Home Forums TaG Rotax Max How's your EVO upgrade experience been?

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    • #52088
      Eric Alexander

      So I started my EVO upgrade yesterday – having been sitting on my kits awhile waiting for some time to get to it.

      I hate to admit it, but day one did not end with me feeling good about Rotax.  I’m not sure if this is the same for anyone else, but the RAVE upgrade kit seemed to not be well-engineered.  The green valve that inserts into the pulse line seemed too large for the tubing supplied.  And the y-fitting to splice into the existing pulse line was too small a diameter for the hose I’m currently using.  It just seemed odd that I ran into fitment issues that were both too big and too small in the same kit (on the same line at that).

      Secondly, the fit and finish of the pieces leave a lot to be desired.  The carb casting is atrocious!  Also, I feel like I removed a well-engineered wiring harness and replaced it with something both cheaper and poorly engineered with all kinds of off-shoots and dangling connectors.  All the electronics are haphazardly suspended from the new mounting bracket. Everywhere I looked it seems like it was designed on the cheap.

      I don’t know, but I started to think this EVO upgrade is really a poor idea and perhaps Rotax should have retired the FR125 altogether and introduced an all-new, well-engineered EVO125.  I loved the simplicity of design in the old Rotax (even though it was a temperamental engine).  With this EVO kit, it just feels like Rotax tried too hard to fix things by adding bits and pieces – and that makes the engine a wiring and hose line mess.  From an engineer’s perspective, they just added about twice as many items that can fail on a race weekend.

      And I still haven’t gotten it out onto the track yet. =(

      Alot guys are moving to the IAME X-30 and I have to admit when I look at those engines, the engineering is impressive.  I’m one of the last of the guys at the GoPro Motorplex to stick with Rotax (and one of the only ones to upgrade my engines), but I’m starting to question Rotax’s vision. Granted, GoPro Motorplex is the East coast IAME distributor – so the perspective is a bit biased.  But its hard to look at an X-30 next to a Rotax and feel the engines are in the same league as far as fit and finish are concerned.  And that’s just on the outside.

      Anyone else feeling this?  Or, am I missing something, and when I fire this thing up next week, I’m going to “get it”?

    • #52090
      Ambrose Buldo

      It’s been a mixed bag so far.

      – It took so long for Rotax to futfill my order that I ended up buying kit from a dealer.

      – As I was pressed for time, I had dealer install it. In hindsight, to better understand the kit, I should of installed it myself.

      – We had Pre-Evo pretty dialed in tuning-wise. We used a Jetting App, and it gave us pretty accurate Plug, Pin and Jet Guidanceidiace. I’ve not found a tool that supports the EVO yet. If anyone is aware of such an application, I’d like to know.

      – First time I took it out, it would not rev past 12,300. It would hit that speed and just stall there. I left Kart with dealer to get sorted. Not how they fixed it (I think it involved installing some valve in the plumbing). Post this fix, engine pulls easily to 13,850.

      – We also changed to 120 main and IW24 plug (SR). However noticed the kart has no pull out of the very slowest corner. Old setup we were about 5500 rpm, new setup is the same rpm in this corner. It almost dies if I apply the throttle, any-way other than super slow. There is something still fundamentally wrong with engine setup. What time I gained with more RPM, I lost with sluggish bottom end. It is not a kart Gearing or setup issue. I drive our second kart with pre-evo, with same gearing and it launches from low RPM like a beast. It could be simple engine tuning, or it could be the EVO Install (Both engines are reasoanbly fresh).

      – Not a huge fan of the Battery Box, Starter Switch.

      – Once I get the engine to perform as it did previoulsy, I am sure I’ll be happier.

      – Dealer had a box-full of defective parts. I know one team who went through 3 Ign Units as they were rev limited as well.

      – I got no documention with the Kit – Anyone Know where I can find the install guide?

      – Is there an operatign manaual or do we just download the one for the EVO?

      – I find very little referance/support material on the nuances with motor.

    • #52146
      Mark Traylor


      I agree with your assessment.   everything seems cheap and poorly designed/manufactured.   We were running micro and I will say for that engine it tunes much better.  It behaves logically where as the old micro was just the opposite.   The harness is complete crap.

    • #52368
      Matt Clark

      I for one have had no problems.  I had a slight low-rpm bog, but once I installed the power valve update kit, much better.  I’ve ran multiple club races, and just ran a 3-day road race enduro with no engine issues whatsoever.

    • #52531
      Carl Beavers

      Agree with the assessments on quality and possible lack of vision from Rotax. First issue I ran into is fitting the battery box, my Arrow chassis has a seat mount where the battery box should go and my XL seat leaves little space elsewhere:

    • #52541
      Matt Clark

      Shouldn’t the battery box fit exactly where the old one did?

    • #52584
      Carl Beavers

      Well yes it would fit behind the seat, but the switch would be little hard to reach  :-)

    • #52588
      Matt Clark

      Ah now I see, just consider it pre-race yoga! :P

    • #52598
      Steve piggott

      i have the same chassie and we made a bracket for the new battery box. text me at 15106914522 and i will send you some pics

    • #52888
      John Kwong

      Here is a description on our club thread by one of our members for some of the problems and solutions experienced with  the EVO kit:


    • #53167
      Eric Alexander

      So I thought I’d add an update on my EVO experience thus far.  I’ve gotten to the track about three times and I’ve yet to really get my engines performing better than the non-Evo engines did.  I’m hitting that 12,000 rpm ceiling (which at GoPro Motorplex is a lap killer).  I’ve been progressively leaning out the jet and today I was down to 118, which is a little scary as its uncharted territory for me.  Still no top end however.

