I JUST REBUILT MY CARBS BECAUSE SKI WOULD NOT START NOT PUMPING GAS,SO I REBUILT MY CARBS NOW IT STARTS AND RUNS BUT NOT SO GOOD ,I GOT SOME BACKFIRE IN FRONT CARB,,IT RAN FINE UNTILL PUMP IN CARB WENT BAD,WHY WOULD I BE GETTING BACKFIRE ,TIMING?HOW COULD I HAVE MESSED UP THE TIMING WORKING ON CARBS,PS THE JET IS NOT IN WATER RUNNING IT IN GARAGE,I WILL APPERICIATE ANY ADVICE ,THANKS

The first thing that i would check is the rotary valve. Sound like you striped your rotary valve gear in the motor. Remove the rotary valve cover and spin the motor by hand and watch the valve. Make sure that it doesnt miss a beat. Good luck

OK THANKS,I WENT BACK OUT AND STARTED IT AND IT REVS OK BUT DONT WANT TO RUN VERY GOOD BELOW 1/2 THROTTLE OR SO GOT TO PUMP IT THEN IT REVS GOOD, COULD THE VALVE STILL BE THE PROBLEM?

well got to have more info to help. What led you to rebuild the carbs. I thought you said it was backfiring.

Well started out losing top speed slower take off than just would not start ,When trying to start no gas was moving in gas line ,so I rebuilt my carbs,now gas is moving,starts runs fair about half throttle but got to pump throttle to get it there and while doing so it back fires a little but not when 1/2 or over throttle,I had my local shop do the carb work.I just removed and replaced.Thanks