I'm guess you mean GXV270, a vertical-shaft engine, is that right?
Tell me what kind of machine / equipment it is powering.
There are many different types of the GXV270 engine, but I can help get you some troubleshooting if you can share the engine's serial number with me. It's stamped into the side of the block, and should have 5 letters and 7 numbers, like "GXXXX-1234567"