Matronics Email Lists :: View topic

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

Yak 18T

Matronics Email Lists Forum Index -> Yak-List

View previous topic :: View next topic

Author Message

bigglesusa

Joined: 29 Apr 2009
Posts: 57
Location: Franklin VA

Posted: Tue Jun 22, 2010 3:35 pm Post subject: Yak 18T

After standing almost abandoned for 9 years and after 18 months rebuild our Yak 18T took to the skies for first time today and behaved almost perfectly. One or two small niggles which we would appreciate comments on by the more experienced members of this forum:  

Tacho % Power – needle fluctuates each side of ? correct figure  

With equal fuel added  left hand tank gauge shows much less than RH tank  

What is correct nomination of the manifold pressure gauge – is it boost please ?  

She is soon going to new owner in Washington State as we return to UK.  Terry Beezhold is looking for someone to fly with hiom from Franklin, Virginia (VA) to Washington fairly soon.  

All contact to Terry at - Terry & Joni Beezhold [tjbeezhold(at)comcast.net] please.  Quite a trip !  

Thanks everybody.  

       [quote][b]

_________________
'Le temps mange la vie'

bigglesusa

Joined: 29 Apr 2009
Posts: 57
Location: Franklin VA

Posted: Thu Jun 24, 2010 4:48 am Post subject: Yak 18T

My Yak 18T last flew when she was in Russia.  Rather  a shock for her to face the Summer heat of Virginia this week – 100 to 105 F.  We have had some problems with high CHT when climbing and it has been hard to reach figures below 200 C (orange sector).  Has anybody ideas of how we can keep in the green with these ambient temps. Thanks.  

       [quote][b]

_________________
'Le temps mange la vie'

rick(at)rvairshows.com
Guest

Posted: Thu Jun 24, 2010 5:01 am Post subject: Yak 18T

Use a larger MT type prop/spinner to duct the air better.  GT propellers just came out with a similar size spinner for the v530 prop that should also do the trick. It will also allow a proper dynamic balance of this prop.Rick Volker

On Jun 24, 2010, at 8:48 AM, SC wrote:

[quote]     st1\:*{behavior:url(#default#ieooui) }  <![endif]-->         

My Yak 18T last flew when she was in Russia.  Rather  a shock for her to face the Summer heat of Virginia this week – 100 to 105 F.  We have had some problems with high CHT when climbing and it has been hard to reach figures below 200 C (orange sector).  Has anybody ideas of how we can keep in the green with these ambient temps. Thanks.  

        	  Quote: 	
		  



href="http://www.matronics.com/Navigator?Yak-List">http://www.matronics.com/Navigator?Yak-List

href="http://forums.matronics.com/">http://forums.matronics.com

href="http://www.matronics.com/contribution">http://www.matronics.com/contribution



	


[b]

richard.goode(at)russiana
Guest

Posted: Thu Jun 24, 2010 5:04 am Post subject: Yak 18T

You need to change the compensating jet in the carburettor.  

I suspect that 80% of owners do not even know what this is,let alone how to change it which is very simple-5 minutes only.  

In fact it is a good idea to change between summer and winter,particularly when there is a big temperature change between them.  

Alfonz at wlac has sets of the jets.    

Richard Goode Aerobatics  

Rhodds Farm  

Lyonshall  

Herefordshire  

HR5 3LW  

United Kingdom  

   

Tel:  +44 (0) 1544 340120  

Fax:  +44 (0) 1544 340129  

www.russianaeros.com  

        

  

From: owner-yak-list-server(at)matronics.com [mailto:owner-yak-list-server(at)matronics.com] On Behalf Of SC

 Sent: 24 June 2010 13:48

 To: yak-list(at)matronics.com

 Subject: Yak 18T  

  

   

My Yak 18T last flew when she was in Russia.  Rather  a shock for her to face the Summer heat of Virginia this week – 100 to 105 F.  We have had some problems with high CHT when climbing and it has been hard to reach figures below 200 C (orange sector).  Has anybody ideas of how we can keep in the green with these ambient temps. Thanks.   	  Quote: 	
		    http://www.matronics.com/Navigator?Yak-List 	
0 	  Quote: 	
		   	
1 	  Quote: 	
		   	
2 	  Quote: 	
		   	
3 	  Quote: 	
		   	
4 	  Quote: 	
		   	
5 	  Quote: 	
		   	
6 	  Quote: 	
		   	
7 	  Quote: 	
		   	
8 	  Quote: 	
		   	
9

      --------------------------------------------------  This message has been scanned for viruses and   dangerous content by the Invictawiz MailScanner   and is believed to be clean.  http://www.invictawiz.com/  --------------------------------------------------    [quote][b]

dsavarese0812(at)bellsout
Guest

Posted: Thu Jun 24, 2010 5:27 am Post subject: Yak 18T

Has anyone actually been able to purchase one of the GT  propeller larger spinners?  I know they are being advertised.  But no  one has them and from what I've been able to determine, no dealer has been able  to get them either.

