Here are some pic's of the Walbro WT-644 mounted to my SV-26. You must level the primer buld on the carb according to the dealer I bought it from. He said it would never run right if you remove it. He told me to just put a plug in the fuel intake for the primer buld and it would work OK. The WT-644 is the standard carb used on the Zenoah G-26 for Heli's and boats. The Zenoah G-26 with this carb spins a APC 16x8 prop at 9000 RPM. I hope to get very close to that. I'll post my results after I test run it this weekend.