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Jammed engine

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rob10(at)tlb.sympatico.ca
Guest

Posted: Tue Sep 06, 2011 12:36 pm Post subject: Jammed engine

Hi listers,  

I have a problem with my 912 engine. I did not use the plane for the last month. I tried to start it this morning but couln’t get the prop to turn at all. Tried by hand but it is completely jammed.   

I was able to turn it backward so I did for one stroke and tried again forward but nothing could turn any forward than before.  

Anyone had that problem before? My engine has 18 years but only 300 hours  

Jack  

Model 4   

       [quote][b]

gpabruce(at)gmail.com
Guest

Posted: Tue Sep 06, 2011 12:58 pm Post subject: Jammed engine

You may have a hydraulic lock or a stuck valve meaning you may have gotten water or oil in a cylinder but how could that happen? Has it been exposed to rain or flooding unprotected? I'm only guessing at one of many possibilities. I would pull all the plugs and see if the engine can be turned through very carefully. That would eliminate this possibility. There are other possibilities but none of them good. Like a broken valve for instance. It could be a stuck valve. I would start by pulling the plugs, trying to rotate the crank and then do a visual inspection of the internal cylinders.  



Bruce 



On Tue, Sep 6, 2011 at 1:33 PM, rosane <rob10(at)tlb.sympatico.ca (rob10(at)tlb.sympatico.ca)> wrote:

[quote]              

Hi listers,  

I have a problem with my 912 engine. I did not use the plane for the last month. I tried to start it this morning but couln’t get the prop to turn at all. Tried by hand but it is completely jammed.   

I was able to turn it backward so I did for one stroke and tried again forward but nothing could turn any forward than before.  

Anyone had that problem before? My engine has 18 years but only 300 hours  

Jack  

Model 4   

        	  Quote: 	
		  



arget="_blank">http://www.matronics.com/Navigator?Kitfox-List

tp://forums.matronics.com

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[b]

lcfitt(at)sbcglobal.net
Guest

Posted: Tue Sep 06, 2011 2:09 pm Post subject: Jammed engine

Jack,

 This is not uncommon.  With the high mounted oil  tank, it is a regular phenomenon for the oil to siphon from the tank into the  crank.  If the angles are just right, there can be oil introduced into a  cylinder producing the "Hydraulic lock".  The recommendation to remove the  bottom spark plugs to drain the oil is the correct solution.  One thing I  have found is that the oil will siphon most quickly when it is warm immediately  after a flight.  If after complete cool down, I then burp the tank by  hand propping until the air sound is heard in the tank vent, it will go a week  or more with very little oil siphoning.  This should get you through a  month of non flying.

 Lowell

  



  From: rosane (rob10(at)tlb.sympatico.ca) 

 Sent: Tuesday, September 06, 2011 1:33 PM

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

 Subject: Jammed engine

 



  

Hi  listers, 

I have a problem with my 912 engine.  I did not use the plane for the last month. I tried to start it this morning but  couln’t get the prop to turn at all. Tried by hand but it is completely jammed.   

I was able to turn it backward so I  did for one stroke and tried again forward but nothing could turn any forward  than before. 

Anyone had that problem before? My  engine has 18 years but only 300 hours 

Jack 

Model 4  

[quote]



href="http://www.matronics.com/Navigator?Kitfox-List">http://www.matronhref="http://forums.matronics.com">http://forums.matronics.com

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[b]

Roger Lee

Joined: 10 Jan 2006
Posts: 1464
Location: Tucson, Az.

Posted: Tue Sep 06, 2011 5:05 pm Post subject: Re: Jammed engine

Depending on the oil filter you use and where the oil tank is located (higher than recommended) then oil drain back can happen and lock up a cylinder. Pull the bottom plugs and see if fluid drains and if you can then turn the prop. 

See the article I wrote on the Rotax Owners website. This is why the oil filter was re-designed. It now does a better job of preventing this. If you can't read it on the Rotax Owners forum then you can see it on the at www.ctflier.com on a forum blog. The new Rotax oil filter has some major changes.

There shouldn't be anything else that would cause this. Even a stuck valve should let the prop turn.

