New Rotax 912-914 Mandatory Service Bulletin - Carb Floats!

[Paul Z]

Well I've checked my Serial Number and it is before the serial numbers affected. I have had my carbs reworked but it was before the date listed in the service bulletin July 1, 2012, I had mine reworked in June of 2011.

I usually turn off the Fuel and allow the carbs to run dry, I would imagine that would allow the floats to dry out. I think I'll continue that practice.

[Av8r3400]

The main idea of the float SB is to weigh the floats. That ridiculous method of checking them is bs.

Open and empty the float chamber and weigh the floats. They should weigh (I think) from 2-4 grams and be matched pretty closely. The ones with problems weigh 7+ grams.

Easy-peasy...

[Paul Z]

I take it you called them. They are wanting people to weight them every 25 hours? Do they have any intention of replacing them? I checked my Serial Number an it was before the ones affected. I also have not had my carbs reworked after the date they specified. However, I need to replace one of my choke housing because the lever stop broke off. I wonder if I should pull the bowls and check them anyway?

[Av8r3400]

No I didn't call them. I spent the end of last week taking the Rotax 912 Service course. I'm now a certified Rotax 912 Service Technician.

(I hope to take the other two courses in the next year if possible)


I would say that if the engine is running fine there is no need to weigh or even mess around with the floats. This would be used as a step in trouble shooting a rough running motor. In the case of an airplane being used for commercial or instruction use, this SB will need to be followed at the 25 hour interval. Most likely coinciding with an oil change. Weighing the floats is a much easier method of determining if the floats have become fuel logged. I don't understand where the procedure came from in the SB and neither did the instructor. As I said its kind of BS.

I was told that there is a replacement float supplier in the works.

[Paul Z]

I have already take the Maintenance and Repair Classes, I am planning on taking the Light Sport Repairman training so I can sign off my own work!

[tommg13780]

I had my carbs rebuilt at LEAF for a cost of $1131 and they came back to me with 3 of the 4 floats bad. This happened prior to the bulletin. I spoke with Brett and he said just return the floats and he would replace. That was 3 months ago just prior to the bulletin. Now he's ignoring my phone messages. I bought 4 new floats from Lockwood, all good at $35 each. I can't believe they (LEAF) were shipping these rebuilt carbs without checking the floats.

I suggest checking the new or existing floats prior to running the engine because bad floats will make gas drizzle out of the vent and get all over the hot exhaust.

[S19Flyer]

Finally got my "new and improved" floats in. After 14 failures!!!

Now to see if I can at least get a refund for one set of them.

With so many failures I never had a need to weigh these floats. Engine ran rough 3,600rpm and below, pull the carb bowl and observe the floats. Mots of the time it was glaringly obvious. One float floating and the other one sitting on the bottom of the bowl. Or something close to that. Getting warranty for that many floats is going to be interesting.



This is on a Rans S19 but I thought it was relevant to the thread.

[KFfan]

Pretty much the same situation I am experiencing on one of the carbs on my 582

[JohnB]

That's a great photo to illustrate what happens to the floats.
I ordered my replacement floats 2 months ago and haven't seen them yet.