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About skypics

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    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 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.
    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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  2. skypics added a post in a topic Jab 2200 Gen 4 installation   

    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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  3. 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.
    John M
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  4. 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
  5. 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
  6. 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
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  7. 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.
    • 1 reply
  8. 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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  9. skypics added a topic in Avidfoxflyers General Hangar   

    Tests of new Gen 4 2200
    It's been just 21 hours so far after installing my new Jabiru Gen 4 2200.
    I have flown behind 2200s for over 3,000 hours and in that time I have had a sucked exhaust valve, a displaced valve seat and relined my valve guides 3 times. Of course, this also happens to "real" aircraft engines. That said, I have always thought that while the bottom section of this engine was very robust, the top section had many design flaws caused by inadequate rocker box lubrication. 
    This causes early valve guide wear which causes sloppy valve positioning which can result in valve head separation.
    In contrast to the earlier generations, the Gen 4 appears to have addressed these flaws with;
    A) Larger fins
    B) Head and jugs are now cast aluminum instead of CNC. This allows tighter tolerances since the piston and cylinder are of the same material.
    C) The rocker boxes are lubricated up through the pushrods where the oil moves into the rockers and to the rocker bushings. 
    D) The engine starts every morning in two blades without using the choke. When warm the engine starts instantly. I believe it may be hand propped. I will try this soon.
    E) The engine can idle smoothly at a mere 600 RPM.
    F) After tweaking the air duct to fit under my Avid MK 4 cowl, all CHTs and EGTs are well within specs as recently tested on a long climb out from 533 MSL to 9,000 MSL at full power.
    G) After 21 hours the oil still looks clean and still is at the dip stick full mark.
    H) There is only a tiny bit of water/oil collection in the breather bottle.
    I am swinging a Whirlwind 66"two-blade prop.
    So far I am well pleased with this engine.
    I did have to buy a new engine mount since the new engine moved the top two engine mounts 15 mm to clear the larger fins.
    The new mount cost $895. I sold my old MK 4 mount for $300.
    Sold my old 2200 for $2K.
    The new engine was $15K plus shipping.
    John M
    • 1 reply
  10. skypics added a post in a topic Avid Model C or Mark IV   

    Somewhere in my photo files I have photos comparing the installation of a 912 vs Jabiru 2200 on an Avid MK 4.
    The 912 is really packed in there, whereas the 2200 has plenty of room.
    The biggest problem is finding a place to put the big oil can, extra cooler for water and many hoses.
    I'll see if I can find the photos.
    LATER: Couldn't find the photo.
    The advantage of the 912 is that a much longer prop can be used and if the engine is 100 HP it should climb very well. If it is the 80 HP there wouldn't be much difference from the Jabiru.
    John M
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  11. skypics added a post in a topic Jab 2200 Gen 4 installation   

    Everything is still working well on the new Jab 2200 Gen 4 engine.
    I changed from straight mineral oil at 17 hours. I was surprised to see the oil still looks clean. I filled to full with Phillips 20-50 XC oil.
    I haven't detected any oil usage in 17 hours. 
    Was having heating issues with number 2 until I corrected the placement of the air dam. Now #1 is a bit higher than #2 but only runs 310 in cruise in 85 F OAT.
    Pilots on my field say the engine sounds great on take off. I use a 66" Whirlwind 2-blade prop with the scimitar-shaped blades which is supposed to be quieter.
    The 2200 is a good match for my Avid MK4. 
    So good.
    John M
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  12. skypics added a post in a topic Jab 2200 Gen 4 installation   

