Why did Jabiru build its own engine? - report

Flyer magazine engine report

50,100,200 hour checks

Jabiru Engine  2200 - Cold starting

Jabiru Engine 2200  - General info

Propeller - Noise Certificate for UK UL

See Jabiru web site for engine spec.

Cooling ducts.



Contributed by:

Sensenich Wood Propeller Co. Inc. ground adjustable propeller Clive James

Photos show a third ignition system.(Photo1)  (Photo2) These have been in use for some time although I haven't fitted one myself. In the event of an (almost) flat battery the engine can be hand propped, or if the battery still has enough kick to turn the engine over, it will fire. Your PFA may not approve! Also attached is a photo of one of my tyres ruined by 'landing on the grass'

Andy Hollitt

This engine mount compressor is easy to make and very useful

Andy Hollitt

Donut spread out

My lower engine mount rubber donut spread out, making it quite useless. A harder donut won't spread, but doesn't absorb engine vibration too well either, so I turned up some aluminium cups

Andy Hollitt

To prevent cylinder corrosion (rust) if you don't use your Jabi often, or if you hanger in a moist environment, add Castrol TTS 2 stroke oil to your fuel at a ratio of 300 or 400 to 1.

Leakdown Tester

For an article on valves go to www.avweb.com/articles/pelperch/pelp0059.html.

A commercial Leakdown tester is at www.racerpartswholesale.com/long29.htm.

For the DIYers go to http://www.motorcycleproject.com/motorcycle/text/leakdown.html

The restriction is .040" diameter and .25" long. Use 80 psi test pressure.

Andy Hollitt

Oil Bottle

I screwed a brass nipple in to the bottom of the oil bottle then ran silicon tube from it, up the side of the bottle and shoved through a hole at the top of the bottle, so the end reaches back down to the bottom, ie a big loop, but not joined. Now I can easily see the oil level in the bottle by checking the oil level in the silicon tube. To empty the oil, simply pull the tube out the top hole and let the tube hang straight down in to a bucket, too easy!

Andy Hollitt

New GT Prop

I just wanted to say how impressed I am with the GT Propeller which I have on my SP. The propeller is quieter and smoother than anything I've fitted before. Made from Ash laminate it has a thick resin leading edge and rounded tip to limit noise. Fuel consumption looks to be improved by at least 1 litre an hour (measured over 20 hours flying @ 2800). For comparable speed that would equate to 2 litres or so saving.

Clive James

See photos of Carb rubber, only sign on outside was the rubber was allowing the carb to move about, inside was split 3/4 of the way through.

Engine has run 300 hours, (250 flying hours not inclding taxying etc.)

ST.Aviation has them in stock.

Clive James

Jabiru 2200 Modification by Serial Number Reference

Recently, there have been questions raised by Jabiru 2200 owners as to the modification updates that apply to their engines. Also, for those builders shopping for a used engine, it is helpful to know which modifications apply to a particular serial number.

To assist both groups, I have listed below most, but not all, of the key changes, updates and modifications by serial number for reference. The source of this information is the Jabiru Parts Manual dated 12/10/00.

Early Style Engine using:

- 2 bolt valve covers

- Cylinder heads and barrels with flat mating surfaces

- Head gaskets used

- Angled bottom Cast intake: 22A001 – 22A106

Modified Early Style Engine using:

- 2 bolt valve covers

- Cylinder heads and barrels with recessed mating surfaces

- NO head gaskets used

- Angled bottom Cast intake: 22A107 – 22A224

Note: Recessed heads and cylinders of this modified early style engine were also selectively used prior to ser. # 22A107 on the following engines:

- 22A055 – 056

- 22A070 – 074

- 22A078 – 085

- 22A094

- 22A099

- 22A100

Late Style Engine using:

- 4 bolt stamped valve covers (“Gold Top”)

- Cylinder heads and barrels with recessed mating surfaces

- NO head gaskets used: 22A225 – to present

Late style cylinder heads:

