Fuel starvation, when this happened to me, there was a pinched fuel line to blame. Ran great at low RPMs, put on a load and it would actually stall. You might check anything that could affect fuel pressure ... Good Luck -- "Thinking is the hardest work there is. That's why so few people undertake it." - Henry Ford Bill Pugh 1957 TR3 "Casper" TS16765L Wallace, CA