1966 Johnson 20hp Low Idle

[shadowfax72]

Hello everyone!
Im just starting to get into outboard motor repair and have found this site a great resource.

I have 20hp 1966 johnson outboard that is having issues idleing down low. I have rebuilt the carburetor, which helped, but did not solve the problem. At low speeds it coughs and jerks then dies. I have tried adjusting the low speed needle but it doesnt seem to make any difference. What do you guys think i should do next?

Thanks again for taking the time to read and help out a newbie.