- Standard fin heads: 22A225 – 22A644

- Extended fin heads: 22A645 – 22A709

- Offset fin heads: 22A710 – to present

Late style intake manifolds:

- Flat bottom Cast intake: 22A225 – 22A698

- Machined flat bottom (higher flow intake): 22A699 – to present

Connecting Rods:

- Engines using Aluminum Connecting Rods: 22A001 – 22A436

- Engines using Steel Connecting Rods: 22A437 – to present


- Engines using 32 mm Bing Carb: 22A001 – 22A698

- Engines using 40 mm Bing Carb: 22A699 – to present

Rocker Arms:

- Engines using 10 mm wide rocker arms: 22A001 – 22A188

- Engines using 12 mm wide rocker arms: 22A189 – 22A307

- Engines using 15 mm wide rocker arms: 22A308 – 22A658

- Engines using late offset rocker arms: 22A659 – to present


- Engines using standard duty starter motor: 22A001 – 22A659

- Engines using H.D. Bosch starter motor: 22A660 – to present

Crankshaft Gear:

- .250” wide gear: 22A001 – 22A436

- .312” wide gear: 22A437 – to present

Push Rods:

- Aluminum push rods: 22A001 – 22A224

- Steel push rods: 22A225 – to present

Please use the above information at your own risk.

It is for reference ONLY and may be in error.

Kerry Owen

Kerry Owen



Longer oil temperature probe

Engines with a serial number below 146 should have fitted a longer probe, if you have an applicable engine and have not changed the probe contact S T A for replacement. ( UK supplied kits )

Throttle arm movement

There have been a couple of incidents where the throttle has been set up in the wrong direction, and closed was actually fully open. The spring, on the arm pulls the throttle open not closed, therefore pushing forwards is open and pulling against the spring is closed. On BMW motorcycles that use the same carb. the butterfly valve only opens 75 degrees. It has been found on recent installations that there can be some vibration climbing out and reducing the throttle setting eliminates this and sometimes an increase in power is experienced. If vibration is experienced and pulling back on the throttle stops it with no loss of power then you should adjust your set up to give 80 degrees movement.

Cylinder Head Torque Settings

It is very important that new engines have their cylinder head bolts checked and tappets adjusted at around five hours, fifteen hours and twenty five hours. This must be undertaken when the engine is cold. You will require a good quality torque wrench that covers the range required. Kevin at STA once observed someone trying to torque at 15lbs with a 20lb wrench, wound below the twenty mark, no wonder the thread gave way!

Head torque for ALL engines is 24ft/lbs. No longer 18ft/lbs for Engines above serial number 22A/436

Gold top engines require the removal of a plug to gain access to one of the head bolts, this must be done and cannot be ignored. When replacing the plug use Loctite 142 or 143 after degreasing.


Pull the engine through and observe both the exhaust valves immediately followed by the inlet valve cycle, when the inlet valve has stopped moving, rotate the prop a further 180. Both rockers should now be free and can be checked and adjusted. We set out tappets at twelve thou' instead of ten as generally we find a tendency to tighten up, particularly on new engines.

Crankcase vent oil overflow bottle

The overflow bottle supplied with the Jabiru kit plane is fitted to the firewall with a vent pipe extending out the bottom of the cowling. To prevent a vacuum and siphon action occurring, flock a 1/4" aluminium pipe into a hole drilled into the top of the bottle. Make another hole and pipe fitting in the top and connect a tube to the fuel vacuum pump vent to catch any fuel venting.

Carb. float bowl

Connect a pipe to the vent on the float bowl and take it to a 1/4" aluminium tube flocked into a hole in the top of the Carb air intake filter box. This helps equalize the pressure inside the carb float bowl which can be affected by the pressure changes inside the cowl


Oil-cooler diverter sandwich ring

I noticed oil on the cowling close to the front where the upper and lower cowlings are split and tried to locate the reason. It turns out that the O-Ring betwen the engine block and the oil-cooler diverter sandwich ring had some flat spots and was getting hard. Replacing it solved the problem. I got the rubber 'O' Ring in Naples about 20 min away after some looking in some local stores around here. I change my oil every 20 to 25 hours and replace the filter as well at that time. They are cheap and its good practice.

