For the JLPT N2, the test time limits are:
- Language Knowledge - Vocab / Grammar, and Reading: 105 minutes, 120 points
- Listening: 50 minutes, 60 points
I just took the N2, and here are some tips:
1) Bring a watch, an analog one is preferable, since alarms /sounds are prohibited.
2) The number one problem is running out of time for the Reading section. Therefore, I suggest keeping the vocab / grammar portion under 45 minutes, preferably under 40 minutes.
3) You have to FLY thru the Kanji and vocabs. If you don't know the meaning, you will never know it, so if unsure, don't leave any items blank, just guess and move on to the next. There will be no more time to go back and review your answers.
4) For the reading, keep it within 60-65 minutes.
5) For the reading, I suggest starting with the last 2 reading passages first. That's a total of 4 questions I believe. Why? Because I think those have higher points given (based on the scoring sample in the Moshi to Taisaku reviewer which is an excellent reviewer you can buy here or here in Japan), and these last questions are relatively easy, especially the information searching part.
Then, you can go back to the start / answer it from back to front which have lower points.
4) For the reading too, look at the questions first before reading the passages. That way, you can skim for the information, keep in mind. However, I still recommend reading the whole passage before answering any questions because sometimes, you will see some statements at the beginning of the passage refuted / reversed by the author by the end.
5) For the listening, there is no time to go back, once the CD stops, the test stops. Therefore, if you did not get the previous question, just guess and move on - be prepared to listen to the next question immediately. It can be distracting and cause a cascading effect of not understanding anything if you're still thinking about the previous question while listening to the current question.
Anyway, the minimum score to pass is 19/60, and the listening is fairly easy, especially the middle part where there are only 3 choices, giving you a 33% chance of guessing correctly.