At 4 months, you are probably dealing with puppy coat which is prone to matting and has a terrible texture.
I would trim at least the edges off. It could take a year or more to determine the actual quality of his coat.
To combat matting, use a good conditioner. For detangling, use something that gives the hair "slip." There are so many great choices from corn starch (use dry on dry coat) to my favorite, Pet Silk Silk Serum. Some people like Cowboy Magic or brushing sprays.
For severe tangles, I like to use the pic on the Madan rat tail comb and carefully pick apart the mat. I bought mine from Jenny (Mimimomo) at her store
toplinepet.com
I also like using a good metal comb, taking a small section of hair and starting at the bottom and working my way up.