skypics

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About skypics

  • Rank
    Advanced Member
  • Birthday 08/08/1937

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  • Gender Not Telling
  • Interests Guitar, Piano, Ukulele, Harmonica, my two Maltese dogs, Flying backcountry strips in my Avid MK4

skypics's Activity

  1. skypics added a post in a topic Trailing edge material?   

    I use he trailing edge material as fairings on my Jury struts. Works great!
    John M
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  2. skypics added a post in a topic trim lever   

    After thousands of ours in Avid B and MK4 I finally install electric trim.
    Bought a linear actuator from Amazon and it worked well but too fast, so I bought a motor controller where I can control the width of a square wave to slow the actuator.
    Before, I could always trim in cruise with a little flaperon but on landing with full flaps a higher stick force was needed.  Works great. 
    On my model B I just had a spring from the seat carry through to the lower part of the stick. Then on final I would just slide one end of the spring up the stick.
    John M
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  3. skypics added a topic in Avidfoxflyers General Hangar   

    Using ethanol laced mogas in a MK4
    I have an avid MK4 heavy hauler with the STOL wings and two 14 gallon fuel tanks.
    When I 1st had the model B I could burn mogas with MTBE until it was outlawed. I soon found that the ethanol laced tanks can't handle the ethanol because it softens the resin in the poly ester tanks. At some point I know that Kitfox changed to polyvinyl tanks and was wondering if Avid ever changed and if so...when. My avid was built in 1996.
    A friend, Joey says he has been using California mogas for years in his MK4 with no issues. So, this has me hopeful that maybe my tanks will handle mogas.
    I run a Jabiru 2200 85 HP engine which can except mogas at 91 AKI. 
    As a test I have drained the avgas from one tank and put in two gallons of 91 mogas. I will fly on the avgas in the other tank, and I will drain a little out of the mogas tank each time to see if the mogas starts to turn yellow...a sure sign that the resin is softening.
    Let me know if anyone here is using mogas.
    Two airports near me in SoCal have banned the sale of 100LL and the public is becoming more concerned with the lead we are using even though aviation gas accounts for less than 1% of the motor fuel used in the US. That coupled with the fact that the only supplier of lead tetra ethyl is one producer in England. If that plant goes belly up GA is SOOL.
    John M
    • 0 replies
    • 488 views
  4. skypics added a topic in Avidfoxflyers General Hangar   

    Ethanol safe fuel tanks for Avid Aircraft
    Is there a drop in replacement tank for the Avids that is ethanol proof?
     
    John M
    • 0 replies
    • 450 views
  5. skypics added a post in a topic Picture of your pedals   

    I have larger Aero Classic 21" tires. Larger diameter tires need better braking due to the added leverage.
     
    Although you can have too much brake authority that will end you up on the nose.
    The biggest fault I find with the Avid breaking is that there's not enough room from the top of the break pedal to the firewall cross bar. Your toe can get hung up as you brake.
     
    John M mo
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  6. skypics added a topic in Avid Model IV   

