Here are the specific tools required to open and maintain your nitro engines
Reference 37TT-056
Brand: T-WORKS
Piston Retainer Clip Assembly Tool - TT-056
Reference 08107050
Brand: HUDY
HUDY PROFFESIONAL ENGINE TOOL KIT FOR .12 ENGINE - 107050
Reference 03AR1312
Brand: AIGOIN RACING
Sleeve extractor for .21 engine - AR1312