      Another thing I came across today was conflicting information regarding the pulse line feeding the RAVE valve solenoid (See this thread: http://ekartingnews.com/forums/topic/evo-pulse-line-to-rave-solenoid-which-one-is-it/). I find it hard to believe Rotax isn’t proofing this stuff, or making some in-depth explanations of what mechanically is going on.  Again, it seems as if the kits are just thrown together from parts initially designed for something else and re-purposed to work on the Rotax engine.

      Another example is this little pill added to the pulse line.  It states the pill reduces pressure and makes the RAVE valve open .5 sec later than normal.  Really?  So all this talk and power curve diagrams about the RAVE valve must open at 7600 is BS??  I mean .5 secs later could be as much as 9000-10,000 rpm.  This just reads like really poor engineering IMHO.  It should open at 7600, unless you want it to open at 7900 (remove the ground??). Or, place this pill in the line and it will open half a second later that either of those specs.  The power valve is the Achilles heel of this engine.  The EVO update was supposed to address this.  Now, I’m starting the get the feeling even Rotax doesn’t understand how the thing works.

      Okay, okay… I’m venting a little.  I really wanted to be blown away by the EVO updates and I’m a little disappointed that I’m still changing main jets all day and trying to get the engines to run well.

      On a positive note, when I hooked the RAVE pulse line up to the metal nipple on the bottom of the solenoid, the low-end power increased significantly.  I’m talking better than any of my Senior Rotax have ever run.  But with the lack of top end, I get the feeling all I did was convert my engine to a well-tuned Junior.  LOL!  But I definitely heard the RAVE valve open and the engine start to growl at close to 8000 rpm.  So I don’t know.  Is that the way it supposed to be hooked up? Which diagram is correct??  If I could get bottom end power like that and get this thing to pull to 13,500 rpm, I think I’d start singing the EVO praises.  I’m just not sure what to try next to accomplish that and that has always been the frustrating part of running a Rotax.


    • #53282
      Eric Alexander

      So good news today!  I got back to the track and applied everything I researched and it payed off!  So a big thanks to John Kwong and the Calgary Kart Club for the above link.

      The EVO kit ran strong – excellent, snappy, acceleration off the hairpin at GoPro Motorplex.  I had to dampen the E-RAVE solenoid even more to get the vibrations from shutting the RAVE valve and that fixed the 12,000 rpm limit.  The motor was simply the best Rotax I’ve ever driven today.  The track was crap – morning rain and lots of rental kart rubber making the grip low – so the laptimes were off by a few seconds.  But still the powerband improvements of the Rotax EVO was obvious.

      And to put this into perspective: I have two engines.  My main motor is a freshly sealed 2011 with an 09 head. And the other (my practice engine) is an unsealed 2004 that honestly is long in the tooth (probably pushing 40-hours).  Well today I was using the 04 motor and it was a beast.  Easily the best performance this motor has provided in the entire 5-years I’ve owned it.  And more than that, it was the best Rotax experience I’ve had.  The performance today once I hit the tuning was simply awesome.  Can’t wait to try the 2011 race engine!

      So there you have it.  I have to say the end result is very good.  The EVO upgrade was worth it.  I still think some of the engineering is a bit dodgy – like Rotax keeps adding parts to make the old dog work better.  But there’s no denying that in EVO form, the Rotax is the best its ever been.

      So now I’ll keep an eye out for what happens in 2016 once this whole EVO changeover is complete.  I hope Rotax can get everything back on track and rebuild its numbers.

    • #53820
      Eric Alexander

      I’ve been to the track three times over the past week and I have to say the EVO updated Rotax is awesome.  Still running the old 2004 motor updated to EVO and the performance difference is night and day.  I know they say the EVO kit doesn’t present a performance increase, but my 04 engine is a BEAST now.  Real usable power from 7,000 rpm on.  I’ve been dropping gears sizes and the motor just keeps pulling off the hairpin and the top speed gets faster.

      I’m really blown away by just how good my 04 motor is now.  Its significantly stronger than its ever been and requires a very different approach to driving the course.  It used to be I eased into the throttle to prevent the engine from bogging.  Now I ease into the throttle to prevent the rear wheels from spinning.

      I’m sold.

    • #53831
      Mike Bray

      I’ve not found a tool that supports the EVO yet. If anyone is aware of such an application, I’d like to know.

      There’s an app for Android and iPhone that seems to work pretty well.  It’s called “Jetting for Rotax Max Evo” and is published by ISEnet.  It costs about $7 if I remember correctly.  A word to the wise, install the plug it recommends.  If not there’s a very good chance you will leave RPM on the table.


    • #54159
      brian wilson

      Hi there, just purchased a evo rotax max senior engine and i have no idea how to wire the loom (earth wires etc)and also all the pulse lines to and from carb and gearbox etc.
      Any help appreciated

    • #54165
      James McMahon

      Here’s the owner and installation manual to get you started: http://www.rotax-kart.com/upload/files/1951.pdf

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