_________________
Roger Lee
Tucson, Az.
Rotax Instructor & Rotax IRC
Light Sport Repairman
Home 520-574-1080 TRY HOME FIRST
Cell 520-349-7056

gpabruce(at)gmail.com
Guest

Posted: Tue Sep 06, 2011 5:34 pm Post subject: Jammed engine

A Hydraulic lock is easy to find. However a stuck valve (stuck in the closed position) which is more probable is a little harder as it can be any valve stuck closed (stuck open won't do it unless it's an interference type engine and I don't know about a 912) If it is a stuck valve, the engine should rotate backwards slightly less than two full revolutions whereupon it should stop again. (be careful not to force it) However with a hydraulic lock, by rotating the prop backwards, it should clear the hydraulic lock forcing the liquid out the valve ports, the same as removing the plugs. The question is, how did it get that much oil or water in the cylinder to give it a hydraulic lock? If it is water cooled, you may have a bad head gasket or cracked head. If it is oil, you have an interesting problem as that shouldn't happen. If I was there, these are easy to trouble shoot but in lieu of that, you must provide feedback. 



Thanks,

Bruce



On Tue, Sep 6, 2011 at 6:05 PM, Roger Lee <ssadiver1(at)yahoo.com (ssadiver1(at)yahoo.com)> wrote:

 [quote]--> Kitfox-List message posted by: "Roger Lee" <ssadiver1(at)yahoo.com (ssadiver1(at)yahoo.com)>

  

 Depending on the oil filter you use and where the oil tank is located (higher than recommended) then oil drain back can happen and lock up a cylinder. Pull the bottom plugs and see if fluid drains and if you can then turn the prop.

  See the article I wrote on the Rotax Owners website. This is why the oil filter was re-designed. It now does a better job of preventing this. If you can't read it on the Rotax Owners forum then you can see it on the at www.ctflier.com on a forum blog. The new Rotax oil filter has some major changes.

  

 --------

 Roger Lee

 Tucson, Az.

 Light Sport Repairman - Maintenance Rated

 Rotax Repair Center - Heavy Maint. Rated

 Home [url=tel:520-574-1080]520-574-1080[/url]  TRY HOME FIRST

 Cell [url=tel:520-349-7056]520-349-7056[/url]

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=351603#351603

 

 

 

 

 

 

 

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 [b]

gpabruce(at)gmail.com
Guest

Posted: Tue Sep 06, 2011 5:44 pm Post subject: Jammed engine

Roger, 



How does the oil get into the cylinder even if it drains back? Shouldn't it free flow into the crankcase? Are you saying it's filling the rocker boxes and leaking through the valve guides? Don't the rocker arms get their oil via the main oil gallery, the lifters, the push rods and back down the push rod tubes? How else is it getting in there and ultimately getting into the cylinders? I'm not at all familiar with the Rotax 4 stroke engine oil systems so maybe you are right but it sounds strange.  



Please help me with this. 

Bruce   



On Tue, Sep 6, 2011 at 6:05 PM, Roger Lee <ssadiver1(at)yahoo.com (ssadiver1(at)yahoo.com)> wrote:

 [quote]--> Kitfox-List message posted by: "Roger Lee" <ssadiver1(at)yahoo.com (ssadiver1(at)yahoo.com)>

  

 Depending on the oil filter you use and where the oil tank is located (higher than recommended) then oil drain back can happen and lock up a cylinder. Pull the bottom plugs and see if fluid drains and if you can then turn the prop.

  See the article I wrote on the Rotax Owners website. This is why the oil filter was re-designed. It now does a better job of preventing this. If you can't read it on the Rotax Owners forum then you can see it on the at www.ctflier.com on a forum blog. The new Rotax oil filter has some major changes.

  

 --------

 Roger Lee

 Tucson, Az.

 Light Sport Repairman - Maintenance Rated

 Rotax Repair Center - Heavy Maint. Rated

 Home [url=tel:520-574-1080]520-574-1080[/url]  TRY HOME FIRST

 Cell [url=tel:520-349-7056]520-349-7056[/url]

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=351603#351603

 

 

 

 

 

 

 

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 [b]

lcfitt(at)sbcglobal.net
Guest

Posted: Tue Sep 06, 2011 6:14 pm Post subject: Jammed engine

The Rotax engine is in numerous aircraft models and some  installations have issues that are very specific to the aircraft in  question.  This is a case in point.  Changes in the engine mount  on subsequent Kitfox models have eliminated this issue as well as the need to  Burp the engine to return the oil to the remote oil tank before  start.

