2003 GTX Limited Supercharged 1503 Engine replacement

[Fightingsioux60]

I have a 2003 GTX Limited Supercharged that has a blown engine. After pulling the engine, I have come to the conclusion that it cannot be rebuilt, but needs to be replaced. The question I have is the difference between the Rotax 1503 155hp engine for the supercharged, and non-supercharged application. Can I use the components from my supercharged engine to convert a non-supercharged 1503 (i.e the engine cover, flywheel, etc)? Or are there other internal differences that make this a bad idea?

Thanks!

 

[ski-d00]

Bad idea mostly because of the pistons are different.

 

[Fightingsioux60]

Thanks, that's the information I was looking for. So there are differences in the engine platform between the 155 supercharged and non SC. If I'm buying an engine, how would I know that as the nameplates are the same? Are there other identifying characteristics?

I'm new to this, so I appreciate the insights.

 

[ski-d00]

They added a couple bosses over the years but all blocks are interchangeable with a slight modification from 05 and older to newer blocks.

 

[Fightingsioux60]

Any recommendations on where to find a good used motor that would fit my application?

 

[etemplet]

What about your electronics when trying to delete the Supercharger? Is the computer the same?

 

[Fightingsioux60]

I'm not trying to delete the supercharger, I want to make sure I get the right engine as a replacement. But you bring up a good point about making sure the ECU is correct for the engine I put in. I'm assuming you would need to change the ECU if the supercharger were removed.

 

[etemplet]

I don't understand the negatives concerning the Supercharged engines. If everything is designed properly they should be very reliable. Other than proper maintenance, which people are very lax in doing... they should last. My only question is.... "do they last". You are asking more from the engine and components but that is a design issue. Oh well for me... I've read enough and I prefer Normally Aspirated engines as 55 is my max water speed desired. Less Drama all the way around.

 

[ski-d00]

Basically, all the 4tec blocks and most of the components are the same between sc and na with a few exceptions like pistons, camshaft, ecu, and the block vent system for the new mechanical TOPS in 06. There were some nice updates like valves, sc washers, but you can pretty much interchange all years of 4tec blocks with slight modifications.

The na motors last much longer than the sc ones. They just aren't pushed as hard. Not a bad design, just the way it is.

 

[GrinchMonster2000]

Fightingsioux60

Im have the same problem now looking for a motor, parts are interchangeable from different Motors, my motor was replace with an NA longblock with the original rebuilt Supercharger got about 20hrs run time on Doo before center piston went Boom.

 

[etemplet]

Basically, all the 4tec blocks and most of the components are the same between sc and na with a few exceptions like pistons, camshaft, ecu, and the block vent system for the new mechanical TOPS in 06. There were some nice updates like valves, sc washers, but you can pretty much interchange all years of 4tec blocks with slight modifications.

The na motors last much longer than the sc ones. They just aren't pushed as hard. Not a bad design, just the way it is.

Pushing a lot more HP on the same block.... yes indeed. That will shorten the life. Almost like the old saying, "A candle that burns twice as bright burns half as long. " If you like the power though.... ROCK IT !!