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Valves inspection

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javiercarrascob

Joined: 06 Sep 2009
Posts: 62
Location: Virginia

Posted: Wed Jul 18, 2018 7:19 am Post subject: 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 to check on them.

He said that he needs to remove the cylinder top covers, remove the spring 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 Windows 10

mark.bitterlich(at)navy.m
Guest

Posted: Wed Jul 18, 2018 12:04 pm Post subject: Valves inspection

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 typically found during a differential compression test, where air leaks through the exhaust valve into the exhaust pipes and is easy to detect just by listening.  Another viable method is to inspect the valves with a type of borescope or miniature camera, which today are pretty cheap.



Second, I have never in my life heard of a person suggesting that they remove the valve springs, which means also removing the valve keeps, which can 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 is that doing this at a yearly Conditional Inspection without proof of any problem to begin with is way way over the top.  As far as "removing the valve to clean the shaft", that means pulling the whole cylinder off.  There has been more than one person that has dropped small parts down into the engine 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 many 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 engine.



It is not necessary to remove valve keepers and springs and attempt to judge valve movement during a Conditional Inspection.  It is not called for in 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 before it makes it's way into the valve guide.  Regardless a borescope will show it in great detail and should be considered as a first step way before taking apart valves or cylinders.



Mark

--

wlannon(at)shaw.ca
Guest

Posted: Wed Jul 18, 2018 12:17 pm Post subject: Valves inspection

Only two things I would recommend at this time:------

  

 1. Start using MMM in the fuel and

 2. Get a new mechanic.

  

 Walt

    

  From: Javier Carrasco Ballesteros (javiercarrascob(at)yahoo.com) 

 Sent: Wednesday, July 18, 2018 8:19 AM

 To: yak-list(at)matronics.com (yak-list(at)matronics.com) 

 Subject: 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 to  check on them.  

He said that he needs to remove the cylinder top covers, remove the spring  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 Windows  10 

 



  	          		Virus-free. www.avast.com 		 	 [url=#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2] [/url]

Looigi

Joined: 20 Apr 2015
Posts: 81
Location: Christchurch, New Zealand

Posted: Wed Jul 18, 2018 12:36 pm Post subject: Re: Valves inspection

Hi Javier,



As an A&P who has my own yak-52 I echo Mark comments.  The only time you should be doing pulling bits off your airplane is for routine maintenance or when something is busted.



Pulling cylinders for an inspection is, in my opinion, not a smart idea.  A good analogy would be open heart surgery to have a look at your heart valves!  You are introducing the risk of infant mortality unnecessarily.



Do a leak down test and bung a boroscope into each cylinder and have a look around that way.  A failing valve will stand out a mile if you know what you are looking for.  There is a very good series of videos on Youtube by a guy called Mike Busch (Savy Aviator), one on valves.  While Mike has much bigger balls than I do when it comes to maintenance his principles are sound and he gives good and well thought out advice.



The moral of my story is the old saying.... If it is not broke, don't fix it!



Chris

jonboede(at)hotmail.com
Guest

Posted: Wed Jul 18, 2018 12:45 pm Post subject: Valves inspection

I second this motion. 

 

 On Jul 18, 2018, at 3:34 PM, Walter Lannon <wlannon(at)shaw.ca (wlannon(at)shaw.ca)> wrote:

 

 

  	  Quote: 	
		        Only two things I would recommend at this time:------

  

 1. Start using MMM in the fuel and

 2. Get a new mechanic.

  

 Walt

    

  From:  Javier Carrasco Ballesteros (javiercarrascob(at)yahoo.com) 

 Sent: Wednesday, July 18, 2018 8:19 AM

 To:  yak-list(at)matronics.com (yak-list(at)matronics.com) 

 Subject: 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 to check on them.  

He said that he needs to remove the cylinder top covers, remove the spring 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 Windows 10 

  

 

 

 

 

      Virus-free.  www.avast.com     [url=#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2][/url]

Robin Hou

Joined: 19 Jan 2017
Posts: 15
Location: El Monte, CA

Posted: Wed Jul 18, 2018 1:43 pm Post subject: Valves inspection

Not a M14-p owner, but my Housai will shake and growl with sticky valve. After shut off, the offending cylinder will be colder to touch compare with others. I have had good luck feeding my Housai with MMO in oil and fuel to cure sticky valve. No need to remove a cylinder for 6 years and over 300 hours.



On Wed, Jul 18, 2018 at 1:46 PM Looigi <cdoburton(at)gmail.com (cdoburton(at)gmail.com)> wrote:



 	  Quote: 	
		  --> Yak-List message posted by: "Looigi" <cdoburton(at)gmail.com (cdoburton(at)gmail.com)>

 

 Hi Javier,

 

 As an A&P who has my own yak-52 I echo Mark comments.Â  The only time you should be doing pulling bits off your airplane is for routine maintenance or when something is busted.

 

 Pulling cylinders for an inspection is, in my opinion, not a smart idea.Â  A good analogy would be open heart surgery to have a look at your heart valves!Â  You are introducing the risk of infant mortality unnecessarily.

 

 Do a leak down test and bung a boroscope into each cylinder and have a look around that way.Â  A failing valve will stand out a mile if you know what you are looking for.Â  There is a very good series of videos on Youtube by a guy called Mike Busch (Savy Aviator), one on valves.Â  While Mike has much bigger balls than I do when it comes to maintenance his principles are sound and he gives good and well thought out advice.

 

 The moral of my story is the old saying.... If it is not broke, don't fix it!

