X100AC (Now x125) From Italian Motors - 100cc Aircooled TAG Kart Engine

The trend of 100cc aircooled motors continues. This time with Italian Motors’ X100AC, which joins IAME’s KA100 and Vortex’s VLR100

While it’s an interesting take with some distinguishing features, I can’t help but think we’re seeing a repeat of what happened with TaG here.

A turf war between multiple manufacturers/distributors causing fragmentation across the US. Result being racers get pigeonholed into running certain events, based on the manufacturer or buying more than one make of motor.


Here’s the details on the X100AC


In short

  • $2495
  • 100cc aircooled with balance shaft.
  • Larger
  • Reed valve induction.
  • Tillotson 24mm carb (Unspecified Model at time of posting).
  • One piece exhaust system.
  • Bridged exhaust port, 173deg max timing.
  • Convertible to 125cc in water or air cooled format.

In their own words…

It is in our DNA – This is how president of Italian Motors Claudio Valiante describes his passion that led him towards newest project. After launching the successful X125 engines 4 years ago, and the love of the old school 100cc engines, the IM Team is proud to introduce the X100AC.

Why is this engine so appealing? For one it features a balancing shaft that reduces vibration, improves driveability and ultimate durability. Other features include 40x25x7 Main Bearing (with a same-size roller bearing upgrade available) and 20mm Crankpin. Valiante’s creativity has led to the one-piece exhaust system, a simplified wiring harness and removal unnecessary parts from the package. What truly makes this engine unique is the option to convert from 100cc air-cooled into a 125cc air-cooled or even water-cooled as all three engines will utilize the same bottom end.

Bringing together decades worth of engine experience as well as being an innovator, the designing of the air-cooled X125 variant was a fun challenge for Valiante. “We have a lot of history with air-cooled engines. Incorporating our accumulated expertise has led us to design an amazing air-cooled engine package.”

The new X100 complete engine package retails for $2495 USD and includes everything needed with the exception of the engine mount. An “Engine Only” option will also be offered for individuals looking for a core engine without accessories.

From someone who lives in this corner of the world, I do want to know why this is happening again. Its like X125 2.0 (or 1.5?)

2500 is not a ton of money (Although compared to the KA100, it seems steep). It’s just a ton of money for an engine you have to fight tooth an nail to get in a class.

If there were 50 racers in classes all over, that were running the engine, I’d could maybe see it.

But I feel like they’ll be 5-10 at the local track, and then other series will look at the KA100, and even wonder why this is a thing.

Hell, I could be wrong, but it looks like a product that the market didn’t ask for, at a price that’s too high compared to competitors.

I could get an X30 for $500 more and race in series all over the country.

Sigh… I’ll just stick with IAME.

Edit: It all depends. If it’s a local engine, that is just running at a local track, then who cares. But, especially with new karters, I wish they had fewer options to confuse them. I had that experience when I bought an X125, and couldn’t get rid of it fast enough when I tried to race it anywhere, but Sumas. Was not a fun experience.


This. So much this. Like I’ve said in previous threads, I’m still running the KT100 and think it’s a good step between 206 and TaG. With how fast the KA is, especially in the hands of proper driver, might as well just pick up an X30 and race anywhere.

Don’t get me wrong, I’d love to test drive one.
If they sold engines at their local tracks, and can get it to be popular, more power to them.

But for the price, and the available options around, it doesn’t really make sense to me.

Agree 100%! I guess I will just have to wait and see what happens with these motors in my area. KA numbers haven’t quite increased like I would have thought.

How many kart engines are sold every year? I can’t imagine the kart market is large enough to warrant the expense associated with developing and marketing this many new engines.
The last race I was at had maybe 10 in masters, 15 or so each in junior and senior. Admittedly it’s likely different elsewhere but we are talking about the NYC/Philly area which, last I checked, is densely populated. Sort of baffling how anyone involved in the business of karting makes a living at it.

I presume much like the X125, this won’t take off nationally and will be sequestered up in the northwest for club and regional events.

I really would love for some organization body to step in and establish some national rules for a 100cc class like this so anyone who wanted to develop an engine could build to a set of specs and we could actually race them all together.

Otherwise, like James said, this is just 125 TaG all over again.


I think the problem is that nobody actually has the clout, or influence to do that effectively because we have so much fragmentation. To pull it off you have to have something that universally appealing to racers and tracks\clubs across the US.

By appealing I mean incentiv$ed enough to attract those clubs and tracks to move from what they have, or at least bolt the new offering on. Even then of course you’ll still have the stick in the muds that know better, and “better” happens to come in the form of something they are selling :wink:

Single make is about the closest we’ve gotten with IAME and VORTEX’s efforts. By handling the rules, incentivizing the packages for clubs/tracks/racer and in some cases offering support they have gotten traction.

206 is probably the best example of driving adoption. It’s also an example that such adoption is a long term play.

I mean, it’s cool we have these 100cc engines and all, but from the perspective of making the sport simpler to navigate and encourage people to join (or just stay)… this is not generally helping.

Personally, I think it’s the fact that clubs really don’t think holistically enough about their regional programs to come up with something stable for racers to adopt and hold onto.

Every individual or local club is trying to look out for themselves, by selling their own package, thinking that it will spread. (Creates a ‘similar to me’ criteria) That leads to too many different motors, and then it makes it hard to create competitive parody and also hard for racers to adopt.

The Northwest also had this problem when trying to adopt the PRD. The clubs/regions couldn’t agree on a standard formula, everyone was in it for themselves, and then one group broke off and decided to start selling ROKs instead, so the whole thing fell over. Some clubs had a class for it, while others didn’t. It only really worked for lighter drivers to run as a TAG, so heavier drivers, it wasn’t an option. (The list goes on and on)

The X125 and X100AC are the same problem. It’s just a local motor, basically for Sumas and any of the vendors who sell them (which is basically Word Racing), and then the F-Series race because it got worked into the rules. Otherwise, no one knows about this engine and they don’t have a class for it, so you can’t race it anywhere.

Also, at least with the IAME , they came up with a frozen engine formula which keeps things stable for racers to adopt/learn the package with minimal costs.

Yep, this applies to classes and tires too. It’s a vicious cycle. In some cases it’s just plain rent-seeking and egos, in others it’s genuine survival.

Either way, there needs to be an incentive for a given track/club to adopt whatever formula is being proposed. Of course, if that was an easy problem to solve, it’d be done already.

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Well, it’s because every club thinks their efforts are the right one. I can’t really fault them for that, and I don’t have an answer for it, but what it does is that it makes for a horrible foundation to try to build a sustainable regional program that everyone can race with.

That’s why I ended up getting an X30 on my TopKart. I can race it everywhere, and I don’t have to worry about BS about if my engine is legal. I’ve only run into one track where they didn’t have a TAG class, and that was more because of attendance and they had created such a large PRD Spec class that it was basically TAG.

As a side note, Route 66 had 27 KA seniors this weekend, and the racing was awesome.


Personally, I think that the KA100 is the way to go, but honestly if a region would just settle on one engine to grow class, it wouldn’t matter what engine they picked.

People just need to collaborate as a group.

18 posts were merged into an existing topic: Combined 100cc Class: KA100, VLR and KT100

Some really good discussion on combining these 100cc engines, so I moved them to a separate topic.