becoming very frustrated with js motors. i have a race prep that will not hold a consistant tune. i had a full mod that the silicone came out of the crank. had my supplier send it back in to be re-worked and we were told they would be overnighted to us last thurs. so we would have them back in time for our first summer points race. i have yet to see my motor back. before the silicone came out, i was pleased with the full mod, but i believe the race prep will be going on ebay. after the full mod is used up,( when ever i get it back) i am going back to my old engine manufacturer. having the motor pre-broke in is great, but it is not worth the head aches i have had.