Need help with 99 T9.9

OK< need your help guys. I have a 99 T9.9 thxy. It has an electric start and automatic choke. The Motor will now not start without me opening the cowling and manually choking it by my thumb over the intake. After I do that, and hold my thumb there until it warms up...it usualy runs fine...but< sometimes< even after running it for an hour staright< it will die all of a sudden and I have to manually chooke it again. I have replaced the electric choke solenoid but the problem has not corrected. Any ideas?

[boats.net]

In most cases a through carb cleaning resolves it, make sure passages are clear.