I have replaced the ignition system (as the factory & dealer suggested). As it was still under warranty at the time the dealer had to replace the mixer diaphram (it blew up from all the backfiring), the LP regulator and removed the intake and flushed it due the all the propane "honey". This is the only lift in the fleet I'm having this problem. If I **** the timing it quits backfiring as bad but the idle fluctuates badly. The dealer has thrown up their hands. Any ideas? Anyone else having similar problems?