Engine Repair – Archive

Andy hands with micrometer
Heavenbound Aviation is an authorized “independent Rotax Repair Centre” for Leading Edge Airfoils.  Andy is an FAA certified A&P mechanic, an ASE Certified Master Technician, as well as being Rotax and factory trained and certified in their two stroke and four stroke lines of engines. Heavenbound Aviation can do all types of repairs, inspections, and overhauls of all Rotax two and four stroke engines. We sell and install new Rotax engines as well.  Heavenbound aviation is also trained and approved to do all types of repairs, inspections, and overhauls on Hirth engines including EFI systems.  The flat rate labor charge for a rebuild of any air-cooled two stroke Rotax is $550, and for liquid cooled models, $650.  (some exceptions apply for unusual damage or added components requiring significant extra labor, but that is unusual.)  Gearbox removal inspection and reassembly is an additional $50. If the gearbox requires additional repairs, that is extra.  If the engine comes here with accesories attached, such as engine mounts, belt red rives, electric start, etc. there may be additional labor time to remove and reinstall and/or service them.  The standard labor rate is $65 hr.

Fly-in repair service is available, but availability is limited due to hangar space and must be scheduled ahead of time.  Also, please note that our runway is 900 feet long east to west and is surrounded by crop fields.  It has wide open approaches on both ends.  Please make sure your aircraft and skills are capable of safely operating from that runway length.  All are welcome to fly in, at your own risk. For on board maintenance, repairs and inspections as well as engine removal and reinstallation, the shop labor rate of $65 hr. will apply.

Andy with dial bore guage

Our focus is not on high performance engines, but on high reliability engines.  We do not build racing engines, or experiment with aircraft engines. There are plenty of other shops that specialize in that. We follow Rotax specifications and procedures except in a few instances where we have found ways to correct specific problems common to an engine, or have found truly superior parts available.  All engines are reassembled using OEM Rotax aircraft grade parts unless the owner specifically requests other parts, or in the case of older engines, if those parts are no longer available.  Also, there are now some parts available that are superior in quality to Rotax parts and can be substituted at the owners request.  These include but are not limited to; viton crank seals, viton head gaskets for liquid cooled engines, and JBM rubber products such as carb boots, ignition and cable boots, etc…  Also, older 532 and 582 greyhead engines can be upgraded to the ceramic waterpump seal that is used in the blue head 582.  This requires machine work to be done to the crankcase, and can only be done during an overhaul.  The cost for the ceramic water pump seal update is $125. In some cases engines may be reassembled with parts that are out of spec, BUT ONLY if the owner of the engine is aware of the situation and makes the decision to do that, and the warranty may not apply if the parts that do not meet Rotax specs cause a failure. For example, Rotax recommends replacing the crankshaft at 300 hrs. Since a crankshaft for a 582 now costs $1500, and crankshaft failure is unusual, many people choose to run them longer. (and I would too!)  Please be advised that if you choose to fly a Rotax engine that is out of spec, you do so at your own risk. (of course if the engine is in spec, you still fly it at your own risk!)  In any case, once an engine is taken apart and all parts inspected and measured, the owner will be contacted with an explanation of what needs done, and pricing.  Prior to reassembly, most parts will be bead blasted with plastic media and thoroughly cleaned with solvent. Sheet metal parts may be glass bead blasted and painted at the owners request for a small additional fee.

Rebuilt 503 image

OIL:  Unless otherwise requested all engines will be assembled with Aeroshell Sport 2 aviation oil. (non synthetic) If you would prefer the engine to be assembled with a different oil, please send a pint of that oil with the engine. It is recommended to run the engine only on the oil it is assembled with.  Aeroshell is a mineral based oil and generally speaking any mineral oil should be compatible with it. However, if you intend to run on synthetic oil, compatibility with mineral oils may be an issue, and mixing them should be avoided.  Often we are asked what oil should be used in a Rotax.  In our experience we have seen high time engines come through the shop for teardown using several different oils.  Of those I can honestly say that there are three that I feel comfortable recommending.  Aeroshell/Penzoil, BlueMax, and Amzoil.  I have also been impressed with Valvoline and Castrol so far.  One oil that I have seen repeated serious issues with is Yahmalube.  I do not recommend running Yahmalube in any aviation engine.  One caution I will say with Amzoil or other synthetics is that they may not protect against corrosion as well as mineral based oils. When the engine is in use regularly this is of little concern, but if your engine will be inactive for any length of time, it should be fogged and sealed up to prevent internal damage and possible failure due to corrosion on the crankshaft and cylinders.


  WARRANTY:  All engines that receive an overhaul at Heavenbound Aviation come with a 1 year warranty that covers all workmanship and parts that were replaced.  Please let me explain this a bit.  If  I completed a 300 hour overhaul on your engine including a new crankshaft and that crankshaft fails during the warranty period, that is warranty and will be fully covered including other damage done to the engine from that failure.  However, if you chose to reuse the crankshaft and it fails, that is not covered under warranty.  If, for example, you had an overhaul performed here and later your stator or ignition coil fails, that would not be covered under warranty, that is a normal random failure. However if I replaced that part during a repair or overhaul within the warranty period, it would be covered.  Having said all of that, please be assured that I highly value my reputation and will go to great lenths to please my customers.  It is quite possible that  I will fully or at least partially cover things that really would not have been covered by the warranty to make sure that I have happy customers.  I have had very few warranty issues in the last 10 years.  If there is ever a problem I want to make sure that if at all possible my customers are pleased with how it is handled.  As far as I know I do not have any customers who were not completely pleased with my work, and should you ever meet one, please tell them to contact me to see if we can make it right.  Please note that I cannot cover shipping in my warranty.  I receive engine work from all over the world, and shipping costs can be quite significant.

SHIPPING: If you plan to ship your engine, please do not use UPS. They have a habit of destroying engines and not paying for them even when insured.   No matter if it falls out of a truck on the freeway at 60 mph and gets runover by the next ten trucks, they will claim it was not packaged properly.  I always ship engines in a wood crate.  FedEx has done well for me so far and I exclusively ship engines with them.  If you prefer you can email me the weight and dimensions of your crated engine and accessories and I can arrange for FedEx to pick it up at your location.

Crating:  My preferred way to ship an engine is to build a wood crate.  I start with 2×2 lumber and build a frame 18″x 18″x 24″.  I then use a piece of heavy duty wood such as 3/4 plywood, or 5/4 decking as an engine mount plate that is bolted to the engine, then securely screwed to the 2×2 frame.  After that I sheet all sides of it with 7/16″ OSB or other suitable, sturdy sheet wood.  All other pieces and parts should fit neatly in the space around the engine.  A Rotax engine with GPL starter and gearbox will fit, but if it has a Rotax starter and gearbox, the starter will need to be removed.  A Hirth air cooled engine may need a slightly larger crate if including other components.  18 x 24 x 24 should suffice.  Also, I include rope handles on the ends to have mercy on the poor FedEx driver.  And never put runners on the bottom.  If it can be moved with a fork truck, it will be, further increasing the odds of damage.  UPS ran a fork through 7/16 plywood and broke a casting on a gearbox once.  And of course it was my fault for not putting dense foam around it. Like that would stop a fork truck…  Just one of the many reasons I ship with FedEx.  If you have any questions, please contact us!

Hirth engine cratedGood Crate

poor crating jobBad Crate

Josie shipping managerGood Shipping Manager!


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