 

 Chris

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=481735#481735

 

 

 

 

 

 

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dsavarese0812(at)bellsout
Guest

Posted: Wed Jul 18, 2018 1:44 pm Post subject: Valves inspection

Concur 110% with Walt.  Add it to the oil religiously.  I would also add a quart or even 2 to the oil and run the engine a couple of hours.  You'll be amazed at how MMO will remove the varnish on the valve/valve guide which is causing the sticking valve.

Dennis

       From: Looigi <cdoburton(at)gmail.com>

 To: yak-list(at)matronics.com 

 Sent: Wednesday, July 18, 2018 4:39 PM

 Subject: Re: Valves inspection

--> Yak-List message posted by: "Looigi" <cdoburton(at)gmail.com (cdoburton(at)gmail.com)>

Hi Javier,

As an A&P who has my own yak-52 I echo Mark comments.  The only time you should be doing pulling bits off your airplane is for routine maintenance or when something is busted.

Pulling cylinders for an inspection is, in my opinion, not a smart idea.  A good analogy would be open heart surgery to have a look at your heart valves!  You are introducing the risk of infant mortality unnecessarily.

Do a leak down test and bung a boroscope into each cylinder and have a look around that way.  A failing valve will stand out a mile if you know what you are looking for.  There is a very good series of videos on Youtube by a guy called Mike Busch (Savy Aviator), one on valves.  While Mike has much bigger balls than I do when it comes to maintenance his principles are sound and he gives good and well thought out advice.

The moral of my story is the old saying.... If it is not broke, don't fix it!

Chris

Read this topic online here:

http://forums.matronics.com/viewtopic.php?p=481735#481735

 Archive Search & Download, 7-Day Browse, Chat, FAQ,

http://www.matronics.com/Np;              - MATRONICS WEB FORUMS -

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dsavarese0812(at)bellsout
Guest

Posted: Wed Jul 18, 2018 4:26 pm Post subject: Valves inspection

I meant add it to the fuel religiously. Add a coding to instructions on the container. Dennis



Sent from my iPad



On Jul 18, 2018, at 5:44 PM, A. Dennis Savarese <dsavarese0812(at)bellsouth.net (dsavarese0812(at)bellsouth.net)> wrote:

 	  Quote: 	
		  Concur 110% with Walt.  Add it to the oil religiously.  I would also add a quart or even 2 to the oil and run the engine a couple of hours.  You'll be amazed at how MMO will remove the varnish on the valve/valve guide which is causing the sticking valve.

Dennis



       From: Looigi <cdoburton(at)gmail.com (cdoburton(at)gmail.com)>

 To: yak-list(at)matronics.com (yak-list(at)matronics.com) 

 Sent: Wednesday, July 18, 2018 4:39 PM

 Subject: Re: Valves inspection

  

 

--> Yak-List message posted by: "Looigi" <cdoburton(at)gmail.com (cdoburton(at)gmail.com)>



Hi Javier,



As an A&P who has my own yak-52 I echo Mark comments.  The only time you should be doing pulling bits off your airplane is for routine maintenance or when something is busted.



Pulling cylinders for an inspection is, in my opinion, not a smart idea.  A good analogy would be open heart surgery to have a look at your heart valves!  You are introducing the risk of infant mortality unnecessarily.



Do a leak down test and bung a boroscope into each cylinder and have a look around that way.  A failing valve will stand out a mile if you know what you are looking for.  There is a very good series of videos on Youtube by a guy called Mike Busch (Savy Aviator), one on valves.  While Mike has much bigger balls than I do when it comes to maintenance his principles are sound and he gives good and well thought out advice.



The moral of my story is the old saying.... If it is not broke, don't fix it!



Chris



Read this topic online here:



http://forums.matronics.com/viewtopic.php?p=481735#481735



 Archive Search & Download, 7-Day Browse, Chat, FAQ,



http://www.matronics.com/Np;              - MATRONICS WEB FORUMS -

<;  --> http:/nbsp;             - NEW MATRONICS LIST WIKI -matronics.com/" target="_blank">http://wiki.matronics.com



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Viperdoc

Joined: 19 Apr 2014
Posts: 484
Location: 08A

Posted: Thu Jul 19, 2018 5:23 am Post subject: Valves inspection

Spot on Brother! If it ainâ€™t broke donâ€™t 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



[quote] On Jul 18, 2018, at 3:03 PM, Bitterlich, Mark G CIV NAVAIR, WD <mark.bitterlich(at)navy.mil> wrote:

 

 

 

 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 typically found during a differential compression test, where air leaks through the exhaust valve into the exhaust pipes and is easy to detect just by listening.  Another viable method is to inspect the valves with a type of borescope or miniature camera, which today are pretty cheap.

 

 Second, I have never in my life heard of a person suggesting that they remove the valve springs, which means also removing the valve keeps, which can 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 is that doing this at a yearly Conditional Inspection without proof of any problem to begin with is way way over the top.  As far as "removing the valve to clean the shaft", that means pulling the whole cylinder off.  There has been more than one person that has dropped small parts down into the engine 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 many 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 engine.

 

 It is not necessary to remove valve keepers and springs and attempt to judge valve movement during a Conditional Inspection.  It is not called for in 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 before it makes it's way into the valve guide.  Regardless a borescope will show it in great detail and should be considered as a first step way before taking apart valves or cylinders.

 

 Mark

 

 

 --

_________________
Viperdoc

cjpilot710(at)aol.com
Guest

Posted: Sun Jul 29, 2018 8:05 am Post subject: Valves inspection

Stuck here in Greene County regional airport just south of Dayton, Ohio with 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 like I'll need to replace the gear valve.  More trouble shooting to do. 

 

  Jim "Pappy" Goolsby

 

 

  --

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