  

 As mentioned before, the Model IV (and earlier)  with the oil tank mounted behind the engine and above the preferred crank level  position has a history of siphoning all the oil out of the tank and into the  crank case.  This is a dry sump system with relatively little capacity for  the oil in the crankcase.  So with the horizontally opposed engine oil  can  seep  from the crankcase into the cylinders past the piston rings  and cause hydraulic lock.  It is not that uncommon.  It has nothing to  do with the heads or oil gallery, but just pure and simple gravity.   Another thing that bears mentioning, Rotax strongly recommends never rotating  the prop backwards.  It can introduce air into the lubricating system  and negatively affect the lifters.  If rotated backwards, they recommend a  rather inconvenient process to remove the air before engine run.  in almost  20 years of monitoring this and other forums and 900 hours on my own 912, I have  never heard of water in the cylinders of a Rotax engine.

  

 My take on the problem, first check the historically  most common cause.  If the solution is not there, go further.

 Lowell

  



  From: b d (gpabruce(at)gmail.com) 

 Sent: Tuesday, September 06, 2011 6:40 PM

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

 Subject: Re: Re: Jammed engine

 



Roger,   



 How does the oil get into the cylinder even if it drains back? Shouldn't it  free flow into the crankcase? Are you saying it's filling the rocker boxes and  leaking through the valve guides? Don't the rocker arms get their oil via the  main oil gallery, the lifters, the push rods and back down the push rod tubes?  How else is it getting in there and ultimately getting into the cylinders? I'm  not at all familiar with the Rotax 4 stroke engine oil systems so maybe you are  right but it sounds strange.   



 Please help me with this. 

 



 Bruce   



 On Tue, Sep 6, 2011 at 6:05 PM, Roger Lee <ssadiver1(at)yahoo.com (ssadiver1(at)yahoo.com)> wrote:

 [quote]--> Kitfox-List message posted by: "Roger Lee" <ssadiver1(at)yahoo.com (ssadiver1(at)yahoo.com)>



Depending    on the oil filter you use and where the oil tank is located (higher than    recommended) then oil drain back can happen and lock up a cylinder. Pull the    bottom plugs and see if fluid drains and if you can then turn the prop.

See    the article I wrote on the Rotax Owners website. This is why the oil filter    was re-designed. It now does a better job of preventing this. If you can't    read it on the Rotax Owners forum then you can see it on the at www.ctflier.com on a forum    blog. The new Rotax oil filter has some major    changes.



--------

Roger Lee

Tucson, Az.

Light Sport Repairman    - Maintenance Rated

Rotax Repair Center - Heavy Maint. Rated

Home [url=tel:520-574-1080]520-574-1080[/url]  TRY HOME    FIRST

Cell [url=tel:520-349-7056]520-349-7056[/url]





Read this topic    online here:



http://forums.matronics.com/viewtopic.php?p=351603#351603



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[b]

Roger Lee

Joined: 10 Jan 2006
Posts: 1464
Location: Tucson, Az.

Posted: Tue Sep 06, 2011 9:28 pm Post subject: Re: Jammed engine

Hi Bruce,



What Lowell said. He is spot on.

_________________
Roger Lee
Tucson, Az.
Rotax Instructor & Rotax IRC
Light Sport Repairman
Home 520-574-1080 TRY HOME FIRST
Cell 520-349-7056

gpabruce(at)gmail.com
Guest

Posted: Tue Sep 06, 2011 9:52 pm Post subject: Jammed engine

Lowell,



Thanks for the info. However what I was referring to was recip engines in

general, from the smallest

engine<http://www.google.com/search?hl=en&sugexp=gsis,i18n%3Dtrue&cp=29&gs_id=2&xhr=t&q=smallest+reciprocating+engine&qe=c21hbGxlc3QgcmVjaXByb2NhdGluZyBlbmdpbmU&qesig=um2ixYW4QkiuNLY42mwMhA&pkc=AFgZ2tlpJVVpmi4_Xgr40PhpCs-i_4thn2M1kddUNtlIA1yM_sRXDJVhJUDh76tW9ECE64dzxxn8zvRR2IRlNY3ZPN0L2npZrg&safe=off&gs_sm=&gs_upl=&bav=on.2,or.r_gc.r_pw.&biw=1639&bih=800&um=1&ie=UTF-8&tbm=isch&source=og&sa=N&tab=wi#um=1&hl=en&safe=off&tbm=isch&sa=1&q=smallest+model+airplane+engine&oq=smallest+model+airplane+engine&aq=f&aqi=&aql=&gs_sm=s&gs_upl=51792l62646l0l65368l22l22l0l0l0l6l298l4435l0.12.10l22l0&bav=on.2,or.r_gc.r_pw.&fp=4c9ea064eff50979&biw=1639&bih=800>to

