912 uls bing 64 issue

I've read your comments and recommendations for several years and respect what you say Roger.  I do know how to sync the carbs using the carbmate.  I target idle at 1800 rpm and the engine runs very smooth and the carbmate stays in the center green light sent at .5 sensitivity idle to 4000rpm.  Plan on checking everything out today on the right hand carb and see what I find.  This will include the idle jet.  Thank you for your help.

Thanks Roger  you are an amazing source of information   Idle jets and correct assembly  the little dots on the choke assembly and the left and right choke in the correct place. One nightmare I had was a tiny slither of runner from cutting the hoses would randomly get under the needle of the needle and seat. I had to pick it out as it never blew out that carb was checked and rebuilt by 3 rotax maintance facilities  random stuff happens 

Have a great day 

Sorry it's taken me so long to follow up on my issue.  After speaking with Roger, Dean at Lockwood, and Brian at Leaf I discovered the primary cause of the problem was WINTER BLEND FUEL.  The issues occurred on the first 80 plus degree days we had.  To complicate the right carb issue, it's fuel supply line is located very near the oil tank.  We all know how hot it gets under the cowl especially on the right side.  The solution to problem was to use 100LL fuel.  I also placed a heat resistant sleeve over the fuel line.  I performed another syncing of the carbs and engine runs like it should.  Have made two test flights in 90 plus degree heat without issue.  I have plane back.  Thanks to all and if using auto gas, I used Shell Nitro, watch out for winter blend as you transition from winter to spring.

Were your fuel hoses in fire sleeve?

Yes, but not the steel flair fitting, 90 degree, going to the carb.  It's right over the edge of oil tank and the exhaust pipe below probably contributes to heating up the fuel passing through that fitting as well.   I think the exhaust pipes under both carbs should be wrapped to minimize heat transfer.  The drip pans/shields can only do so much, but I know Rotax doesn't like wrapping the exhaust pipes.  Thanks again for your help Roger.