    I now have 18 hours on the new Jab 2200 Gen 4.
    I am pleased to report that this engine has been redesigned to correct the deficiencies in the top end lubrication.
    All CHTs read 290 F +/- 30 F in cruise. EGTs are 1200-1250 F.
    This engine is smooth and is putting out more power than the Gen 2 I had. 
    Since I repositioned the air dams in front of the front cylinders so that the dams lay against the fins, the temps are all good. Such a simple fix.
    Have never seen the necessity to add water cooling to add weight and complexity to a simple engine. My Rotax 912 friends have had to deal with radiator issues and water leakage.
    Jabiru says to run mineral oil for the 1st 25 hours, but I have read other break-in articles that recommend Phillips 20-50 oil during break-in. I will be changing the oil when I return from my annual Idaho backcountry trip.
    This engine seems to use no oil. I have been running the oil level at the top mark of the dip stick and it doesn't blow out any oil into the air/oil separator. 
    I will try to do a hand prop soon. I think I can hand start it which would be a benefit if, leaving the master on while in the backcountry strips. Nice to have that option.
    I am still amazed at how slow it can idle. I've had it down to 600 RPM.
    Jabiru used to claim 85 HP on the earlier engines, but now that claim 80 HP which makes more sense the 3300 with 2 more cylinders come in at 120 HP. 
    Fly safely.
    John M
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  13. skypics added a post in a topic Jab 2200 Gen 4 installation   

    After speaking with Nick Otterback of Jabiru Tennessee I found that I had not installed the #2 air dam correctly. 
    It should be flat against the cylinder or else the air flow can dive down under the cylinder instead of over the top.
    After reconfiguring the dam the temp on #2 CHT is now the 2nd lowest running around 300 F in cruise.
    I had to do a LOT of modification on the Air duct to fit under my cowl. Looks like crap now after the modification, but I'll clean it up and apply some paint and it will look better.
    As long it is cooling all cylinders it's not that important.
    Engine runs strong and so smooth.
    It starts instantly at 1st run up in the morning without using the choke.
    I am starting to suspect this engine could be hand propped if necessary.
    It seems to use very little oil.
    I changed from the mineral break-in oil at 7 hours but was told by Jabiru that I should run the break-in oil for 25 hours. So I drained the 20-50 and reinstalled the mineral oil.
    This engine should take me to the end of my flying days.
    John M
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  14. skypics added a post in a topic Jab 2200 Gen 4 installation   

    And the frustration goes on...
    Try as I might, I can't get the #2 CHTs to fall in line with the rest. It runs 350 F in cruise at 2800 RPM while the rest run 300 +/- 5 degrees. The EGT is 100 higher than the next highest also. It reads 1280 F which is within spec. This is with OATs at 70 F.
    I have eliminated the thermocouple and the Grand Rapids EFIS as the issue and have cut the air dam in front of #2 down as low as I can with no resolution to the problem.
    I have asked Nick at Jab Tennessee for a resolution and am awaiting his response.
    Any ideas from this group are appreciated.
    John M
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  15. skypics added a post in a topic Jab 2200 Gen 4 installation   

    I had to add more pitch in the 2 blade Whirlwind prop due to extra power. This boosted my cruise about 5 MPH, but I still have a great climb.
    Number 2 CHT is 50 F higher than the rest which are around 300F in cruise. Number 2 would get up to around 350 F. 
    I had to cut the air dam in front of the cylinder to half the height and that corrected that issue.
    I have flown 6 hours so far and other than a small leak, due to the oil filter no tight enough, the engine uses no oil as compared to the older Gen 2 engine. There is only a tiny amount of oil and water at the bottom of my air/oil recovery bottle.
    As you all know, it was impossible to start these engines by propping, but since this engine starts quickly, even without using the choke, I suspect it might be possible to hand prop a start. I just touch the starter button and it starts instantly and can tick over at a low 700 RPM.
    As mentioned before, I had to cut down the top of the air ducts to fit under my cowl.  I actually prefer the older air ducts where the plug wires are on the outside. I believe it is not a good idea to have the plug wires laying inside the air duct to be subjected to all that heat and disturbing the air flow.
    On my older Gen 2, I measured CHTs with a thermocouple junction down inside the head in the hole between the plugs and sealed it with RTV. This engine has those holes threaded and I had to crimp small lugs on the thermocouple and screw them to the head.
    More to come....
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