---------------------------------------------------------- Yak-List Digest Archive --- Total Messages Posted Mon 03/04/19: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:01 AM - Re: Carb discussion and canopy seal (Richard Goode) 2. 07:11 AM - Re: Carb discussion and canopy seal (jay-dub) 3. 01:39 PM - Re: Carb discussion and canopy seal (Peter Scott) 4. 06:23 PM - Re: Carb discussion and canopy seal (motoadve) ________________________________ Message 1 _____________________________________ Time: 07:01:15 AM PST US From: "Richard Goode" Subject: RE: Yak-List: Carb discussion and canopy seal Certainly. The pilot was flying an aerobatic routine in France when he recounted (subsequently) that the engine missed and then recovered, but over about 10 minutes it became worse and worse and then finally the engine was hardly delivering any power at all, hence his doing an emergency forced-landing in a field, where the propeller hit the ground, hence causing the need for a shock-load inspection, which we have to do in Europe. We sent the engine to Aerometal in Hungary, and I said to them that, from my experience, the issue sounded rather like a coil problem. However they dismantled the engine; no problems at all; reassembled it and then, as is our usual practice, put it on the dynamometer to test it. However it wouldn't start, and after a bit, Aerometal realised there was a carburettor problem; dismantled it; found a "tear" in the membrane; replaced it and the engine ran perfectly. I have asked them if they can find the old membrane and give me a photograph of it. If I do get one, of course I will publish it. But, I certainly know of another three membrane failures, typically causing excessive fuel in the engine and then partial engine failure. One was in a Yak 55 which was clearly running badly and so the pilot elected to return to his home airfield and then on finals to land he was coming a bit low; opened the throttle, and nothing happened so landed just outside the airfield, fortunately with no damage! Richard RICHARD GOODE AEROBATICS Rhodds Farm, Lyonshall, Hereford, HR5 3LW, UK Tel: +44 (0)1544 340120 Fax: +44 (0)1544 340129 e-mail: richard.goode@russianaeros.com www.russianaeros.com WORLD LEADERS IN RUSSIAN SPORTING AIRCRAFT & ENGINES In partnership with Aerometal Kft, Hungary. From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of Jill Gernetzke Sent: 03 March 2019 22:55 Subject: RE: Yak-List: Carb discussion and canopy seal Richard, Could you provide us with the details of the membrane failure, symptoms of a problem prior to crash, etc. that would be beneficial to the group's knowledge and awareness. A picture of the failed membrane would be nice. Thank you! Jill Gernetzke M-14P, Inc. ________________________________ Message 2 _____________________________________ Time: 07:11:37 AM PST US Subject: Yak-List: Re: Carb discussion and canopy seal From: "jay-dub" > > Certainly. The pilot was flying an aerobatic routine in France when he recounted (subsequently) that the engine missed and then recovered, but over about 10 minutes it became worse and worse and then finally the engine was hardly delivering any power at all, hence his doing an emergency forced-landing in a field, where the propeller hit the ground, hence causing the need for a shock-load inspection, which we have to do in Europe. Substitute UK for France and the fact that I was able to deadstick it back in, thats almost a carbon copy of my incident. Hopefully will get an answer next week when my partner and I open it up. [/quote] -------- CJ and Yak-52 owner Read this topic online here: http://forums.matronics.com/viewtopic.php?p=487908#487908 ________________________________ Message 3 _____________________________________ Time: 01:39:11 PM PST US From: Peter Scott Subject: Re: Yak-List: Carb discussion and canopy seal Price for the canopy seal, please Jill? Or via separate email, I sent. Peter Scott PLEASE NOTE MY NEW EMAIL ADDRESS is peter@scottbase.id.au Please use the new address in future communications. On Mon, Mar 4, 2019 at 10:06 AM Jill Gernetzke wrote: > Richard, > > > Could you provide us with the details of the membrane failure, symptoms of > a problem prior to crash, etc. that would be beneficial to the group's > knowledge and awareness. A picture of the failed membrane would be nice. > Thank you! > > > *Jill Gernetzke* > > M-14P, Inc. > > ________________________________ Message 4 _____________________________________ Time: 06:23:48 PM PST US Subject: Yak-List: Re: Carb discussion and canopy seal From: "motoadve" jill(at)m-14p.com wrote: > I have submitted the pix, but they are not posting for some reason. If you > want to view the pix, I will post on M-14P, inc. FB page. > > Have a great weekend! > > Jill > > Group, > > I am late to the discussion, but needed to clarify that an AK-14 diaphragm > can be utilized on the Huosai or AI-14 Carburetor (K-14). There are two > additional holes in the AK-14 diaphragm. These are of no consequence as it > is sealed between the two parts of the carburetor. > > I do not have a Huosai carburetor apart, but I have attached photos of the > K-14 carburetor. The original carburetor diaphragm also has two additional > "blind holes" in a different location than the Ak-14 diaphragm, but > nonetheless, "holes to nowhere". > > If there is still debate about why the Ak-14 diaphragm will not work, I > would like to hear the reason, as I am always open to learning. > > The bigger issue, in my opinion, is people thinking that they can change out > a diaphragm and "fix" their carburetor. In all of the years that we have > been overhauling carburetors, we have only had 3 defective diaphragms.(None > resultant in a catastrophic failure.) It really is a testament to Russian > engineering. As Richard stated, the carburetors should be overhauled every > 6 years, or so. There are numerous o-rings in the carburetor that go bad > with time and heat cycles. The butterfly shaft has 3 o-rings, alone. The > actuating assembly is in a lubricating bath of turbine oil. This area of the > carburetor is very close to #6 exhaust, so it is more common for these > o-rings to be a problem than a failing diaphragm. Sometimes, people mistake > leaking fluid from the bottom of the carburetor as fuel, but if they really > look and feel it, they may find it is turbine oil. The o-rings are no > longer doing their job on the butterfly shaft. The beauty of the Russian > design is that the o-rings serve as both a seal and a bearing surface, so > wear is minimal if the carburetors are overhauled at prescribed intervals. > Any use of Mo-Gas with ethanol will destroy the rubber bits in the > carburetor, fuel pump and even fuel hoses. Stay away from it. > > Also, replying to the request this morning for Yak 52 canopy seals (leather) > - We stock them. > > > Jill Gernetzke > M-14P, Inc. Do you overhaul carburators for the Housai engines also? -------- www.Backcountry182.com Cessna 182 P CJ -6 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=487928#487928 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message yak-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Yak-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/yak-list Browse Digests http://www.matronics.com/digest/yak-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.