GO KART TECH: Rotax EVO vs. Non-EVO Engine - POWER REPUBLIC

[@thetechrrangerr2392]

One Thing is for sure, the warranty is Really helpful, it saved me from an otherwise costly bill as my piston seized in the cylinder even though I had jetty’s and everything setup correctly, had it been a different engine I would have had to pay that myself even though it wasn’t really my fault. 👍🏽

[@PowerRepublic]

Yeah it’s the only one I know of. Excellent really, considering what we subjected them too

[@shanta4003]

Great job newbee after 30 years need all the info you have thanks again

[@PowerRepublic]

Hi David, you are very welcome, and thanks for tuning in and sharing the video!

[@hundelortful]

Great video! Keep up the good work. Best karting youtuber out there. 😍

[@PowerRepublic]

Thanks mate

[@warrenrefrigerationservice654]

Thanks for explanation the differences between the evo and max. You answered my question to a tee. Explain all my questions. Much appreciated. Keep the great videos come.

[@PowerRepublic]

No problem Warren, thanks for tuning in.

[@BernieTheEvilF1Ruler]

Coming from an X30 I really like the EVO- its a bit of a rocket and not that difficult to tune one you get used to it. (I like to set and forget, but the app is pretty good) The one downside not mentioned is the electrics are its weakest link I've been through 3 starter switch failures since new in 2017 - which is a killer when you go to race and it doesn't fire. I carry a backup wiring loom from the non-evo for emergencies.

[@PowerRepublic]

Paul Feely agreed. It is a weak link. Have you changed over to the latest toggle switch version? They are much better than the first ones with the rotary switch IMO

[@BernieTheEvilF1Ruler]

@@PowerRepublic They were all toggle switch versions - I go back to the rotary ones in emergencies

[@TheHazelBlue]

I’m super nervous leaving my X30 for Rotax coming next week but this comment is reassuring :)

[@PowerRepublic]

John Alexander both are great engines, you won’t be disappointed by the bottom end torque of the rotax 125 senior Max that’s for sure 😃

[@kimnielsen4343]

I just bought a MS Kart with rotax max engine.. i got it for 250 dollars the cylinder needs to be honed, it needs a electric starter it was a fucking steal. Its one of those with discbrakes on the front as well.. its a cool kart i love it 😍 cant wait to get it up and running, what a cool floor rocket 😍😍

[@PowerRepublic]

send it!

[@edwardmoore8758]

Lovely old video, thanks! For the junior class, can an old and very fast non Evo from years ago be competitive against newer Evo engines? This older generation engine will have she new Evo loom, junior ECU and exhaust system, so it’s upgraded to current spec ancillaries. Thanks in anticipation of your advice!

[@rikoophorst49]

I have a non-EVO engine, and I'm wondering whether it is worth it to upgrade the old spring-based clutch to the new spring-less clutch of the EVO engines. Do you know if thats a worthwhile upgrade?

[@PowerRepublic]

yes, 100% a great upgrade. that old clutch sucks

[@rikoophorst49]

@@PowerRepublic Awesome, thanks for super fast reply and the info! Is there any things that need to be adjusted on the engine when installing the upgraded clutch, or is basically just plug-n-play? I'd imagine maybe you'd need to adjust the engine's idle RPM, right?

[@jackmoss9838]

Great video it helped a lot but, how do you convert a senior rotax max to a junior rotax max if it's even possible. Keep up the amazing content!

[@PowerRepublic]

hey Jack, thanks for tuning in. you can buy a conversion kit which includes the cylinder and ECU for Jmax. then they bolt straight on and you are GTG

[@jackmoss9838]

@@PowerRepublic thank you so much ♥️

[@davidjeal2626]

really useful video as always, cheers! is the throttle slide in the evo carb the same as non-evo?

[@michael897]

Is it necessary to get the upgraded ignition/battery kit? Will that improve performance over the old ignition/battery kit?

[@PowerRepublic]

improved longevity as the black box is mounted close to the battery and isolated

[@jasonleslie6366]

Does the EVO exhaust pipe offer a performance advantage over the non-EVO.? Is the non-evo pipe still compliant with Rotax rules?

[@IggySport1388]

Hey no it doesn't give any performance benefit, it's only improvement in reliability and longevity.

[@PowerRepublic]

It definitely seals up better. This creates a better environment for the exhaust gas pressure waves to operate in, which is the 2 stroke engines speciality. From memory when we did the initial dyno testing when the EVO was released, I thought the Evo pipe was the winner by a small margin, but I will have to conform this for you. Overall as a package the EVO upgrades are a real game changer. It really is the sum of the parts that make the difference and not the individual components that will change your lap times.

[@nikosdrimalitis8662]

Has the power valve different setups? In simple words, do I have to adjust the power valve opening in "close" or "open tracks"? If yes how can I do it?

[@PowerRepublic]

Hey Nikos, the new EVO power valves are excellent. they work like magic. remember that they only close when the engine RPM goes below 7500rpm, so if you are at a open track with no slow corners the PV will be open the whole time anyway. If you are at a tight track or 'close' circuit, then the PV will close by itself and open at 7500rpm (or 7800rpm depending on the extra earth wire on. the harness is attached or not) regardless of your gearing/throttle position/jetting etc etc

[@santi_cabrera]

Hi there! I love your videos! Here in Argentina we run old non evo engines. My ignition coil started to fail but replacement is over 350 dollars. Are there any differences between new and used? I've tested my engine on dyno and performance is not optimal, so any improvement on accessories will be well received. But costs on this replacements makes me think everything a couple of times 😅. As new engines are not an option because they don't exist anymore, this could be an option. Thanks! Love ur work in ur channel 😀

[@PowerRepublic]

Hello my friend, thanks for the good vibes all the way from Argentina. if you could borrow a friends to try and prove that is the problems first, that would be good. then you could save up and get a brand new old style ignition. that is the best option. otherwise get yourself a second handie

[@santi_cabrera]

@@PowerRepublic Thanks for the reply! Yeah, I believe I'll buy a new one. I've tried a friend's coil in the dyno and the problem disappeared. But it's nonsense its cost 😅 Thanks again!

[@alexpino4164]

Hello and thanks for your permanent help on tuning our karts! This is Alex from Barcelona. Simple question, can I convert my 125cc Junior Max Evo engine into a Senior Max Evo changing the Cylinder? If so, what are all the parts I may need to buy? Thanks in advance and keep up the impeccable good job you have been doing all this time!!!

[@PowerRepublic]

Hola Alex, thanks mate for the positive feedback and you are very welcome. yes you can order a senior max upgrade kit. normally comes with cylinder and PV. you will need to upgrade your ECU

[@harrydowd9960]

im currently running a pre evo junior rotax engine Please can you do a evo vs non evo on the junior rotax

[@PowerRepublic]

Hey BW, if your racing in the Jmax category, then the EVO upgrades are a good thing for sure.

[@tobycase2657]

I have a rotax max pre evo and my biggest problem is the power valve, can you upgrade the power valve by itself, is so what parts will I need to buy, cheers

[@PowerRepublic]

Hey Toby, I know the old PV has issues. You will need the harness and and all the electrics. so no not really. the only thing worth doing by itself is the Exhaust system.

[@viniciuseduardo014]

Hi, does the evo engine uses different jet numbers? the app said 124, when I removed the jet off it was 168.

[@PowerRepublic]

Vinicius Pietrovski yeah mate. The EVO jets are 115, 118, 120, 122, 125, 128, 130

[@BootsJr]

so the app doesn't work for pre-Evo engines ?

[@tonyfandoux2275]

Hi, have you plan to record a video to an upgrade from non Evo to Evo rotax ?

[@PowerRepublic]

We have a few vid on evo. The upgrades bolt on the same as the new style engine. Only the colour changes

[@autisminmotorsports]

can you cover the junior evo plus the differance between long and short barrels and go through what a dyno sheet tells us. would be good to understand bottom end and top end. Many newbees don't know and would like too. All the Best Paul at Autism In Motorsports

[@MrFrederickKiller]

Is there a performance advantage with the evo over the non evo in the Tag 125 restricted class?

[@PowerRepublic]

Sarkisrulz there is with the PV bottom end power. But wth the weight difference it is pretty evens. If you are over the minimum class weight then I recommend the EVO over the non Evo. If you are on the lighter side as a driver then I think it’s almost the same either engine.

[@lmAdaam]

Hey, two questions. 1. Where is the engine number located? 2. What is the optimal temperature for a rotax 125 evo? Cheers.

