Microlighters

Hey oaks,

I’m fairly new in the game and I’m looking at a aquilla 503 and I need advice. Is the 503 a bullet proof engine like a few people have told me and what is the average life span of such a engine. I have heard guys tell me these motors can do almost 980 hours before the crank needs replacing, is this true? Are there any special things I need to look at? As a cost factor to gain experience and build hours I think it would be a good thing to start off with a 503? Please post me and let me know.

Thanks.

The 503 is as reliable as you make it. Use a good oil, keep fuel and filters clean and replace plugs and its an aweome engine. I have done thousdands of hours on a 503 and each engine out i have had was Pilot related ie dirty fuel etc. It is a great engine and you cannot go wrong with one. I have run a 503 to 1000 hours without toughing the crank and it did it fine. I do not recomend it though so keep maintaining it and it will maintain you. Hope this helps. jamie

Hi ZU-no plane yet

I trust my 800 hour 503 to do the job I ask of it. The motor is about as simple as it gets mechanically, and that means less to go wrong. Many have flown to well over 1000 hours without a problem.

However, you have to understand that reliability is not just a factor of the make or type of the engine. Many factors affect how reliable an engine will be. Among the major ones on the 503 are:

1)How often the engine is used - more often is better, because a 2 stroke engine is lubricated by the oil mixed into the fuel, and a regular dose of oil reduces corrosion in critical components like the crank bearings. Also, fuel degradation (from standing) can cause detonation engine damage.

2)Prop balance, and the type of gearbox fitted. - The old B-boxes are less forgiving with prop weight and pitch imbalance, that can lead to more stress on the crank and premature failure. The C and E boxes have a rubber 'donut' drive coupling, which transmits less of the prop forces to the crank. This is also more forgiving on the crank in the event of a prop strike.

3)Maintenance and inspection (Perhaps I should have put this first). Not cleaning air filters or checking them for damage, not changing plugs at recommended intervals, not checking and tightening the cooling fan v-belt, not setting up and maintaining your carbs correctly, not checking fuel for dirt or water, not decoking the engine at the prescibed intervals and so on - all can lead to major engine wear or damage, which is not obvious from an external inspection.

When buying second hand, it is very difficult to determine whether the previous owner(s) have been consciencious in their upkeep of the motor or whether the aircraft has stood unused for long periods. Hopefully the log-book will be an honest reflection of the engines life. But you can get a feeling for what kind of treatment the engine has received by carefully checking (or having someone else who you trust check) the rest of the airframe. Owners who care about the airframe will in all probability also care for the engine.

I, for one, appreciate the skill and wisdom of the AP to whom we entrust the repair and maintenance of our aircraft, but it is me who will be flying the thing. So I believe I have a duty to myself, to those that care for me, and to aviation in general to know as much as I can about the aircraft, and especially the engine.

One other consideration with the 503 is where you will be flying with it. Here near the coast they are plenty powerful enough, but if your airfield is anywhere above 4000 ft, consider a 582, because 2-up on a hot day, a 503 becomes marginal.

Hope this helps. I am sure that there are many others out there who can help as well

Christian

Well put Christian. That little motor just amazes me with Anton and myself on board
Regards
Bryan
ZU BFR

There is one used everyday in a school at Microlight adventures - 1800 hours and still running sweetly.

Hi

Thank you for all the response and I’m sure it will help me allot. Yes we are unfortunately at 4300ft but considering my weight and my better half is 133kg total I’m sure we should be ok. I just don’t see myself as a beginner to start off with a R80 – R90 K plane? I was recommended by my dad’s brother’s father in law who has been flying 13 going for 14 years that for hour building and experience the 503 would be a better bet, and then invest into a 582. But hey I’m open for help that is why I’m on this site.

ZU – No Plane Yet

Nothing wrong with the 503. Look at my avatar, my bones are quite far below the surface of my skin and my old single ignition 503 took me over the top of Sani Pass without a problem.


Cheers,

Hi ZU-no plane yet

You should not have a problem with that combined weight at that field elevation, especially as you will first be flying mostly solo. Just be aware of the HOT, HIGH and HUMID days. Use the whole runway, and be disciplined about marking and obeying your critical point for being airborne.

Now, go and buy an aircraft and get flying!