    Love the MK4
    HI;
    Haven't been on this forum in a looong while. Just want to catch up.
    I have had two Avids. A model B which I destroyed on an difficult High Sierra strip. Bought a MK4 with a Rotax 582 2 weeks later. It has a bit more cabin room.
    I saved the Gen 3 Jabiru 2200 from the crash and installed it on the MK4. The prop, mount, spinner and engine were purchased by a man who drove down from Montana to SoCal to pick it up.
    I have over 6,000 hours in Avids and have been completely satisfied with this aircraft which makes me wonder why a business could NOT succeed in the sales of this kit.
    I have been through 4 Jabiru engines. I have had 4 engine failures in that time. Two were exhaust valve failures, another threw a rod 30 seconds after i fired it up. It had been repaired by a dealer near Fresno. He did replace that engine with a newer one. Finally, my new Gen 4 fragmented at 170 hours and was replaced after 3 months by Jabiru Australia.  
    The replacement engine exhibited a very high EGT  on #2 which turned out to be a manufacturing flaw where the induction tube goes into the cylinder. The land that the o ring rests on was much narrower at the 7 o clock position. This caused distortion of the O ring. The O ring is BUNA-N which is only good to 225 F do I replaced it with a Viton O ring that can handle over 400 F. 
    Jabiru would not replace the jug so I had to install a thin shim washer on the o ring land to provide a secure placement. The EGT is now much lower, but still higher than the rest.
    I run a Whirlwind 66" 2 blade set to give 2880 on climb out from my 533 MSL field. My climb rate solo with 12 gallons fuel is 1200 FPM. With 28 gallons climb is 900 FPM.
    I recently flew to Big Bear airport (6750 MSL) and filled it up to the top with 28 gallons. DA was 8900 at take off and I could still climb at 500 FPM only turning 2750 RPM. I leaned out on climb out and got an extra 30 RPM and a climb of 600 FPM. What a fabulous bird!
    I do not prefer the Rotax 912 due to the extra complication of gear boxes, spraug clutches and water supply parts. It is heavier and replacement part are way over priced. I can only imaging how my climb rate would improve with 100 HP, but am not willing to change since this engine has gotten me in and out of many Idaho backcountry strips.
    I don't expect to be flying much longer as I have just hit the 84 mark on life's journey so I'm hoping this engine will last till I hang up my headset for good.
    Fly safe...stay healthy.
    John M
     
    • 0 replies
    • 517 views
  7. skypics added a topic in Avidfoxflyers General Hangar   

    Ethanol Proof Fuel Tanks
    Does anyone here know when and if Avid started using a different resin for the glass tanks.
    I wanted to use 91 AKI in my Avid MK4 for all my short (1.5 hour or less trips) so I installed a marine outboard 6 gallon tank on my passenger seat .
    I can easily switch from the seat tank to the wing tanks.
    Borescope photos are showing that the lead accumulation is flaking off of the top of the piston so it is doing what I want.
    Then I remembered that Avid started using a different fuel tank fiberglass formula, but don't know what serial number. 
    Anyone know when they changed over?
    As I recall the new tanks looked white inside and the old were tan.
    Still enjoying flying my Jabiru powered Avid after over 5,000 hours.
    John M
     
    • 8 replies
    • 1,298 views
  8. skypics added a post in a topic Picture of your pedals   

    John M here.
    I fly an Avid MK4 with 21 inch tires. When I went to these from my 600 x 6 tires my marginal braking was reduced further.
    So I sent off to MATCO and got the mount for using double pucks. 
    The braking as much better, but still not so much that panic braking would cause a nose over.
    As a long time tail dragger pilot, I have learned not to use brakes at all unless absolutely necessary.
    I fly back country strips a lot and do not land on a strip that would necessitate hard braking.  It's too easy to over brake in a panic an nose over.
    A friend with a Kitfox 7 installed 29 inch tundra tires on his Fox. His tail is so heavy I can budge it off the ground. He installed good breaks due to the larger tires and yet while slowing down from a landing with the tail up he braked too hard and put it on the nose. 
    This destroyed the Whirlwind prop, spinner, front of the cowl and the oil cooler.
    I had an instance where after landing I did hard braking to make it off at the 1st exit. I let off the brakes and was instantly pull off the runway to the right; went up on the nose and left wing tip.
    Investigation found that one of the pucks on the right side locked up.
    Had to repair the left wing tip, flaperon hangar and buy a new Whirlwind prop.new prop.
    SUMMARY: The breaks have to be good enough to slow you down, but not enough to easily flip you over in a panic stop.
    PS: I had thoght this forum had been deactivated.
    Installed my 3rd Jabiru engine in August of last year. It is the Gen 4 2200. Jabiru has made many needed improvements to the top end which I like. 100 hours so far with only minor issues, both dealing with the starter Bendix. Much odf the new engines are now cast instead of CNC from a billet. This included the Bendix cover which cracked. It was replaced on warranty with one cut from billet. Then recently the Bendix itself would not engage the starter consistently. This was also replaced on warranty.
     