[@PowerRepublic]

1 . on the crankcase in front of the clutch ring gear above the starter bendix. 2. 55 degrees

[@jakubmatusek5006]

@@PowerRepublic would say about 60

[@Chris-mi5iy]

Just out of interest, What stops water getting into that ECU connector? looks like you can see the terminals in there

[@PowerRepublic]

nothing really chris. the engines will run in heavy wet conditions, but I would be cleaning them throughly after.

[@andytaylor9618]

Hi can you put the max evo power valve on the none evo

[@chipsutcliffe7110]

Why has Rotax died in the USA? I bought my Evo in 2017, just months before the rebate program was started by ROK to give a $1500 credit towards a new Rok for trading in a Rotax. The next year there was no place to race my Rotax, and my local shop stopped servicing Rotax. (I am in California.) I just had my Evo re-built after almost 55 hours, only because it was due according to the service manual. The Rok owners are rebuilding before ten hours of use. How has Rok driven Rotax out of the USA with an inferior product?

[@IggySport1388]

55hrs on the same top end? Or did you change the piston and ring before that?

[@chipsutcliffe7110]

@@IggySport1388 The Rotax Evo manual states the following about tear down inspections: "Inspection of the following components after every 50 hours of operation: piston, piston pin and bearing cage, conrod and bearing, main bearings of crankshaft, drive of balance shaft, sealing of water pump shaft." I just replaced everything for $350 labor and about $800 in parts.

[@IggySport1388]

@@chipsutcliffe7110 ok I just wanted to know if the engine ran unserviced for all of the 55hrs before you sent it in. From what you're saying the answer to that is yes. How was the performance of the engine on the 55hr mark vs when it was new? Did you feel any decline in performance?

[@chipsutcliffe7110]

@@IggySport1388 Sorry, no work done before the re-build. I noticed a jump in performance after the re-build, but the decline was very gradual after purchasing it and it was running fine before re-build. Its hard to know for sure because everyone has gone to the Rok, and there are no newer Rotax on track to compare it with. The Rok is very different and hard to compare. But I was rarely passed on practice days by a Rok.

[@PowerRepublic]

Thanks for the great discussion. I am not sure what the go is in USA. Here in Australia the Rotax has been well supported for as long as I can remember. The IAME engines are more popular is some areas and the Rotax in others. The longest I have been for a Rotax race engine, still with great performance, was 17hrs before it had a new top end rebuild. The longest for the bottom end bearings and con rod is 50 hours. you can go longer between bottom ends, but it can stop suddenly i.e melt down so I don't recommend that.

[@davidsaez8691]

hi. do you know the KZ Modena 125 cc engine? I just bought a second hand kart with this engine, Fernando Alonso chassi (Tonykart). I got it from someone who was competing. It seems to be a very nice engine. Thanks.

[@PowerRepublic]

Hi David, I haven't had a lot to do with KZ engines, other than my own engines. There isn't a lot of people with them here. What I have seen, they are nice, great power and heaps of fun to drive. Most of the KZ's I have sen are pretty similar to work on.

[@Kmapri3]

Could i use the radiator from my pre evo for an evo engine?

[@PowerRepublic]

yepo

[@TheJerandall1]

Can the Rotax 125 dd2 engine be upgraded to Evo status with the same kit as the rotax senior max kit? Are the engines the same others then how they drive the axle?

[@PowerRepublic]

Same same but different. There is a DD2 upgrade kit specific for dd2

[@p.c.h.6721]

Hi, thanks for the video once again. Is the Rotax app for the phone reliable? It gives me a jet of 133 for my DD2 engine, but I drive with a 135 main jet and it feels better? Do you use the Rotax app for the phone, is it reliable? Just as a comment, I used to have a Rotax Max and it actually has more power from around 6000 rpm to 11500 rpm than the DD2 engine, after 11500 rpm the DD2 wins, so it was a little bit disappointing to find that out, any comments on that?

[@PowerRepublic]

Hi Silvana, I don't personally use the jetting apps of the phone. I have used them before and they work for some people, however around my local go kart track the weather is very similar most of the year and I down find the jetting that critical that I have to check the app before each session. they are a great tool if you are somewhere new as a starting point, but what I find is that I use almost the same jet at each track I go to. The one thing to look out for is major elevation changes and humidity. It seems to me, someone else can add to this if they have their own experience, that for every 200m increase in sea level you can adjust down one jet size. Also watch the percentage of humidity. If it changes by more that 30%, maybe check you app for a suggested jet change. Normally for my rotax engines, 118 main jet for lean conditions, 120 main jet for normal conditions and 122 main jet for rich conditions. Non EVO it would be 158, 160 and 162 equivalent. Yes the S max has a good kick down low, but the DD2 is far superior with it max power and gear ratios. I much prefer the power delivery of the DD2 as it just a more radical feeling.

