yamaha 50 hp noise from bottom end

[David s?rensen]

my yamaha 50 from 89 had the lean sneeze yesterday took tha carbs off and cleaned them and took the oil blend system off it runs great now but i got this strange noise from the bottom end now sounds like a blown bearing but only at idle i dident took the oilpump off the engine i only blocked the hoses do i realy have too put in some new main bearings...

regards

David S?rensen, Denmark