 Dennis

  

 [quote]   ---

dsavarese0812(at)bellsout
Guest

Posted: Thu Jun 24, 2010 5:39 am Post subject: Yak 18T

200 degrees C is certainly not unusual during climb out when  it's 100 degrees F outside and the M14 manual permits continuous operation at  that temperature.   What temperature does it run at when in straight  and level cruise flight?  

  

 IF when you change the compensating jet you feel the engine  hesitate or cough when pushing the power up, (gets your attention, particularly  on short final), you will need to change to a smaller jet.  If  I'm not mistaken, the smallest jet in the set is .9 mm and many times even  installing the .9 mm jet does not stop the hesitation on power  up.

  

 Richard is right though.  It only takes 5 minutes to  change the jet.  And 10 minutes to re-safety wire the plug.   )

 Dennis

 [quote]   ---

bigglesusa

Joined: 29 Apr 2009
Posts: 57
Location: Franklin VA

Posted: Thu Jun 24, 2010 5:53 am Post subject: Yak 18T

Thanks Dennis  -  any suggestions as to size I should start with and range of jets I should have.  When we got to 7000ft CHT just about got into green and then we had to close oil cooler door partially to keep oil temp in range  

Steve  

         

  

From: owner-yak-list-server(at)matronics.com [mailto:owner-yak-list-server(at)matronics.com] On Behalf Of A. Dennis Savarese

 Sent: Thursday, June 24, 2010 9:16 AM

 To: yak-list(at)matronics.com

 Subject: Re: Yak 18T  

  

     

200 degrees C is certainly not unusual during climb out when it's 100 degrees F outside and the M14 manual permits continuous operation at that temperature.   What temperature does it run at when in straight and level cruise flight?    

    

   

    

IF when you change the compensating jet you feel the engine hesitate or cough when pushing the power up, (gets your attention, particularly on short final), you will need to change to a smaller jet.  If I'm not mistaken, the smallest jet in the set is .9 mm and many times even installing the .9 mm jet does not stop the hesitation on power up.  

    

   

    

Richard is right though.  It only takes 5 minutes to change the jet.  And 10 minutes to re-safety wire the plug.  )  

    

Dennis  

  [quote]    

---

_________________
'Le temps mange la vie'

richard.goode(at)russiana
Guest

Posted: Thu Jun 24, 2010 6:25 am Post subject: Yak 18T

The jets go from 0.9mm to 2.1mm.Of course most in use are between 1.2 and 1.9.  

You can only try by checking what you have,then trying a jet 1 or 2 sizes smaller.  

Since they are compensating jets,a smaller jet give a richer mixture.  

   

     

Richard Goode Aerobatics  

Rhodds Farm  

Lyonshall  

Herefordshire  

HR5 3LW  

United Kingdom  

   

Tel:  +44 (0) 1544 340120  

Fax:  +44 (0) 1544 340129  

www.russianaeros.com  

        

  

From: owner-yak-list-server(at)matronics.com [mailto:owner-yak-list-server(at)matronics.com] On Behalf Of SC

 Sent: 24 June 2010 14:53

 To: yak-list(at)matronics.com

 Subject: RE: Yak 18T  

  

   

Thanks Dennis  -  any suggestions as to size I should start with and range of jets I should have.  When we got to 7000ft CHT just about got into green and then we had to close oil cooler door partially to keep oil temp in range  

Steve  

         

  

From: owner-yak-list-server(at)matronics.com [mailto:owner-yak-list-server(at)matronics.com] On Behalf Of A. Dennis Savarese

 Sent: Thursday, June 24, 2010 9:16 AM

 To: yak-list(at)matronics.com

 Subject: Re: Yak 18T  

  

     

200 degrees C is certainly not unusual during climb out when it's 100 degrees F outside and the M14 manual permits continuous operation at that temperature.   What temperature does it run at when in straight and level cruise flight?    

    

   

    

IF when you change the compensating jet you feel the engine hesitate or cough when pushing the power up, (gets your attention, particularly on short final), you will need to change to a smaller jet.  If I'm not mistaken, the smallest jet in the set is .9 mm and many times even installing the .9 mm jet does not stop the hesitation on power up.  

    

   

    

Richard is right though.  It only takes 5 minutes to change the jet.  And 10 minutes to re-safety wire the plug.  )  

    

Dennis  

  [quote]    

---

rick(at)rvairshows.com
Guest

Posted: Thu Jun 24, 2010 6:42 am Post subject: Yak 18T

They have just become available in the last week or so. I have not seen one yet, but have looked at the design.  Same general size as large MT spinner for MTV9. There must be at least 20 orders in place for them at this time.  Rick Volker

On Jun 24, 2010, at 9:19 AM, A. Dennis Savarese wrote:

[quote]  Has anyone actually been able to purchase one of the GT  propeller larger spinners?  I know they are being advertised.  But no  one has them and from what I've been able to determine, no dealer has been able  to get them either.

