You have PMd me with more questions. I don't troubleshoot via PM because only you get the benefit from that - the whole idea behind the forum is that everyone gains from every question/answer session. Repeat your questions here and they will get answered.
Valve clearance may or may not be your problem, but it is easy to check and is one possible cause - although the typical 660 clearance problem leads to a cold no-start, not quite your issue.
You claim to have fuel and spark. The only thing missing then is compression (or incorrect cam timing causing compression loss). If you prefer to not check your valves then check compression instead.
The other common failure with 660s is dirty carbs, especially pilot jets and the passages from pilot jet through fuel screw to the carb throat... meticulous carb cleaning is a pain but often necessary.
But keep in mind - if you ARE getting continuous, good spark and you ARE getting proper fuel then it SHOULD run... not necessarily well, but at least try to run and stay running. You've gone from riding to dying when letting off throttle to to not even starting... that makes me very carb suspicious.
Also read the sticky - MOST COMMON 660 PROBLEMS EXPLAINED and see if any of these match up.
What was the symptom that caused you to replace the solenoid? Also, did it EVER really run well for you or did you buy it with these issues for the most part?
'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; 05-10-2019 at 05:54 PM.