Rotax Max Evo engine top / bottom rebuild hour interval experience


I hope to collect some experience / data from fellow Rotax Max (evo) riders.

The reason I ask, is because here in Holland we have a ( not active ) forum where I found a post about this question, but many different answers.

Some say they do a new piston every 20 hours, and after the third piston ( 60 hours ) a full rebuild.

Another guy is saying he only does 3 times 30 hours with a piston, and then at 90 hour the full rebuild. Because he only does trackdays and now competition, and gives it a bit more oil mix. ( 2,3% )

Myself, I am careful with the engine, do a couple of warm up laps, then maybe 6 pushlaps, and then I stop. I mixed the oil at 2,3%

Another question about the bottom rebuild that i can not find yet. Is the connection rod always renewed with a big overhaul? I can bring it to a friend who does balancing Motocross engines.

Thanks for your honest opinions :slight_smile:

Nobody who has an answer on this?

first off all if the crankshaft is with in the manuals limits its a good sign that maybe the connection rod is still a usable part , after measurement its your choice .

im always change them when im doing bottom rebuilds just to be sure . But I think if you got measurements from that part alone and it is with in the manufacturers limit for use you can re usit …
but as im said before i am never do ! i want a peacefull mind .

after all its a rotax engine , it is not a bulletprooff honda cr 125 …
forgive me but i love hondas also .

DIY is rare with Rotax because of the seal requirement.

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I understand, but i dont do competition :slight_smile:

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Not me either!! Just love them on a go kart . I use to ride them on mx bikes back on time at my dirt racing years . We have rotax , iame and vortex rok , alll single speed and all for weekends practice engines here in our garage .

Im just dreaming a honda cr one day

I raced pre-EVO Rotax pretty seriously but I don’t think that matters with regard to rebuilds . This is what I did; New top end every 20 hours and bottom end and top end every 40 hours.

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Thanks for the replies ! Another question that i have. How often do you renew the spark plugs? I only drive when its dry and warm :wink:

And about the petrol a question. Here in Europe at the pump we have gasoline Octane 98. Or i can get a drum with 102 for a bit more money.

What octane is best for a Rotax Max evo ?