The summer signing from Anderlecht started at Upton Park on Saturday as the Hammers were beaten 1-0 in their opening match of the season.
Despite putting in an energetic display against Spurs, Kouyate is confident that he can get better as the campaign progresses.
"I think I can still do better," he told West Ham TV. "I'm not yet at 100%, so I'll be doing even more work. Now that the league's begun, I've got to work hard in training to find my rhythm.
"As soon as I'm at 100% I'll really be able to give more than I was able to on Saturday. Not bad, I know, but I'm certain that I can do better still."
West Ham continue their Premier League campaign this Saturday when they travel to Crystal Palace.