Read the "Most common 660 problems" sticky in the 660 maintenance section - especially about the RPM limiters.
Clean the CARBS not just the main jets. The small passages from the pilot jets and the fuel screws clog up and cause lots of problems.
Tell us more detail about your problems - and any history you may have with the quad - how long has it sat, when did this problem start, etc., etc.
You now have two threads about the same issue - not cool... try to answer all the questions that have been asked of you in both so we can help you better.
'01 660 Raptor, Burgard +2+1 arms, YFZ Shocks, LSR anti-vibe, CTR pipe, jetted, K&N
'01 Polaris Scrambler 400, K&N
'02 Honda 400ex, Big Gun pipe, jetted, K&N, Lonestar +2 A-arms, Lonestar anti-vibe
'04 Suzuki LTZ400
'16 RZR XP4 1000 Turbo
Last edited by QuadManiac; 04-09-2019 at 08:29 PM.