Karl Geng

Oil pickup tube

I received the info from down under about the oil pickup tube. Engines below serial #307 need to be pinned because they could fall off. Apperantly very few have had it happen, but its possible. Also the length of the pickup tube has been lenghtend so that cooler oil from the very bottom of the sump gets picked up. They advised me that there is a new oil pump. Its called a 14mm pump vrs. the 12 mm pump which we have now. I assume thats the depth of the pump blades. Its to give more oil pressure. Also to add two washers to the oil relif valve. If any of this info seems appropriate to any of you, you should contact Jabiru or local rep. and see if your serial #s are effected.

Tex Mantell

Oil drops

At 105 hours now on my Jabiru SK with the 2200A engine I noticed oil drops on the left firewall and some on the left cowling where the upper and lower cowling meet. An exhaustive search finally found the source.

The paper gasket under the fuel pump on the "Right" side was bad. The oil drops were blown to the other side and that is what made finding this very hard.

Anyway bought some gasket paper and with punch and scissors made a gasket. Not a drop of oil seen since. Meanwhile I learned the gasket is available from Subaru car parts departments.

Karl Geng

Cooling ducts.

Something I have done which has made a huge difference to high cylinder head temps is the addition of the deflector in the cooling duct. This modification was recommended to me by the local agent who received the information from Australia. There are two things they advised, placing a deflector at 45 degrees to the horizontal above the two back cylinders and increasing the size of the inlets on the top cowl. I have only done the deflector so far and this has proved to be quite sufficient. The climb temperature has dropped from 200 to 160 degrees, with just over 100 at cruise from the original 160. (I have the wide ducts) Everybody who has done the modification has had similar results. We are all very pleased.

At the time of writing - new jab cooling ducts are the narrow ones with the deflector already fitted (Vic Leggott)

James Bentley

See the advice from the Jabiru Factory on COOLING DUCTS


Opened out air intakes

I have recently opened out the air intakes on my top cowling to match the size of the cooling duct and found a reduction from 140 degrees in the cruise to 105 degrees! I already have the deflector fitted. This will only apply if you have the bigger cooling ducts. see some photos

Vic Leggott


Deflectors fitted to the deeper opening air inlets at front of cowl get more air to the back.

Andy Hollitt

My Jab now has 65Hrs on the clock and is going fine. Fitted steel conrods, solid pushrods and oil cooler before first flight. Have since fitted slotted tappet adjusters (available ex factory)instead of the hex key type which have been known to snap if over tightened, strong backs on lower head bolts (to reduce warping of the head) and revised cooling ducts (ex factory) which lowered the CHT in cruise from 150 C down to 105 C. Oil is now a little too cold in winter at 65 C but rises to 75 C with oil cooler fully blanked off. Summer requires it to be unblanked as temp rises.

Geoff Hennig


There is much confusion about the range of propellors supplied with Jabiru aircraft supplied to the UK with 2200 engine . Both the PFA and the CAA were under the impression that while they all had a diameter of 1524mm (60") there were a number of different pitches around. Indeed I think ST Aviation believed this to be true, because we had planned to get the CAA to noise test my aircraft with as many different props as STA could supply, in the hope that one day of testing would suffice for all Jabiru owners.

To add to the confusion, one of Jabiru's subcontractors in Australia has mis-stamped a number of propellers as having a pitch of 1066mm (42") in error for the correct pitch of 1016mm (40").

Due to Kevin Pearse's absence at Oshkosk, I approached Rodney Stiff, Jabiru's Joint MD in Australia, and have received written clarification which I have copied to Steve Arrowsmith at the CAA Noise Testing Section.

