Alltrikes

There is an industry stigma that Rotax 2 stroke engines 503/582 are not as reliable as the 4 stroke 912 and they die quickly and for unknown reasons. The truth is that 2 strokes do not die, THEY ARE MURDERED.

Here are some simple tips to help you run your 2 stroke as reliably as possible.

MIX OIL AT THE PROPER RATIO

First and most important – use the manufacturer RECOMMENDED mixing ratio. Most Rotax 2 stroke engine failures are simply from lack of lubrication. I have heard so many stories about how people are so proud to have mixed at 100 to 1 instead of the required 50 to 1 because someone said it was OK. At 100 to 1 the engine runs great with less smoke but with half the engine manufacturer lubrication it will fail. That would be like running the four stroke with half the lubrication. The oil injection system is a great way to provide the proper mixture the engine without having to premix at 50 to 1. It provides the proper mixture at full throttle 50 to 1, and a higher mixing ratio progressively to idle. Overall, oil injection is great because it will produce less carbon deposits in the engine allowing it to go further without decarboning.

USE GOOD OIL

Use a good well know reliable oil. Many engine failures are from some new oil mixture, some magic new oil or someone trying to save money on cheap oil. I recommend three types of oil. The most reliable over history is the Pennzoil - 2-cycle Air-Cooled Engine Oil. This has been tested and is proven to be the best dinosaur oil. This is the preferred oil if you are in a humid area and/or go for longer periods without running your engine. Pennzoil - 2-cycle Air-Cooled Engine Oil produces the least amount of carbon deposits (for dinosaur oil) and keeps oil on internal components with so they do not corrode when sitting in a humid environment  for longer periods without being run.

The new Aero Shell Sport PLUS 2 has been recently developed specifically for Rotax 2 stroke engines and has been tested and provides the same protection as the Penzoil. This is another recommended viable option.

Another option is Amsoil 2 stroke synthetic oil for low humidity environments where you run the engine more and do not let it sit around for long periods. The advantage is that it produces less carbon and burns cleaner. The disadvantage is that the synthetic oil which does not coat the internal components of the engine as well over time allowing internal corrosion which can lead to engine failure.

USE GOOD FUEL

Using fresh fuel from a major manufacturer will help an engine run better and avoid detonation and preignition which will cause extra wear and tear and eventual engine failure. Higher octane fuels are generally more refined and higher quality so pay the extra per gallon for a quality brand high octane fuel. Fuel degrades octane over time so fresh fuel is better. I usually drain my fuel if it is more than 3 weeks and put in fresh fuel.

MANAGE ENGINE TEMPERATURES

Warm the engine up. If you go to takeoff power with a cold engine, it creates extra wear and tear and will fail than or create damage and fail later. Even when the CHT and water temperature reach the proper operating temperature the crank and gearbox may not be properly heated for takeoff power . Besides getting up to operating temperature, I run my two strokes for at least 6 minutes in the summer and 8 minutes in the winter to warm the complete engine before takeoff power. If you do a long descent the engine cools to below operating temperature. During a long descent bring the RPM UP to somewhere mid RPM 400/4500 to warm it up before applying full power. If the engine is cold and you go right to full power, the aluminum piston will heat up, expand and will either scratch the inside of the cylinder which will lead to eventual engine failure. Many times the engine will seize/stop as the piston gets big enough where it cannot move. This is the classic problem where the engine fails, the engine piston and cylinder walls equalize, and then the engine starts and runs fine. This “Cold Seizure”  is the big mystery of why the engine stopped but runs fine now. It runs fine but has been damaged because the inside of the cylinder walls and piston are scratched. Simply managing your engine temperature will avoid this problem. The 582 Blue head does have 2 thermostats to minimize this situation but proper temperature management will avoid this problem.   

NO REBUILDS

Historically, rebuilt engines have a much higher probability of failure than a new factory spec engine. I do not trust a rebuilt engine. A new block (crankcase, pistons, head, electric/mags, oil injection) only cost about $5000 for a 582 so simply replace the block when it is time.  In my opinion, a rebuilt engine is unreliable and worthless. I have only heard bad things about rebuilt engines.  When is it time for a new engine? Rotax recommends and requires for S-LSA a rebuild/new engine at 300 hours. Industry experts say with proper operation as discussed above they can go about twice 600 hours to 800 hours which plenty of 505/582’s go. I replaced my 503 at 750 hours. I premixed Pennzoil at 50 to 1, ran premium fuel, managed the temperature and never had a blip, hesitation or bad moment. At 750 hours, it ran great, compression was good and there was no difference when I put the new engine on.  Two strokes run great unless they are murdered.