Tom Baker Posted November 28, 2018 Report Share Posted November 28, 2018 7 minutes ago, Madhatter said: Maybe your instructor should call MS and get their facts before passing on unverified information. There a lot using these floats with no issues. Rotax floats have had a number of failures which may be solved, but time will tell on both types of floats. I think it is only fair to evaluate all these floats with verifiable facts, and not someone's perceived idea of how they perform. It's not like these are unimportant components of the engine. Would you consider Rotax's testing of these floats in Rotax engines a reputable source of verifiable facts? Since the instructor works closely with the factory, I suspect he was privy to their test results. Link to comment Share on other sites More sharing options...
Madhatter Posted November 28, 2018 Report Share Posted November 28, 2018 I couldn't tell you what he knows, but I know for a fact what MS told me. Obviously one of the party's is wrong. Anyone who is very concerned can investigate this issue for themselves. I spend a lot of time investigating details having to do with some of my various aviation projects, currently, and over the past many years, it is not difficult. Why don't you call Rotax and ask them why the MS floats should not be used, ask for an official statement. I would guess they would not respond to that question. I on the other hand I am going to use the MS floats and if there is a problem I will discuss it with MS. I really do not want to continue to debate this float issue anymore, I think all that has been said by everyone pretty much covers the subject for the current known information. No offense to anyone. Link to comment Share on other sites More sharing options...
david Posted November 28, 2018 Report Share Posted November 28, 2018 i have observe tht bing floats weight after some used 7.86 gram.Tht probelly OVERFLOODING the carburator. Dry weight are 6.4 gram. Link to comment Share on other sites More sharing options...
Tom Baker Posted November 28, 2018 Report Share Posted November 28, 2018 Mad, when you get your floats please report what the weight of the pair is before installation. Link to comment Share on other sites More sharing options...
Madhatter Posted November 29, 2018 Report Share Posted November 29, 2018 Today I built a bench test setup to evaluate Rotax floats vs MS floats to finally put this issue to rest ( hopefully). I fully immersed a rotax float and a MS float for several hours in ethanol gasoline. I then placed both floats side by side on the test fixture and let stabilize for about an hour. I then adjusted the fuel level to allow a straight edge to cross the container just touching the highest float. I could then measure the distance to the lowest float with a depth micrometer. The MS float was approx 2mm lower than the Rotax float. That is unacceptable. I am sure the Rotax float will absorb a little more fuel over time but not that much. The Rotax float weighed 2.9g and the MS float weighed 3.7g. Apparently the initial info from MS which was that Rotax floats absorbed fuel and that was taken into account, was incorrect. I believe my initial contact with MS was with sales people. This time when I called, today, it was the head of engineering department, Aero Accessories, Marvel Schebler. From the conversation I don't believe he was aware of this issue and he took it seriously, I will probably hear from him later. I am sure this could be a significant financial hit but the optics for the company could be worse. These floats are new and I am sure they will resolve the issue quickly. I think that maybe why everyone is not seeing this problem with the MS floats is the float level might be on the critical edge so some see it and some don't. Issues like this are not unusual in aviation (stuff happens). Link to comment Share on other sites More sharing options...
Tom Baker Posted November 29, 2018 Report Share Posted November 29, 2018 Being too heavy was one of the issues the Rotax instructor talked about. A pair at 3.7 each is .4 over the max limit established by Rotax. Link to comment Share on other sites More sharing options...
Roger Lee Posted November 29, 2018 Report Share Posted November 29, 2018 Gasoline like water has a specific gravity. It is lighter than water. With heavier floats that also means these floats will sit almost 2mm lower in the fuel which means you'd most likely have to adjust the float arms by 2mm to compensate for the difference in the bowel fuel level which may or may not work which means you most likely should just stay with the standard floats and not be a flying guinea pig. Link to comment Share on other sites More sharing options...
Madhatter Posted December 4, 2018 Report Share Posted December 4, 2018 Talked to MS today. They do not intend to change anything on the floats, said there is nothing wrong with them. Am disappointed in the conversation, he was very disrespectful and suggested I get a real mechanic to install them and readjust the float level. Their advertisement said these floats were a " direct replacement ". Adjusting the float arms would not be legal in SLSA. I suppose time will tell how this works out for them. Link to comment Share on other sites More sharing options...
Runtoeat Posted December 6, 2018 Report Share Posted December 6, 2018 Mad, good investigative work. I too am surprised by MS response to your thorough and careful comparison of the floats which is corroborated with data from other sources. If this were an automotive issue, perhaps one might take a chance and use the MS floats after recalibrating the float level, due to the cost savings. Not so with an aircraft. Lot's of people watch this forum for all things involving Rotax engines. MS might notice low sales rate for their floats (and perhaps for other carb parts if there are other choices). Link to comment Share on other sites More sharing options...
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