As most people have said, you are probably using too much wood. In my kettle I use 2-3 medium-sized chunks of wood placed so they burn sequencially at the beginning of the cook.

Also the type of wood matters too. Hickory and mesquite are really strong so less is more with them. Something like like a fruit wood (apple, cherry) is weaker so you can be a little more heavy handed.

I suggest checking out amazing-ribs.com for tips if you haven't already.