RE: Moki 210 idle issues
Check the O-Ring on the low speed disk. You may have a small air leak or tear. I think Hobbypeople.net carries new ones (Mark Engine). Also what plug and fuel are you currently running, along with prop size/brand and are you using a CLine Reg.
1700rpm is still very very high for an Idle. How is the transition from low to mid & mid to high? It wouldn't hurt to pull the carb off and apart while flushing and cleaning each area well.