[@p.c.h.6721]

Power Republic Thank so so much for sharing all that information. Where I drive I use on the DD2 a main jet of 135 at sea level, and 133 at another circuit that is in a higher altitude. Keep up the great videos! Cheers.

[@IggySport1388]

@@PowerRepublic Derek i find those jets you're using for senior max on Evo quite lean! We use 158/160 on pre-evo here bit I've never tried evo. The rotax app however spits out a jet of 126 under most conditions here in Trinidad. But as i say no first hand experience to verify.

[@PowerRepublic]

@@IggySport1388 yeah the EVO jets are heaps leaner than the older carbs and with a richer float level we run here the app calls for 1-2 jets too rich for our engines here.

[@IggySport1388]

@@PowerRepublic are you at sea level where you're at? If not, whats your altitude?

[@Alexandros27]

Can a i turn my 2012 DD2 to put a valve Evo kit ?

[@PowerRepublic]

yes you can

[@colinsunday9149]

Can you put the evo cylindee on the non evo dd2?

[@PowerRepublic]

Hey Col, sure can, bolts straight on

[@Willy_Wanka]

Wow dude ur making my decisions harder... Going to get a new chassis but wanted to know if I could carry over my senior max to the new chassis. Since I believe that the owner before me just renewed the engine it's in a really good condition. On top of that I have quite the weight advantage over my competitors on our local track and will therefore stick with the non-evo. Do you believe that I did the right decision?

[@PowerRepublic]

well if you are competitive with your current engine, then there is no harm to take it over to the new chassis and give it a burn. then if you are feeling like you are down on some GeeGee's, then you could update to the EVO gear. that would be the best of both worlds then.

[@Willy_Wanka]

@@PowerRepublic I see your point. This is my first karting season and I started with a used, 15 year old arrow kart chassis from Australia (damn chassis is as old as me) and there's just too many problems to the point where it's more worth to just upgrade to the one that our local track sells and supports. There are some good deals for the chassis but I feel like my engine performs quite well. On the other hand they also sell full karts with Evo engines and maybe I should put a bit more money on the table and learn my lesson from my old used kart. Thanks for the reply anyway!

[@PowerRepublic]

@@Willy_Wanka great idea, stick with your local guys with their karts as they will have all the spares handy and the track knowledge.

[@andreilapusan3015]

Guys I just bought a rotax max kart and was wondering if it is normal that I need 2 layers of tape to maintain my engine at 60 ish degrees C, when outside temperature is around 12 to 15 degrees, and it takes me 2 to 3 laps to get it to 45 degrees C . Thanks in advance !

[@PowerRepublic]

yeah that's pretty normal when the temps are low. I would do the same

[@sixtenallingersandgren6674]

Same for me

[@3scw]

What is the evo fr equivalent if it was the same scale as say f440 or lmp

[@Geopolitica1946]

Hi, im starting karting soon for first time, is a kf3 engine recommendable and is it high maintenence?

[@PowerRepublic]

Where about do you live Matiss? What is the most popular category for your age group at your local track? This is more important as a beginner because you have a lot of laps ahead of you and need some good competition to learn all the skills. The KF3 engines are a little more maintinence hungry than say a Rotax 125 JMax engine.

[@Geopolitica1946]

Power Republic i will start karting in norway, im starting simply for the motorsport passion i have, so i don’t intend on competing right away, i just have a great deal of about $800 for 3 kf3 engines and im on a budget so thats why im asking

[@PowerRepublic]

@@Geopolitica1946 the KF3 engines are a few years old now, but here in Aus they were a high performance engine class for experienced go karts. is there a beginners class in Norway? I so what engine do they use?

[@Geopolitica1946]

Power Republic rotax if im not mistaken, but my major concern is engine cost and running costs in the long run, i am 16 and i have experience with motor vehicles and motocross, my main problem is cost

[@PowerRepublic]

money and cost of things is always going to be a problem in this game. Motor racing is expensive. If there are a lot of J Max engines and that is what new guys use in Norway, save up and get one of those.. they will cost you less in the long run and are easier to use in my opinion.

