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New Rotax Service Bulletin about Carb Floats!

Jetguy

Jetguy

Well Known Member
Rotax has just released a new SB about Carb floats. This has been a hot item recently on the form and I was wondering when Rotax would start thinking about designing a replacement for the Current issued float and here it is!:p Brings back memories of the old fuel pumps.:(

http://legacy.rotaxowner.com/si_tb_info/serviceb/sb-912-065ul.pdf

As soon as they come up with the new float they should just send out replacement floats to all registered Rotax owners.(hey wishful thinking I know):rolleyes: The Engine serial number starts at 6 780 228 but really I had one of the first floats go bad from a 2009 dated engine so every body should be aware of this problem back to RV12 Sreial number 2.;)
 
Well, at least for inspection..

2.2) Company support information
- The parts for the inspection of float buoyancy and for the replacement of any defective
float are provided free of charge.
- Replace parts must be returned F.O.B to ROTAX? Authorized Distributors or their
Service Center.
- Shipping costs, downtime costs, loss of income, telephone costs etc. or costs of con-
version to other engine versions or additional work, as for instance simultaneous
engine overhauls are not covered in this scope and will not be borne or reimbursed by
ROTAX?.


Don't know the piddly details--it has to be inspected every 25 hours, so will they provide replacement gaskets every 25 hours of operation...
It sounds like a new set of bad parts, and maybe a new set of good parts (when developed) might be included(???).
 
Any float can go bad and has over the years. It only takes a pin hole to allow fuel into the pours of the foam core and saturate a float then it sinks. I have had two bad floats over the last 4 moths with only about 60 hrs. of time on the plane. One was on an RV12. If a float sinks there are symptoms as described in the bulletin. You can have a fuel smell both on the ground and in the air as fuel level can not be maintained inside the carb bowl. As the carb floods it then goes out the vent tube which is another symptom. Rough running can be a symptom. One easy way to check is to just pop the bowl with aircraft that has had fuel in them for a while and look at the pins on the floats to see if they are equal to the fuel level. If one is under the fuel level and the floats aren't equal then the one with the pin under the fuel is your problem.
You can weigh them, but need a sensitive scale that reads in tenths of a gram. I have a leaking carb coming this Friday. It will be interesting to see if it is the float and the hours on the plane.
If you aren't having any symptoms then I wouldn't loose any sleep over this until you get them checked.
 
Engine model applicability?

According to the SB, the following engine types are covered:

912 A
912 F
912 S
914 F

It also affects floats part# 861184 "which have been installed as spare part or doing engine repair/general overhaul since July 1, 2012." The floats were also delivered with the engines above.

I have a 912 ULS. Does that matter?
 
Dgamble said:
I have a 912 ULS. Does that matter?
Click to expand...

The service bulletin states in part in Section 1.1 Applicability: "912 ULS from SN 6 780 228".

So the answer is it depends upon the serial number of your engine.

Dgamble said:
"or every 60 days - whichever comes first."

That's crazy!
Click to expand...

I totally agree. I'm beginning to see why folks are working so hard on alternative engines. This thing is going to be apart more than it's together at this rate.
 
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If you read all the other forums about other engines they all have an issue from time to time. No ne is immune. One reason is because many parts are outsourced from other MFG's Take Rotax they make a lot of components, but the carbs are Mfg'ed by Bing. Rotax has no control over them. Gears in the gearbox are out sourced. Hoses are out sourced, ect...
All engine companies do this and have no control when another company makes a mistake. Every aircraft engine goes through this and some are far worse than Rotax is.
Plus I prefer Rotax to step up to the plate up front before everyone has to file complaints and get the NTSB involved like the auto industry. At least Rotax takes a proactive approach and and a reactive one because of tons of failures. At least they are pre-warning everyone and trying to make things like a bad batch of floats from Bing right.

Look at the auto industry bulletins and total recalls.
 
f1rocket said:
The service bulletin states in part in Section 1.1 Applicability: "912 ULS from SN 6 780 228".

