Hi I’m trying to get my brothers boat going has a 70 hp tohatsu that run perfect before being parked up for 3 years I drained all the stale fuel, new spark plugs, used a different fuel sorce to eliminate air leaks drained carbi bowls hard to start but idles fine when warm runs rough when given a bit of throttle but sometimes will come good and run fine but soon goes back to rough and back firing so I’m thinking timing could be out, I’ve attached some videos