---------------------------------------------------------- Yak-List Digest Archive --- Total Messages Posted Sun 07/29/18: 1 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 09:05 AM - Re: Valves inspection (\) ________________________________ Message 1 _____________________________________ Time: 09:05:11 AM PST US From: "\"" Subject: Re: Yak-List: Valves inspection Stuck here in Greene County regional airport just south of Dayton, Ohio wit h an air leak. It appears to be in the gear handle. Will be putting grand son airliner to get him home (left him today at the AF museum). Looks lik e I'll need to replace the gear valve. More trouble shooting to do. Jim "Pappy" Goolsby -----Original Message----- From: Roger Kemp Sent: Thu, Jul 19, 2018 9:24 am Subject: Re: Yak-List: Valves inspection Spot on Brother! If it ain=99t broke don=99t break it! Your A&P has to much free time and your annual inspection is going to exorbitant if you clear him hot to do this. Doc Sent from my iPad > On Jul 18, 2018, at 3:03 PM, Bitterlich, Mark G CIV NAVAIR, WD wrote: > .bitterlich@navy.mil> > > I was waiting for someone else to reply, but I guess not. > > First, the only issue I know regarding "sticking valves" is due to carbon buildup, and yes it is possible for this to get into the valve guides, but that almost always impacts the valves not seating properly and is typicall y found during a differential compression test, where air leaks through the exhaust valve into the exhaust pipes and is easy to detect just by listeni ng. Another viable method is to inspect the valves with a type of borescop e or miniature camera, which today are pretty cheap. > > Second, I have never in my life heard of a person suggesting that they re move the valve springs, which means also removing the valve keeps, which ca n easily result in the valve dropping down into the chamber stopping at the piston. Of course there is always the Indian Rope Trick of stuffing rope through a spark plug hole into the cylinder to prevent this. So my input i s that doing this at a yearly Conditional Inspection without proof of any p roblem to begin with is way way over the top. As far as "removing the valv e to clean the shaft", that means pulling the whole cylinder off. There ha s been more than one person that has dropped small parts down into the engi ne while yanking a cylinder of an M-14, so my NEXT question would be: "How much actual experience does your mechanic have on M-14 engines, and how man y cylinders (if any) has he ever pulled off? > > I could be totally mistaken, but given what you related in your posting, it sounds to me as if he is planning on gaining experience .... on your eng ine. > > It is not necessary to remove valve keepers and springs and attempt to ju dge valve movement during a Conditional Inspection. It is not called for i n any task manual from the Russians, and is not practiced by any M-14 owner that I am aware of. I'll leave this for others to chime in on. My offer would be that a compression test done while the engine is hot will quickly show any carbon build up on the valve or seat, which normally happens befo re it makes it's way into the valve guide. Regardless a borescope will sho w it in great detail and should be considered as a first step way before ta king apart valves or cylinders. > > Mark > > > -----Original Message----- > From: owner-yak-list-server@matronics.com On Behalf Of Javier Carrasco Ballesteros > Sent: Wednesday, July 18, 2018 11:20 AM > To: yak-list@matronics.com > Subject: [Non-DoD Source] Yak-List: Valves inspection > > Hello everyone, > > It is annual inspection for my Yak-55, M-14P. > > I have read a lot about the sticky valve issue, and asked the mechanics t o check on them. > > He said that he needs to remove the cylinder top covers, remove the sprin g and manually move them. > > If the stick then he will remove the valve and clean the shaft. > > Have any of you done the same procedure, agree/disagree or have any other suggestion to things to check for while he is at it? > > Thanks, > > Javier Carrasco > Yak-55 N5245H > > > > > > > > > > Sent from Mail for Wi ndows 10 > > > > > > > ------------------------------------------------------------------------------------- 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.