So the answer is it depends upon the serial number of your engine.
Click to expand...
Well, there ya go: 6,778.547. Dodged another one. Phew! At least for now, anyway - still need to check the carb numbers.
 
roger lee said:
..All engine companies do this and have no control when another company makes a mistake.
Click to expand...
My industry experience is that the end user company has quality control checks to prevent or minimize the chances that they get bad products from their suppliers. It is a bit of twisting of words to say that a company has no control when a supplier company makes a mistake. One could say that the end user QC should have caught it and the product should have been rejected and never got put in the engine.

In addition, when the manufacturer accepts a part the ultimate customer expects the manufacturer to have assembled a functional product. If a Peterbilt truck has a rear end go out, most would go to Peterbilt, not Eaton or Rockwell.
Therefore, bad carb floats are Rotax's problem, not Bing's, as far as I'm concerned. Now, I will admit that if I learn to distrust Bing carbs that may be a reason I don't buy a Rotax engine, just as I might not buy another lawn mower with a Kohler or Kawasaki or Honda engine if my experience was that engine was unacceptable to me.
It does nothing in defense of Rotax to say that car manufacturers or others have bad parts or recalls. Saying everyone is bad is no justification to say I am not good. I find it unsatisfactory to coast to the side of the road when my Rotax airplane engine part fails.
 
Minimize and quality control is the key word and no one is 100%, but I apprieciate when any company is proactive and doesn't force the public into a showdown. Look at all products made in the world. No one is immune from having a glitch or no of us in our lifetime would have had to get a repair, warranty or take a product back from a total failure.
 
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FlyRotax.com has a List of Documents including service bulletins. Enter engine type 912 ULS and your serial number and click "Search Database". On the new screen, notice the small vertical scroll bar on the right side. The list has not been updated to include the latest service bulletin about carb floats. There is also a button to click to download an Excel file (although the PDF links in the Excel file did not work for me).
Joe Gores
 
Mich48041 said:
FlyRotax.com has a List of Documents including service bulletins. Enter engine type 912 ULS and your serial number and click "Search Database". On the new screen, notice the small vertical scroll bar on the right side. The list has not been updated to include the latest service bulletin about carb floats. There is also a button to click to download an Excel file (although the PDF links in the Excel file did not work for me).
Joe Gores
Click to expand...

Indeed this is a great service by Rotax, I wish car manufacturers were that well organized. I had to leave my Ford Edge at the dealership for a recall which after inspection was deemed unnecessary. The dealer lost no time offering to change the air filter and cleaning the fuel lines which shows how desperate they are to get customers for service (some call this practice to make lemonade with lemons)... I hope Rotax never gets there!
 
My German cousin is an IRMT who repairs ROTAX engines. When I asked for the background this is what he said:

The reason was that German ULA authorities received a report of engine failure due to carb malfunktion. Investigation showed the unequal float hight in the float chamber.....this forced Rotax to react.....
 
I personally haven't heard of a plane going down or quoting from a sunk float. It usually just floods the carb and causes it to run rough. The carbs become badly unbalanced.
That said just about the time you think you have seen or heard of everything some thing new pops up.


Has anyone else ever heard of a sunk float causing an engine shut down with the throttle advanced in cruise rpm?
I would be curious to see how many.
 
It's not as though Lycoming or TCM have ever issued any SBs or had ADs issued against their products and components, then - apart from crankshafts, carburettors, magnetos, cylinders, fuel pumps, oil pumps..... ;)
 
roger lee said:
No one is immune from having a glitch or no of us in our lifetime would have had to get a repair, warranty or take a product back from a total failure.
Click to expand...

My complaint is not that there was a problem found, or that Rotax took the time to address it. I'm very appreciative of their proactive response. My issue is with their CYA approach in the SB. Come on, really? I'm supposed to repetitively check the floats every 25-60 hours? I put about 25 hours on my -12 every 6-8 weeks. I'm not pulling the cowlings that often.

Here's my suggestion. If they know there were some bad parts, issue new floats to the engine serial numbers affected, have them all replaced, and add an inspection step in the Line Maintenance manual every 100 hours. Don't shift all the burden to me to do a stupid repetitive inspection just so they can say they warned me. Just my opinion.
 
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