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  9. skypics added a post in a topic Jab 2200 Gen 4 installation   

    Joey:
     
    Good to see you guys at Dead Cow.
    It was a great experience, but we won't do that again.
    I'm looking forward to next year's Idaho trip and johnson Creek with showers, WiFi, pre-cut firewood, beautiful scenery and great fly out spots for breakfast.
    John M
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  10. skypics added a post in a topic Jab 2200 Gen 4 installation   

    I now have 60 hours on the Gen 4 engine.
    After getting the CHTs all looking good with 300 F on the front two and 285 on the back two in cruise.
    Number two EGT is the highest in cruise and the lowest in climb.  I returned the carb tilt back to level and tried tilting the 11 x 5 x 3 filter a bit to one side and that helped the airflow turbulence so that #2 is much closer to the rest in cruise. when I lean the engine in cruse these EGTS are pretty close to each other.
    I don't normally get too concerned with EGTs as long as CHTs are good.
    I will be taking the engine on its first long cross country this week as I fly to the High Sierra fly in at Dead Cow dry lake north of Reno. This flight will take me over the Sierras west to eat at Lake Tahoe. So I am putting my trust in this engine to keep me out of the rocks.
    It's due for the 30-hour oil change, but I will wait till I return since the plane will be exposed to lots of playa dust from the stol drag contests.
    Later...
    John M
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  11. skypics added a topic in Rotax and other engines   

    Gen 4 Jabiru 2200
    This new engine has improved and resolved all of the earlier issues with the top end of the engine.
    1) Smooth idle down to 600 RPM
    2) No added oil between il changes
    3) Larger cooling fins keep CHTs low
    4) Starts instantly without using the choke.
    5)  Oil stays cleaner longer.
    Finally: Why does clicking on some subjects on this forum take me to a pharmacy advertisement?
    John M
    • 2 replies
    • 1,270 views
  12. skypics added a topic in Rotax and other engines   

    Stuck lifter
     
    I think I have posted about this before, but it needs repeating.
     
    I have pulled the heads on my Jabiru 2200 several times and each time I have had this problem.
     
    The hydraulic lifters on the pulled head do not relax after reinstalling the head.
     
    This causes the valves, sometime only one, but many times both to be partially opened.
     
    You will be able to see this by comparing the position of the valves on the head you didn't work on. They will not be as far out and near the edge of the rocker box edge as the untouched head. 
     
    So when you turn the prop by hand you will find one cylinder with no compression. If the intake valve is held open too, you may see one of the other cylinders with no compression because of lack of vacuum.
     
    If this happens you have a couple choices:
     
    A) remove the head again and pull the lifters and soak them to get all the oil out. You should be able to compress them when they are clean.
     
    B) Start the engine and let it run roughly until the oil temperature builds. This can take 5-10 minutes. You should see the EGT start to build on the soft cylinder and then after the oil is heat soaked the hyd lifters will relax and the engine will smooth out.
     
    Flew it for an hour for check out. All is well now.
     
    John M
    • 0 replies
    • 594 views
  13. skypics added a topic in For Sale and wanted, you got it, I want it   

    Zenith 750
    A friend is dealing with lung cancer and is selling his Zenith 750 powered with 912 ULS. 
    Engine and airframe have 259 hours.
    Sharp looking paint scheme.
    Larger tires for the backcountry strips.
    He is asking $69K
    John M
    • 0 replies
    • 536 views
  14. skypics added a topic in For Sale and wanted, you got it, I want it   

    2200 head
    This head will fit the #1 and #3 position according to the oil feed lines to the rocker box.
    This is the newer head with 21 smaller fins.
    Contact me for a photo.
    John 
    • 1 reply
    • 624 views
  15. skypics added a post in a topic Avid Model C or Mark IV   

    I had a model B and then a MK4 that I bought with a Rotax two-stroke.
    I removed the Jab mount from the B model and installed a Jab 2200 in the MK 4 on the same mount.
    Then I bought a Gen 4 2200 and sold my mount. The mount would not work on a Gen 4 since the top two mounts had to be raised 15 mm to clear the larger fins.
    John M
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