Sounds to me like a fuel issue.How long was it sitting before you bought it? If it was more than 2-3 months,I'd suspect
gummed up carbs,especially if the last guy didn't use fuel stabilizer. If your at all mechanically inclined,take the carbs
off,being careful as to how the linkage needs to go,take the bowls off, and see what's happening in there. Also check
your fuel lines to each carb,as they can get splits in them from the rubber getting brittle with age.This would allow air
into the system and cause it to starve for fuel. Sounds like you have a good supply of parts motors,so it'll be just
a matter of troubleshooting it down. Don't feel bad. I've been troubleshooting a fuel issue with my 115 Johnson now
for the last month or more,and still haven't traced it down. Just got a brand new fuel pump from boats.net in Florida
and will be trying that this week.Hopefully that does the trick. Oh,and by the way,welcome to boating!! LOL