Dez, you have just saved me some skin !! Thanks again big fella !

Hi. I have a Rotax Max 125cc. 10years old. I woul like to change the engine piston. The dealer where I want to buy the pisto ask me the size of the piston. For that I need to take off the old piston to see the size number. Can I buy any size, it will fit on the cylinder? Many thanks. Keep with you great work sharing a lot of knowlege...

New to the kartingworld, or my son. I have the pleasure of try to learn the mechanical side. For the junior kosmic kart neutral position caster is both arrows to the front. But is it the same to have both arrows towards back ? or should I change them to neutral, both arrows pointing forward? When we bougth the used kart tyres was almost worn out. Still son was driving pretty good.Now we have new tyres...first 2 times to the track everything fine, but third time to the track the kart just slided in every corner and spinning for some reason... I´m still going to check wheel alignement ( no laser ) but can it also be that as you say in the video here that with new tyres and super grip you use negative camber? First I will check the alignement and go to track and see if helps.

Gotta come to ovrp. The beautiful karts and builds you see there. Electric builds too!

Can I put a Lo206 on a Tony kart 401R

Thanks for the video bro

Hi there Where I can order stuff like that for my go karts.. I’m in Mexico

Love your videos. Thank you for all the effort you put into making them and the good info you provide! I'm 178 cm tall and 61 kg with all my race gear. I have two Tony Karts, one with an IAME X30 S125 and Komet K2M tyres, the other with a ROTAX MAX EVO and Vega XH3 or XH4 tyres. I'm racing the UAE, so outside temperatures are typically between 30C-40C during the race season. What seat would you suggest under these circumstances?

2:32 I hate that these aren't shanked. The extra strength isn't really needed but it looks sloppy. TonyKart can do better.

Can you tell me how to check my stator on a ka100 PLEASE. no spark

Hello, I am a kart driver from Argentina. Last weekend I bought the engine with the new cylinder from a competitor of mine. Yesterday I compared it on the dyno with my engine with which I took pole position in the 2023 South American championship, the difference was 2hp at the peak. At full acceleration 6300-13500 Rpm: -My engine: 7.239 Sec -New engine: 6,762 sec I think it is a huge difference, don't waste time with the old cylinder. Postscript: the big difference starts at 8,000 rpm. Greetings my friend!!!!

We need another episode of this build!

Is this the new X30 S125 you are comparing to, or still the old model?

Hey Des, what end of the .9 to 1 scale is lean and rich? So if we’re at .85 do go richer or leaner to get into the preferred range? Odd that there isn’t a single video on KZfaq on how to actually read the data and adjust it to get to the sweet spot….

Used big ultrasonic cleaning bath. Results superb!!

Arrow kart looks innovative, striking yet strong to complete. DPE karts should be introduced to all around the world👍

What do you need to do this parts list etc where can I learn to do it?

Great video Derek, thank you. Where is the change over between the low and high jet is it rpm or load based? Or do they both play a part throughout the rev range.

How do adjust the squish? Im a tad confused!

What oil would you recommend for vortex rock GP?

Is this the same for junior rotax

Hey Des, how close should new pads be to the disk? I just put new pads in and the disk is rubbing when I turn the axle. I've moved it over in both directions and I can't get it to spin without touching. Kart is a 401R

Thank's

What if there’s no nipple bleeder on my caliper ?

Predator 224cc 4T oil recommendations

I noticed lambda placement was further along the exhaust than what u u recommended in ur micro lambda installation video. What’s the best location for a rotax?

Hi. I have a Rotax more than 10 years old. Can I upgrade all of it to a 2024 Rotax? Thanks

Does anyone know if this cylinder is compatible with the Rotax 122 engine used in the Aprilia RS125?

They are pain in the arse Rotax would be best advised just to forget them!

Awesome video again 🎉

How would you charge it? my battery is out now and I dont know what to do besides having the kart on

what changes need to be made for rotax to go from open to restricted? gearing, jetting?

I would love to see a comparison with a Micro or Mini engine as well. We have a terrible 2024 engine, which especially lack topspeed. We are more than 0,5 seconds behind compared to our 2022 engine on a track where the laptimes are around 31 seconds in the Micro category.

From what I found the difference is nowhere near as big as shown in these tests. From what I found the new cylinder gives less bottom and top whilst giving more mid. Result? Lap times are pretty much the same. If you wanted to have a more accurate experiment, maybe use the same engine for both cylinders and complete the test within the same hour.

Ok you stated this isn't the same engine how is the engine bolt holes lining up. I have a engine mount that no holes line up so I need to cut some new ones I just need to know how to line it up so I know it's not going to dog walk on me then I can mark it design it cut a new piece on my CNC table but you can't follow this video because there is nothing to bolt down to no holes match the engine pattern.

In the U.K. the new cylinder has more mid and some cases less top compared to the old……no ways it 3hp…..laps are no faster this year……you have to do the dyno min Of same day if not same hour….we have had 3hp differences if we run different days on dyno.

Your video is very good and I always follow it. I have a Rotax Evo, and it's not going above 94km/h, I noticed that the valve isn't opening and closing correctly, I've already cleaned it and it's still not working. Do you think this is limiting the speed? as it reached 110km/h. What do you advise me to do? Could it be an electronic problem? Is there any electronic test that can be done? Do you have a video about this? big hug

So if you turn up the low jet to help out of the corners - does that affect the high jet (ie wind it off a bit?) or vice versa?

Derek, quick question. The data you pulled up for the engine from January, is that the same engine you swapped the new cylinder to and Dyno'ed? Same set-up etc etc?

cant wait to try mine, should only be a second slower than everyone else now lol

Ok didn't ask

honestly, the difference isn’t that much as it looks at the dyno. My 2023 engine can keep up with the 2024 cylinders. At tracks with a few slow corners in it the difference is not more then 1 or 2 tenths.

ROK gp is best tag engine.

Yeah, you can run 1 or 2 smaller sprockets with the new cylinder. Also, it needs more fuel, so the jetting also goes up by about 1 to 3 jets. Definitely felt the extra power once i switched, almost gave me a headache while driving.

any ideas how it would go on the pre evo? could be interesting how it performs

Awesome info. Super keen to see the restricted comparison

I watched a young guy do this on Saturday No good for arthrits hands tho...

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

Derk, can you put the graphic from the Vortex ROK GP in it as well..??? I think it is still more powerfull..?!

I have a 23’ senior engine with the older style cylinder, yesterday I tested my teams 24 engine with this cylinder, and holy smokes I felt it the second I drove out, definitely worth the investment