Fuel overflow on one carb
in 912 / 914 Technical Questions
6 years ago
I changed (drained, flushed with demineralized water, blew as much flush water out with my lungs, and refilled with new premixed Dexcool) the coolant over the weekend on my 11 year old (only 200 hour) 912ULS. I also changed the coolant hoses.
Anyway after a ground run-up to makes sure all was well with temperatures and no coolant leaks I noticed one of my carbs was leaking fuel through the bottom of the carb into the overflow pan and out through the overflow tube connected to the overflow pan.
** There was a steady drip / dribble from the bottom of the carb into the overflow pan
** Didn't take time to see if dribble was coming from the clear plastic carb vent tube, although not sure where else it could be coming from, especially as clear plastic tube is held against carb body by the float bowl retainer clip
Then engine isn't running rough and had its carbs balanced by a Rotax mechanic back in May. Not sure when the leak started, but it wouldn't have been there in May otherwise my Rotax mechanic would have found it.
Any ideas to what is causing the problem? My internet searches suggest anything from stuck float (someone said give it a tap with screwdriver handle), to dirt in carb to leaking floats.
I was planning on removing both Carbs this winter and overhauling, and really don't want to remove carbs (even 1) during my short flying season in Toronto - of course, safety first so I might just have to! Even though I have the equipment to balance the carbs, my Rotax mechanic friend charges me a minimal amount and is used to standing by a spinning prop - unfortunately (for me) he is on a 4 week vacation in Europe!
What can be done / evaluated without removing the carb, requiring disconnect of throttle controls and therefore rebalancing?
Looks Like I can remove the Carb from the intake manifold by loosening a single screw and pulling out from a rubber flange. Removing the drip tray looks like more work as it has two bolts attached to the same intake manifold the rubber flange is attached to. I am guessing I could remove the carb and carfeully drop the float bowl without disconnecting the throttle and choke cables?
Roger
Anyway after a ground run-up to makes sure all was well with temperatures and no coolant leaks I noticed one of my carbs was leaking fuel through the bottom of the carb into the overflow pan and out through the overflow tube connected to the overflow pan.
** There was a steady drip / dribble from the bottom of the carb into the overflow pan
** Didn't take time to see if dribble was coming from the clear plastic carb vent tube, although not sure where else it could be coming from, especially as clear plastic tube is held against carb body by the float bowl retainer clip
Then engine isn't running rough and had its carbs balanced by a Rotax mechanic back in May. Not sure when the leak started, but it wouldn't have been there in May otherwise my Rotax mechanic would have found it.
Any ideas to what is causing the problem? My internet searches suggest anything from stuck float (someone said give it a tap with screwdriver handle), to dirt in carb to leaking floats.
I was planning on removing both Carbs this winter and overhauling, and really don't want to remove carbs (even 1) during my short flying season in Toronto - of course, safety first so I might just have to! Even though I have the equipment to balance the carbs, my Rotax mechanic friend charges me a minimal amount and is used to standing by a spinning prop - unfortunately (for me) he is on a 4 week vacation in Europe!
What can be done / evaluated without removing the carb, requiring disconnect of throttle controls and therefore rebalancing?
Looks Like I can remove the Carb from the intake manifold by loosening a single screw and pulling out from a rubber flange. Removing the drip tray looks like more work as it has two bolts attached to the same intake manifold the rubber flange is attached to. I am guessing I could remove the carb and carfeully drop the float bowl without disconnecting the throttle and choke cables?
Roger