The truth is that there is only one specification of propeller supplied in UK kits for the 2200 engine. These are described as Propeller Type: C000242, have two blades, are of wooden construction, and have a diameter of 1524mm (60") and a pitch of 1016mm (40") REGARDLESS OF WHAT IS STAMPED ON THE PROPELLER beneath the spinner.

The CAA noise tested Cloudbase Aviation's Jabiru UL on Wednesday August 4, and it passed with flying colours at some 3-4 dB below the max acceptable level. The dB scale is a log scale so 3-4 dB is an enormous margin - but then we already knew that noise whas not going to be a problem!

The good news is that the CAA now has all it needs to issue a noise certificate for any Jabiru with a 2200 engine and a C000242 prop without further testing. If you need one (all aircraft to be registered as a microlight do) contact Steve Arrowsmith on 01293 573074 or Fax 01293 573977.

Regards and thanks for a great web site.

David Johnston

When you fit the prop.....

Stand in front of the prop looking back towards the flywheel. Position the flywheel so that the magnets are vertical. Position the prop so that it is located in the prop guides that give it an 11.00 o'clock position. It should now stop in the horizontal.

Vic Leggott
Cold starting           

This is an area where new owners have to get used to their new engine.

1. Make sure that the idle speed is set low at 700rpm

2. The throttle must be fully closed

3. The choke must be fully on.

4. Pull the engine through 6 blades by hand, having switched on the master switch and fuel pump (MAGS OFF!), the throttle and choke set as above.

5. Switch the fuel pump off and only give short 3-4 second burst on the starter.

7. If conditions are severe consider pre heating the engine, you only need to warm the carb.as it is the fuel temperature and atomization that is the problem.

The cowl can be pre heated by blowing warm air into the lower cowling with the cowlings in place, you can use either mains or 12v fan heater, hair drier, or hot air gun. Maplins produce an ideal 12v car heater that can be run from your car or a separate battery.Contact Maplin sales (UK) on 01702 554 000. order code MX98G price 17.99 inc. vat

The alternative would be the installation of the fuel primer that would squirt fuel into the inlet manifold.


Cold Starting

1. Close spark plugs to .018"

2. Install an N24 Yuasa battery it's a 24amp the same as most ride on mowers use. That thing Jabiru use is just a toy at 18 amps

3. Close the magnetron pickups on the flywheel to .010"

Rod Stiff ( Jabiru Aus) sets them at .016 We tried .006 but they touched at revs so be careful, I bought some long feeler guages they're about the size of a hachsaw blade and are available here separately. An 8 &10 &12 are quite handy.

I still set the plugs at .020" and have the magnetrons in a bit at 10 or 12 thou. I HAVE NEVER USED THE CHOKE  ON THE 2200 80 HP

A box containing the N24 battery is very tight and the battery has to be fitted with the box. It is a bit of a nuisance but worth it. I made it out of 1mm stainless steel and it must fit very snug. Yuasa in my opinion are no better than any other regular make the secret is a good one perhaps a new one every year. Jabiru are recommending Odessy Batteries- they are significantly better but not available in NZ and very expensive The result is a bit of  lead in the tail

The engine will not start if it does not really spin fast ---300 RPM

The throttle idle speed must be 800 RPM or lower. If you use throttle in desperation by opening it then you will kill your chances.

A high idle setting on the throttle will severely limit the choke

Ashley Johnston

Carb Icing - some basics

Carb icing CAN develop on the ground, the best test is to fully close the throttle just before lining up, if the rpm is low, erratic or the engine stops you have got ice present, apply carb heat for around twenty seconds and re-test. Apply ten seconds of heat during the power check as a matter of course.

Use carb heat in flight regularly, typically every ten to fifteen minutes for about fifteen seconds.

Always use heat during descent, but select off on short final.

If at any time a slight vibration is felt, use carb heat, if when heat is selected vibration occurs or gets worse this is a sign of ice present.

STA fit an inside/outside temperature gauge from, 'R.S.', Maplins and Tandy with the probe inside the carb heat box. This shows how much heat is being applied and sudden drops will indicate icing conditions present.