the

largest<http://www.google.com/search?hl=en&sugexp=gsis,i18n%3Dtrue&cp=29&gs_id=2&xhr=t&q=smallest+reciprocating+engine&qe=c21hbGxlc3QgcmVjaXByb2NhdGluZyBlbmdpbmU&qesig=um2ixYW4QkiuNLY42mwMhA&pkc=AFgZ2tlpJVVpmi4_Xgr40PhpCs-i_4thn2M1kddUNtlIA1yM_sRXDJVhJUDh76tW9ECE64dzxxn8zvRR2IRlNY3ZPN0L2npZrg&safe=off&gs_sm=&gs_upl=&bav=on.2,or.r_gc.r_pw.&biw=1639&bih=800&um=1&ie=UTF-8&tbm=isch&source=og&sa=N&tab=wi#um=1&hl=en&safe=off&tbm=isch&sa=1&q=largest+piston+engine&oq=largest+piston+engine&aq=f&aqi=&aql=&gs_sm=s&gs_upl=138172l150012l2l153278l17l16l2l0l0l2l234l2353l0.12.2l14l0&bav=on.2,or.r_gc.r_pw.&fp=4c9ea064eff50979&biw=1639&bih=800>

such

as the old R-4360 radial engines <http://Pratt & Whitney R-4360 Wasp Major>,

Worlds Largest Steam Engine <http://www.eng.mu.edu/corlissg/gc_engine.html>

gpabruce(at)gmail.com
Guest

Posted: Tue Sep 06, 2011 10:09 pm Post subject: Jammed engine

Other sites:

Located near Smithville, TX The Monarch Corliss Steam Engine  



And 

 



 R-4360 radial engine

 





 Douglas C-124 Globemaster II

 Boeing B-50 Superfortress



On Tue, Sep 6, 2011 at 10:50 PM, b d <gpabruce(at)gmail.com (gpabruce(at)gmail.com)> wrote:

 [quote]Lowell, 



Thanks for the info. However what I was referring to was recip engines in general, from the smallest engine to the largest such as the old R-4360 radial engines, Worlds Largest Steam Engine. Your method of troubleshooting is fine for one particular engine if you know those idiosyncrasies. Personally if that is a normal event with a 912, I would call it poor and unacceptable engineering. Normally and A&P deals with many different types of engines and there are certain procedures that apply to all reciprocating internal combustion engines including the 912 and that's very simply what I was describing. 

  



I am not doubting whether you're right or wrong and I appreciate what you are saying but that is only one way of skinning a cat. Since my method is fool proof, checks everything, because mine depends on good old mechanical logic and standard practice that applies to all recips where this other method depends on "word of mouth and hearsay" which could be as dangerous as superstition and old wives tales. If I had paid as much money as I hear they want for a 912, I would expect better and I would not be very happy to find out that at any given moment, I may have to go to all the time and trouble to clear the engine that is described herein before I am able to fly. I don't know about other people, maybe they have more time and money and patience than I do but I think not hence the question from the plane owner. I think you are saying it requires a modification if one doesn't want to experience this over and over is that correct?

  



Regards,

Bruce

On Tue, Sep 6, 2011 at 7:11 PM, Lowell Fitt <lcfitt(at)sbcglobal.net (lcfitt(at)sbcglobal.net)> wrote:

   	  Quote: 	
		       The Rotax engine is in numerous aircraft models and some  installations have issues that are very specific to the aircraft in  question.  This is a case in point.  Changes in the engine mount  on subsequent Kitfox models have eliminated this issue as well as the need to  Burp the engine to return the oil to the remote oil tank before  start.

  

 As mentioned before, the Model IV (and earlier)  with the oil tank mounted behind the engine and above the preferred crank level  position has a history of siphoning all the oil out of the tank and into the  crank case.  This is a dry sump system with relatively little capacity for  the oil in the crankcase.  So with the horizontally opposed engine oil  can  seep  from the crankcase into the cylinders past the piston rings  and cause hydraulic lock.  It is not that uncommon.  It has nothing to  do with the heads or oil gallery, but just pure and simple gravity.   Another thing that bears mentioning, Rotax strongly recommends never rotating  the prop backwards.  It can introduce air into the lubricating system  and negatively affect the lifters.  If rotated backwards, they recommend a  rather inconvenient process to remove the air before engine run.  in almost  20 years of monitoring this and other forums and 900 hours on my own 912, I have  never heard of water in the cylinders of a Rotax engine.

  

 My take on the problem, first check the historically  most common cause.  If the solution is not there, go further.

