Rotax Evo updates

Does anyone know where I could find a list of the updates that have been done to the evo over the years?

Some are obvious (battery box, ECU position) but some are not(cylinders,pistons) so I’d like to see what’s worth getting.

Thank you

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There were new cylinders from 2018. 2 new versions of the conrod since 2015, now new reed valves from 2020, new piston types from 2018 or 17 i think. This should be it

Thank you. Sounds like they all would make performance differences. Wonder if shops sell new bare motors (no exhaust, are box, carb, rad)

The conrod/piston change is mainly to the end of longevity. New conrod has more oil supply slots, the piston profile has been altered again to extend piston life.
The thing that gives the performance boost is the cylinders. From 2017 new 3d printed cylinders were released for junior. The same came for senior from 2019.

Rotax has always had issues with performance parity over the years, some cylinders were absolutely superb, some were just ok and then there were some that absolutely sucked. With the new cylinders they claim to have rectified this and that if you had a mediocre/sucky cylinder prior and you pick one of these new 3D printed cylinders up it’d straight away bring the performance of your engine up to par with the best engines out there.

I’ve actually validated this to some degree albeit my sample size is incredibly small. I have one of those older superb cylinders and I’ve used my mychron and race studio analysis which gives an engine rpm analysis. Basically this calculates on track hp/tq. I did it for my engine and a 2019 senior, sure enough the 2019 engine was on par with my known fast engine.

1)3D printed cylinder? What am I missing here. Is 3D printing not plastics and polys?

2)could I purchase a new a cylinder and put it on my older evo?

Thank you

You can 3D print almost any material to an extent including steel and alum.

That said, I think these cylinders were more so CNC machined/ported vs 3D printed.

See link below

https://www.rotax-kart.com/de/Community/Newsroom/2018/100-ADVANCED-CYLINDER-MANUFACTURING-TECHNOLOGY-FOR-ROTAX-125-MAX-and-125-MAX-DD2-ENGINE

Yes you can purchase one of the new cylinders and put it on any engine…evo or non evo

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I think thats a 3d printed sand casting. It’s awesome but it’s not the metal being printed.

It effectively allows them to have a more accurate cast, quicker and at less cost to them.

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Anyone know of a shop that still offers the 50% off the cylinder :slight_smile:

Lol that’s longgg gone… gotta pay full price now unfortunately

Hahah yes yes…looks like it’s worth it though considering it puts me on par engine-wise atleast.

I guess the piston size would be different with the new cylinder too?

Well it’d be wise to fit a new piston at the same time and do a full top end rebuild.

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