter changes it stopped happening. I cut a couple of the filters apart to find them full of what looked like a black powder. What was strange was it only happened in hot weather. I had the problem start after I had filled up with gas in Lenoir N.Carolina and noticed the station went out of business the next day. I came to the conculsion that the cloged filter made just enough resistance to cause problems when the high temp was aready causing everything to have to work harder. I know this sounds weird but I now carrry a spare filter in both rods, and I buy the plastic housings so I can check for deposits.
