My 05 440 holehots almost every time but after 2 laps it comes out of corners or lands from jumps it bogs or lacks power. If I rev it in the air it comes back but will still maybe do it again during the race. Once off the track it is always strong yet. I have changed secondary spring, checked primary, changed plugs, tightened the primary clutch bolt. Any suggestions, plug caps, delrin washer?