US Warehouse - FREE FAST Shipping in USA Product Description: RB-K66 RB-K70 Carburetor for ZAMA RB-70A RB-K75 EHO SRM230 SRM-225 HC-150 HC-151 HC-160 HC-161 HC-180 HC-181 HC-200 HCR-150 HCR-151 SHC-210 SHC-211, A021000382 A021000720 For Echo GT200 GT201i HC150 HC151 PE200 PE201 PPF210 PPF211 SRM210 SRM211 Trimmer/Brushcutter for Echo Weedeater SRM210 SRM211 GT200 GT201 PE200 PE201 SRM210U SRM210SB SRM211U SRM211SB HC150 HC151 SHC210 SHC211 Trimmer Parts For ECHO OEM A021000740 A021000741 A021000742 Carburetor Repalce for ZAMA RB-K75 RBK75 When not working well: 1, oil circuit problem: fuel tank to carburetor oil supply is not smooth. Check whether the oil circuit is open, whether the tubing is choked or not, and whether there is foreign matter blocking. 2, the idle speed is too low: the new carburetor can not match the machine completely, and the old machine may need higher idle speed because of the aging or wearing of various parts. The new carburetor is based on a brand-new machine matching test, the test parameters are qualified after the factory, unable to meet the needs of each customer's different parameters. This situation needs to increase the idle speed: the valve screw at the red circle arrow (clockwise adjustment of 1-2 rings) 3, the negative pressure hole is blocked: the negative pressure hole is blocked also cause the extinguishing situation. Check whether the negative pressure hole in the red circle is blocked when it is installed. Thank You for Shopping!