Might be the settings on the lsn & hsn, reset back to standard factory setting & give it a re-tune, might be running to lean causing it to cut out, could be to rich causing it to flood & stall to. Does it cut out when idling, when at its correct running temperature or under acceleration, could be a number of things causing it. If the new engine in brand new then it will have to be run in & will be set rich from the factory for that purpose, then as you run it in you will have to tune it to get the performance from it. Read through some of the threads on this forum for more info on tuning nitro engines, there's some good info on here to help get them going well.