 Dennis

  

 [quote]   ---

dsavarese0812(at)bellsout
Guest

Posted: Thu Jun 24, 2010 10:24 am Post subject: Yak 18T

Steve,

 If you are not experiencing any hesitation on power up when  the engine is at operating temperature, you could increase the jet size by  .1mm.  Basically, you need to find out what size is in the carburetor  first.  Then keep increasing the jet size by .1 mm while being cognizant of  the fact that you may begin to experience the hesitation I previously  mentioned when you push the power up quickly.

  

 Another question would be, how do you know the instrument  reading is accurate?  What cylinder is the temperature probe installed  on?

 Dennis

  

  

 ---

dsavarese0812(at)bellsout
Guest

Posted: Thu Jun 24, 2010 10:35 am Post subject: Yak 18T

Sorry...I meant to say DECREASE the jet size by .1 mm.   Age has crept in.

 Dennis

 [quote]   ---

bigglesusa

Joined: 29 Apr 2009
Posts: 57
Location: Franklin VA

Posted: Thu Jun 24, 2010 10:49 am Post subject: Yak 18T

Bottom left cyl ? Dennis  

         

  

From: owner-yak-list-server(at)matronics.com [mailto:owner-yak-list-server(at)matronics.com] On Behalf Of A. Dennis Savarese

 Sent: Thursday, June 24, 2010 2:17 PM

 To: yak-list(at)matronics.com

 Subject: Re: Yak 18T  

  

     

Steve,  

    

If you are not experiencing any hesitation on power up when the engine is at operating temperature, you could increase the jet size by .1mm.  Basically, you need to find out what size is in the carburetor first.  Then keep increasing the jet size by .1 mm while being cognizant of the fact that you may begin to experience the hesitation I previously mentioned when you push the power up quickly.  

    

   

    

Another question would be, how do you know the instrument reading is accurate?  What cylinder is the temperature probe installed on?  

    

Dennis  

    

   

    

   

    

---

_________________
'Le temps mange la vie'

mark.bitterlich(at)navy.m
Guest

Posted: Thu Jun 24, 2010 10:54 am Post subject: Yak 18T

Is all this being based on a climb on a 90 degree (F) plus day, where

the cylinder head temps got into the yellow during a high power climb? 



I mean heck.... If so, that is pretty much a normal indication in my

personal opinion. 



Another factor is that we do not know what climb speed that was being

used!  If someone was running high power on a super hot day and had the

speed down to Vx, or even Vy, then what the heck, the darn thing is

going to get HOT.   



Consider pushing the nose over, and climbing at a higher speed.

Consider step climbing and reducing the power to cool off.  Another

important tidbit that impacts engine temps during high power climbs is

the timing on the mags.  It isn't always a fuel issue, it can also

easily be a timing issue.  



I am not arguing against changing compensation jetting, but this

aircraft is being flown in Virginia with some of the highest

temperatures for that area in recorded HISTORY!  I mean it!  Today in

North Carolina, we are expecting to set a new temp. record for this date

and time.  If the aircraft is being sold and moved to a different area,

I would strongly suggest not messing with the carb until it gets to it's

new home and this issue is looked at again.  



Just my 2 cents for a reality check.  Not to mention you are only

looking at one cylinder, and you also do not even know if the instrument

you are looking at is accurate! (As Dennis noted)  Step back and look at

this again carefully Steve.  



Mark



--

dsavarese0812(at)bellsout
Guest

Posted: Thu Jun 24, 2010 11:02 am Post subject: Yak 18T

Try moving the temperature probe to the rear plug of #4  cylinder and see what the reading is.  The Yak 52's temperature probes are  under the rear spark plug of #4 cylinder.  Although I have seen them at  times on #2 and #3 cylinders as well.

  

 Dennis

 [quote]   ---

bigglesusa

Joined: 29 Apr 2009
Posts: 57
Location: Franklin VA

Posted: Thu Jun 24, 2010 11:37 am Post subject: Yak 18T

Thanks Mark you are right as usual.  We have 105 F advisory today and is

probably hotter out here in the sticks.  No flying today.  New owner will no

doubt sort it when back in Washington State. Steve



--

_________________
'Le temps mange la vie'

wise(at)txc.net.au
Guest

Posted: Thu Jun 24, 2010 3:02 pm Post subject: Yak 18T

G'Day Dennis.

  

 I sell GT props here in Australia.

 The prop is, without doubt, a far smoother prop and  does offer more performance, in the climb, in the cruise and is a very  noticeable improvement in aerobatics.

  

 But I cannot lay my hands on one of these  spinners.

 I have customers for them and cannot yet  supply.

 I this morning have send GT Propellers an email, in  red, Asking for update on the spinners.

 I shall post the reply.

  

 Cheers,

 Chris.

  

 [quote]   ---

dsavarese0812(at)bellsout
Guest

Posted: Thu Jun 24, 2010 3:06 pm Post subject: Yak 18T

Excellent Chris.  I'm sure there will be many people  interested in your post on the status of the spinners.

 Dennis

 [quote]   ---

Display posts from previous:

	Matronics Email Lists Forum Index -> Yak-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum