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ROTAX 503ul DUCATI

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Tuneturkey

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Dec 29, 2018
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69
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10113, Hyde Park Ct., Baton Rouge, LA 70816
Can some one tell me how to tell the year of Manufacture from the serial NO. on the engine. I have an engine that has never been run, plastic plugs still in place, with no identifying sales information.
Have no idea what shelf life is!
Thanks,
Johnc
 

MadProfessor8138

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Nov 3, 2015
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Ekron,Kentucky
You are going to find that information hard to come by.....been there and done that.
Rotax wasn't too keen on letting their "in house" information flow to the outside world.
The best you are probably going to do is find a general time frame of when that engine was produced..what series..basically from what year to what year for that production run....not an exact manufacture date.

Rotax has a schedule for lifespan of gaskets,seals and etc......even if they've never been used.
I think the longest time Rotax has on any of its seals is around 3-5 years....I could be wrong though.

The only way to be sure is to tear it down and replace all the appropriate stuff so you know the time from when it was overhauled.

Kevin
 

Tuneturkey

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Dec 29, 2018
Messages
69
Location
10113, Hyde Park Ct., Baton Rouge, LA 70816
Kevin, thanks for the info. I did find out that the engine was built in 1992. 17 years ago!! wow!!
Looking at the engine, it looks like a normal new engine, but who knows what lurks inside.
question for you though. The rubber caps on the plug wire connections to the coils have split, and I have replacements. However, the wire ends seem to be permanently attached. how does one remove the plug wire so the new cap can be slipped on the wire? I was told that the wire end is threaded, and if twisted counter clockwise it un-screws. Tried that and could not get the wire to rotate without some damage to the outside of the cable.
Can I just use some clear acrylic sealant in the cracks and close up with a tie-wrap?
Johnc
 

MadProfessor8138

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Nov 3, 2015
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Location
Ekron,Kentucky
Now you're asking a question that I do and don't have an answer for.....let me explain.
Rotax wires are "suppose" to be replaceable by simply twisting them counter-clockwise from terminal on the coil or plug cap.
Now remember,I said " supposedly".
Over the years I have ran across "a few" assemblies that will not come apart,no matter what you do.....they were manufactured as one unit.
And by this, I mean that the factory used a resin to secure the wire into the coil or plug cap.
You'll find the resin that I'm talking about on items such as the bottom of coils,cdi boxes,heat sinks,etc....electronic stuff.
I have no idea why that was done by the factory and I've only seen a few in the 30 years that I've been using Rotax.
I've had several Rotax certified repair guys look at me like I was crazy when I mentioned the issue to them....and then when I hand them the coil assembly their faces tell the story.

If you have a assembly that has resin....you're not going to get it apart without damaging something.

As old as the engine is though....I would guess that the wires are just being stubborn and are stuck.
Try hitting them with some lube that is electrical compatible....soak them for a bit.
If you cant get them out of the coil try getting the plug cap off and work from that end of the wire.

Wish I could be more help but I almost need to have it in my hands to help you....

And just some advice.....due to the age of the engine and componants,it probably wouldn't be a bad idea to replace the plug wire and plug cap just for good measure.

Kevin
 

Armilite

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Joined
Sep 5, 2011
Messages
3,318
Location
AMES, IA USA
Can some one tell me how to tell the year of Manufacture from the serial NO. on the engine. I have an engine that has never been run, plastic plugs still in place, with no identifying sales information.
Have no idea what shelf life is!
Thanks,
Johnc
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Look on the Cylinders there should be a Casting Date, like a 92 Casting Date would be a 1993 Engine. You first had Non-Provision Engines, then Provision 4 Case Engines, then starting around late 92 they went to Provision 8 Case Engines till they discontinued them. The Snowmobile 503F was discontinued in 2003 when they introduced the New 550F. The 277F 380F and 440F were discontinued about 2006-08.
 
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