912ULS carb overflowing

hi Charlie

OK, that said it would be good to find out the date of manufacture of the engine.  The "dealer" may have had this sitting for a period of time.  Rotax can look at  your serial number and then the dealer can know the date of actual manufacture from Rotax.  This will clear up if this was an issue from the test fuel or from sitting for months in the supply chain before you got your engine.  The factory orange lines have no metal in them so it makes no sense that they could be a source of metal particles.  The current factory lines also are not supplied with any underlying rubber they have a different material.  The TSO (certified) lines as  you describe are also tested by the hose manufacturer for pressure and flushed before they are supplied to Rotax for fitting to the engine.  

Cheers

I do lots of FD CT's. Here is most likely where your overflow issues are coming from. First weigh the floats when you pop the bowl off to eliminate them as an issue. Leave no stone unturned. Next remove the carbs and measure the distance from the edge of the carb bowl rim up to the flat area on the brass float armature. The carb must be held upside down. You can use a millimeter ruler for this. The measurement is 10.5mm. Last is the rubber tipped needle valve that this brass armature moves. If the rubber tip is old enough and or dried out it isn't sealing like it should and will allow poor fuel level control. These three items are easy to check.

My bet it is one of the last two items. If you need more detailed info please feel free to call. 

Thinking outside the box here, what is the fuel pressure? There is a pressure limit where the float needle seats can’t hold back the fuel. Possible fuel pump out if spec?

Walt wrote:

Thinking outside the box here, what is the fuel pressure? There is a pressure limit where the float needle seats can’t hold back the fuel. Possible fuel pump out if spec?

hm. good question. Plane does not have a fuel pressure sensor.

Would you think it is even possible, that the mechanical fuel pump itself could be out of spec? There is no electrical fuel pump installed.

In 19 years I haven't seen or heard of a FD being over spec on fuel pressure. They all tend to run between 3.5 - 5 psi. Maybe once in a blue moon 5.5 psi. If you don't have a fuel pressure sensor then this must be an early model?

I have 2K hours in FD CT's.  It's my major aircraft annual and rubber changes.