Indeed many of the older Fox's were easy. And even many of the difficult ones were if you followed the manual. The older carbs for example had to have the idle tuned first. If you did not know that you could spend hours dicking aound with the carb settings. But till recently they never had a carb with refined needles with positive seals. sometimesthis gaveproblems. I have a Fox .50 that runs fine. With positive tank pressure the needles do not suck air, however they do leak a bit of fuel.