Rotax Rebuild Times

[Dyceman]

RE: Rebuild times for 503/582

I've read that both the 503 and the 582 "should" be rebuilt at 300 hrs or 5 years, whichever comes first.

Questions:

1. Is this really true? If the engine is running well - do you rebuild it anyway if it reaches one of the above limits?

2. Besides hobbs time and age, how can you tell that your engine should get rebuilt? Do you check the compression? Are there other indicators that would tell an operator that it should be rebuilt pretty soon? Or you just know its time when it stops working!!

3. Is the age factor very important? If you only had 200 hrs on the engine and it was running well but was 5 years old or more -- should you have it rebuild anyway because of its age?

4. What is the approximate cost to have a 503 and a 582 rebuilt? I know it would depend on a few factors and if any parts had to be replaced -- but a general idea of how much $$ we're talking about here would be helpful. I doubt this is something you could do yourself right?

Thanks again for the info!
Dyceman

[Matthew Roung]

2. Besides hobbs time and age, how can you tell that your engine should get rebuilt? Do you check the compression? Are there other indicators that would tell an operator that it should be rebuilt pretty soon? Or you just know its time when it stops working!!

~The recommended TBO is just a guidline. There are lots of good indicators as to rebuild or not. A compression test is good, gives an indication of your topend's health. Engine rpms dropping off could indicate your engine needs attention. For the cost of a few gaskets, it is an easy job to remove the heads and/or cylinders to physically check the top end out. Just because your engine reaches the listed TBO does not mean a rebuild is neccesary. It is a good time to open up the engine and check everything out, though. Could be nothing needs replacing (except gaskets and maybe seals). Piston rings are not too expensive, so I prob would at least replace those.

3. Is the age factor very important? If you only had 200 hrs on the engine and it was running well but was 5 years old or more -- should you have it rebuild anyway because of its age?

~I think this is mainly to do with the seals. A 2-stroke is very succeptable to anything that changes the mixture. A leaking seal could cause a seizure if overlooked because of the lean condition it creates. If an engine sits for a while, the seals could harden and not seal well.

4. What is the approximate cost to have a 503 and a 582 rebuilt? I know it would depend on a few factors and if any parts had to be replaced -- but a general idea of how much $$ we're talking about here would be helpful. I doubt this is something you could do yourself right?

~A few years ago I rebuilt my 582. New pistons, rings, cyl hone, bearings, seals, gaskets, etc. I think it was around $600. My crank was fine so aside from seals and bearings, the bottom end was left alone. These engines are very simple. If you take your time, keep things clean, and follow a manual, no reason anybody couldn't succesfully rebuild their own engine. I think much of the reliability of these engines is dependant on the owner. Knowing your engine inside and out goes along way to keeping it running well.
-Matt

[Trev Page]

Agreed, 2-strokes are very easy to work on since they are mechanically simple.

I would never undertake a 912 rebuild though, too many parts!!

[Dyceman]

Excellent info guys . . . thanks!

Dyceman

[macandrews]

Hey guys,
I have flown behind Rotax 2 strokers for 1000 plus hours with only 2 engine outs that I can remember and I know that that is something you don't forget very quickly. A lot of this has been hauling students around too!!!!!
When it come to reliability you the pilot should be aware of the noises and little quirks of the Rotax 2 stroke. I know that if you have the necessary guages esp coolant temp and the main one for me is Exhaust Gas Temperature on your dashboard to monitor the little beast that you should not have any trouble that you can't fix.
One thing I haven't seen much mention of is the pitch of your prop. I know that on any given day the air is pretty more or less dense and you as the pilot in this case using experience as a guide, can change the pitch to suit the occasion like winter on skiis a prop change on a 582 could need a more positive bite as much as 2 or 3 degrees to keep temps in the "good" green and in summer the reverse is true. I have on numerous occasions seen this mid summer on floats here in Newfoundland.
So as Trev said in a previous reply rebuild times come when you need it and your Rotax will tell you if you just take some time out to look at it. Cylinder heads are very easy to take off as well as compression checks every now and then. I have found that watching this little engine in this way can give you years of enjoyable flying pleasure. Safe flying!!!