[@docramyj]

Is a non-evo engine that has been retrofitted with the evo-upgrades, comparable to an evo engine?

[@PowerRepublic]

Yes but some of the latest engines have been awesome in comparison. If you have a great non Evo engine, the upgrades are going to work perfectly. Otherwise step it up to the latest package and send it

[@BLITZKRIEG1]

they need to redesign the rocker switch. my mate went off at eastern creek, picked up some gravel, and through some 1:1000000 chance a tiny pebble got stuck under it preventing him from cutting the engine off. 🤭

[@PowerRepublic]

damn. how'd ya kill the engine?

[@BLITZKRIEG1]

@@PowerRepublic waited until he got to the pits and I found a stick and pushed it out.

[@joshuawalker-harris8865]

If you needed to kill the engine you could have just pulled the plug lead off, safer than a runaway kart lol

[@vaughan9238]

lmao the same thing happened to me

[@brodyedwards3425]

Hey I'm looking at a few rotax karts to buy and just wondering how to tell the difference between a factory evo engine and an evo kit

[@PowerRepublic]

mmm factory EVO? not sure on that. All the EVO rotax engines are black with a red cylinder head cover. there are 2 variations of electronics. the first type had a twist start/stop rotary button and the latter type has a rocker style start/stop switch. hope that helps?

[@bradleydavies-calder7864]

Hi I have a kf3 and I’m looking to changed the internal water pump to a external one so like the x30’s have, Will this work fine or will I have overheating issues?

[@PowerRepublic]

Hey Bradley, shouldn't be a problem. If your only running the engine for fun and aren't class racing, you could use a 12volt electric pump.

[@bradleydavies-calder7864]

Hi! Thank you for replying, it’s only abit of fun so I will properly end up running a 12v pump, I won’t have the problem with the water pump seals going if I have an external pump as I’ve heard the kf engines are terrible for it

[@PowerRepublic]

@@bradleydavies-calder7864 Yeah that was a bit of an issue. Great motors otherwise

[@bradleydavies-calder7864]

Apart from that it seems good! Keep up the good videos!

[@riccardoarici]

So on the rotax max non evo I should set the valve to open always at 7500 rpm or it depends?

[@978matty]

All depends on other kart factors, the EVO engine adjusts itself, doesn't always open at 7500.

[@riccardoarici]

@@978matty 2:50 he said "magically it opens at 75000 rpm"

[@978matty]

Yep, the ECU controls when it opens, he was probably referring to a base line of 7500? I know mine changes and you can feel it.

[@IggySport1388]

Riccardo thats the aim, but what Derek is explaining is that it wont always open there based on a number of factors, with the new PV it is electronically controlled solely off engine rpm, so it WILL open at the correct time ALL the time hence giving more consistent performance whereas the old one is a little hit or miss

[@PowerRepublic]

Yeah that right, the electronic PV is perfect. under 7500 the valve shuts and stays shut until the revs increase over 7500rpm. This is what gives the EVO such awesome bottom end power off the slowest corners. The original PV on the Non-Evo wasn't as effective. Because it was operated by the exhaust gas pressure, the gearing/jetting/throttle position/chassis settings etc all effected how much pressure the bellows received. Now as the only way to tune the older PV was with the spring resistance pressure, it was difficult, but not impossible to keep the PV closed under the 7500 rpm limit. Once the engine reaches 7500rpm however, the Power Valve has to open or your mid range and top Horsepower really suffered. So as you can see it was a real balancing act.

[@coleia4138]

There is only a few mph difference between the two as I was racing my cousins who has a evo

[@PowerRepublic]

Hey Cole, yeah the EVO is much better down low. If your the same weight, the EVO should smash older senior max

[@nilsonfilho5281]

lancia evo

[@romannicolai3628]

Absolutely pointless, the rotax engines are limited rubbish anyway, too add that tiny tiny power on the exit of the corner is pointless, just change the gearing to get off the corner! I went no faster in an Evo than a non Evo, in fact it went wrong, it was frustrating and a waste of money

[@SRKarting]

Rotax Max, The most boring / dis-engaged feeling kart engine ever created. I tried one once, What a bunch of crap. Ive absolutely no idea how anyone can actually think these are enjoyable fun engines to drive. 100cc direct drive engines all day long.