My victa super 600 has become incredibly hard to start. Numerous trips to the fix-it shop get it going for a short time and then after one big mow, next time it's back to hard/impossible starting again. Can anyone tell me the range of things that make a mower become hard to start so that I can make sure the fix-it shop has covered all options? The mower is in otherwise good condition, had a new belt fitted last month. Or is there some special problem that happens over time with the super 600?