I bought an 2002 carb. four stroke 100 HP Yammie and it runs great. Friend found a carb four stroke 70 that really runs rough. Been sitting over a year without starting it. A lot of variables, but under most conditions, would a carb cleaning kit get him running decent? I'm guessing the old gas has gummed everything up and maybe even the cylinders are nasty. Any body got thoughts, except to STAY AWAY from it. lol