You may have some residual butane / propane mix in the cartridge that is not allowing you to fully fill the start cartridge. Please try pulling off the festo connector to the start cartridge to bleed off any excess gaz mix. Then refill the cartridge.You should get a good stream ( 2 seconds ) of clear fluid go into the cartridge. That should get the temp up and starts consistant. I do this for every run and get flawless starts on all my engines.