 Lowell

  



  From: b d (gpabruce(at)gmail.com) 

 Sent: Tuesday, September 06, 2011 6:40 PM

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

 Subject: Re: Re: Jammed engine

 



Roger,   



 How does the oil get into the cylinder even if it drains back? Shouldn't it  free flow into the crankcase? Are you saying it's filling the rocker boxes and  leaking through the valve guides? Don't the rocker arms get their oil via the  main oil gallery, the lifters, the push rods and back down the push rod tubes?  How else is it getting in there and ultimately getting into the cylinders? I'm  not at all familiar with the Rotax 4 stroke engine oil systems so maybe you are  right but it sounds strange.   



 Please help me with this. 

 



 

Bruce   



 On Tue, Sep 6, 2011 at 6:05 PM, Roger Lee <ssadiver1(at)yahoo.com (ssadiver1(at)yahoo.com)> wrote:

 

 	  Quote: 	
		  --> Kitfox-List message posted by: "Roger Lee" <ssadiver1(at)yahoo.com (ssadiver1(at)yahoo.com)>

  

Depending    on the oil filter you use and where the oil tank is located (higher than    recommended) then oil drain back can happen and lock up a cylinder. Pull the    bottom plugs and see if fluid drains and if you can then turn the prop.

See    the article I wrote on the Rotax Owners website. This is why the oil filter    was re-designed. It now does a better job of preventing this. If you can't    read it on the Rotax Owners forum then you can see it on the at www.ctflier.com on a forum    blog. The new Rotax oil filter has some major    changes.



--------

Roger Lee

Tucson, Az.

Light Sport Repairman    - Maintenance Rated

Rotax Repair Center - Heavy Maint. Rated

Home [url=tel:520-574-1080]520-574-1080[/url]  TRY HOME    FIRST

Cell [url=tel:520-349-7056]520-349-7056[/url]





Read this topic    online here:



http://forums.matronics.com/viewtopic.php?p=351603#351603

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 [b]

Dick Maddux

Joined: 24 Jun 2008
Posts: 516
Location: Milton, Fl

Posted: Wed Sep 07, 2011 3:50 am Post subject: Jammed engine

Bruce,

  Lowell is right on the mark with his explanation of the hydraulic  lock that can occur with the 912. It is taught in Lockwoods 912 service class  when reviewing the oil system. This is one of the two reasons you "burp" the  engine .(ie: check for hydraulic lock) The other is to check the oil level. It  is the nature of the engine depending on the oil tank location and I dare say  would occur with a Continental engine,as an example, if you could put the oil  tank in a high position.

  Radial engines were /are prone to this same condition.

  I have never had a hydraulic lock in my 912 BUT as I have a high oil  tank I always expect it. I have let the engine sit for a month and there will be  no oil on the dip stick but again,no hydraulic lock. I am going to try the new  oil filter to see if it will stop the siphoning as it is suppose to. However it  is a little longer and I have very little clearance on my exhaust pipe when  removing/installing so I hope it will fit !

                                                                  Dick Maddux

                                                                  Fox 4

                                                                  Milton,Fl

  

 [quote][b]

gpabruce(at)gmail.com
Guest

Posted: Wed Sep 07, 2011 3:00 pm Post subject: Jammed engine

Thank you young man,

I have no clue what conversation you are referring to because there is no reference. I may agree with Mr. Lowell too if I only knew what this is about.

 With that said, I do appreciate your perception and loyalty. Your vote is so noted for whatever that is worth.  



 ;-)



Bruce  Seasoned A&P ex-military, pilot, flight engineer, GA and Commercial Airlines (not limited to light sport). . . . and old, grouchy and not PC. "Been there and done it and don't have to vote on it!" 

   



On Tue, Sep 6, 2011 at 10:28 PM, Roger Lee <ssadiver1(at)yahoo.com (ssadiver1(at)yahoo.com)> wrote:

 [quote]--> Kitfox-List message posted by: "Roger Lee" <ssadiver1(at)yahoo.com (ssadiver1(at)yahoo.com)>

   

 Hi Bruce,

 

 What Lowell said. He is spot on.

 

 --------

 Roger Lee

 Tucson, Az.

 Light Sport Repairman - Maintenance Rated

 Rotax Repair Center - Heavy Maint. Rated

 Home [url=tel:520-574-1080]520-574-1080[/url]  TRY HOME FIRST

 Cell [url=tel:520-349-7056]520-349-7056[/url]

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=351631#351631

 

 

 

 

 

 

 

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