Official Details of SKUSA \ IAME's 175cc Shifter

As was teased at the SKUSA Supernats in 2017.…Official details of the 175cc shifter that IAME, SKUSA and Lynn Haddock have been working on. I think this is going to be make or break for SKUSA, it’s a BIG departure from other offerings.

The Skim (press release and more pics below):

  • Coined as the IAME SSE
  • 175cc, 49HP at 13,000, 27ft lbs at 12,500
  • Available for purchase from August 2018
  • Competition introduction: SKUSA 2019 winter series
  • Freeze on technical regulations (Unspecified period of time however)
  • Introductory price 3655.00 USD


Press release

IAME Skusa Shifter Engine Details

23 MAY 2018 – Superkarts! USA (SKUSA), in conjunction with IAME USA and IAME S.P.A., are excited to announce details of the long awaited release of the SKUSA shifter engine (SSE). The powerplant has been in development for several months with multiple iterations, developments, and improvements along the way. Both IAME and SKUSA couldn’t be more excited for the next evolution of the shifter platform in Superkarts! USA competition.

“It’s no secret, I’m a gearbox guy at heart,” explained SKUSA president Tom Kutscher. “As far back as the days when I drove in SKUSA myself, I’ve always enjoyed the added challenge of shifting gears. That said, finding the appropriate successor to the current engine format was something I took great care to consider and make perfect.”

Superkarts! USA entrusted longtime karting veteran, and IAME engine expert Lynn Haddock to consult on the new project. “We wanted something specific to the North American market,” clarified Tom Kutscher. “It would have been really easy to run something that already exists, but Lynn worked with IAME and Tillotson to help create something that is not only fast, it is uniquely specific to our racing formats in the states. It’s also incredibly reliable and affordable, which was one of the key motivations in the design.”

The new IAME shifter engine will make its official North American debut at the SKUSA SummerNationals in New Castle, Indiana. As was the case all season, there will again be demonstration engines on karts that qualified drivers may test drive. There will also be IAME factory representation conducting lectures and seminars about maintenance and care of the engines.

The new IAME “SSE” will be available for purchase by all teams and drivers beginning in August with an exciting introductory pricing structure. For a limited time, new engine packages will be available for the MSRP of $3655.00 USD — (normally $5695.00). The comprehensive package comes with everything for basic operation, including ignition, carburetor, pipe, inlet silencer, and water pump with pulley. The water cooled, reed valve engine produces a staggering 49 HP at 13,000 RPM and a hefty 27 ft. pounds of torque at 12,500 RPM.

The special pricing initiative is the culmination of joint cooperation by Superkarts! USA, IAME USA West, and IAME USA East. “We recognize there’s a significant financial outlay to get into the SSE format,” remarked Eric Jones of IAME USA East. “Similar to the popular X30 trade-in program a few months back, we really wanted to offer something special to teams and drivers making the leap into the class. We sharpened our pencils to get as aggressive as we could on the pricing and make it as affordable as possible.”

The IAME SSE will see its competition debut at the 2019 SKUSA Winter Series in Homestead, Florida. The tentative plan is to introduce the engine format and classes for both ‘pro shifter’ and ‘masters shifter.’

“Entry numbers have dwindled in our national shifter program, that’s no secret,” added SKUSA’s Tom Kutscher. “The constant sentiment we hear is that people are quite honestly looking for something new. We originally had hoped to have the engine race ready for 2018, but for a change of this magnitude, we want everything absolutely perfect.”

To aide in the transition for teams and drivers, IAME is also committing hands-on personnel from the factory to be in attendance at the Winter Series debut. “It’s completely understandable that there will be a learning curve and more feedback to gather,” Kutscher said. “We want to make every possible resource available to our racers so they can get their questions answered in a timely and direct fashion. Having IAME factory representation on-hand is something we believe very strongly in.”

Similar to the popular X30 format in the United States, the new SKUSA Shifter Engine will once again have a claiming rule in national competition. Technical regulations and parity will again be of utmost priority, similar to the existing X30 single speed engines. Furthermore, there will be a ‘freeze’ on any major SSE updates or upgrades, ensuring racers have peace of mind in their investment.

“We’re taking what worked well for the X30 format and bringing that concept to the shifter engine too,” Said IAME’s Lynn Haddock. “We’ve seen the consequences of manufacturers forcing upgrades on customers. This is something we vehemently opposed from the outset. We want our racers to know their purchase will be good for several years to come.”

More details and dealer information will be available in the coming days and interested racers and teams are invited to contact IAME USA West or East to arrange priority fulfillment. Orders will be filled on a first come, first served basis. Those looking to be among the first to have the new engine are advised to place their orders early.

Superkarts! USA is North America’s premier kart racing promoter and sanctioning body. The privately held organization owns and operates regional and national kart racing series with the goal of furthering the sport’s reach and participation.

IAME – IAME is the world leader in Karting engines. After attaining nearly 50 years of history, 55 employees, over 30 models of engines from 60cc to 175cc and a worldwide network, IAME is undoubtedly the most renowned and trusted brand in its field. Motorsports’ most famous drivers began their careers in Karting, and IAME is the brand that led them to success.

SKUSA IAME SSE 175cc Shifter Photos


I’m not a shifter guy, but I am excited to see a field of these in action. Assuming you can get a full field of them at $5700 retail… Jeez.

They seem to be doing it right though. Intro pricing, frozen tech updates etc.


It’s a chunk of dough for sure, but then when you think about what a competitive (new) stock moto costs… $6k+. (We’ll leave the stories of multiples of that number aside for now)

There’s no getting around the fact that the RoK shifter is sub $4K and is a serious kick in the pants too though.

I’ve brought this up before in the previous thread here about this engine, I wonder if it’s possible to swap to a 125cc cylinder on this?

Externally, it looks a lot similar to IAME’s KZ-homologated Screamer engine. Is this basically a Screamer with a cylinder bored out to 175cc?

I understand the reasons for going to 175cc, KZ power but with less of the operating costs that KZs are known for, but are they limiting potential customer base by it not being 125cc? I can see some clubs/series/orgs not aligned, or in direct competition, with SKUSA, locking out this motor simply by specifying “125cc maximum” for their shifter classes.

That may not be as much of a problem on the west coast, where SKUSA’s influence is so strong, but it could be an issue here in the East, where there isn’t much connection with SKUSA at all. (I know they mentioned IAME East in this announcement however.)

Giving it the option of being flexible with cc displacement may make it a more attractive option.

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I only see 3 or 4 guys running shifters in the fseries races that I have been to. Maybe our tracks are too small for them or something.

Likely the more successful way to get more of these engines out, would be create a national level class with some serious prizes attached to it.

Otherwise, @KartingIsLife brings up a good point that a ROK shifter is much more affordable (and frankly, not being a shifter guy myself) I wouldn’t see the appeal over even a Stock Honda, if there is no one to race against.

I’d be more interested in using a new KTM FI 250 2-cycle motor, banishing carburetors to the past. I can’t see this being more cost effective, plus going FI helps clean up the typical 2-stroke smoky image while running on cheap pump gas.

My $0.02

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I don’t get the choices of a tillotson diaphragm carb. They generally aren’t run on shifters (diaphragm carbs), i don’t particularly know why they aren’t run without thinking about it but there must be a reason.

Other then that, anything is better then the hondas.

My take on the SSE is that’s intended for top level SKUSA competition with no plans beyond that at this point or beyond. By virtue of that, the class should have some element of exclusivity and differentiation between that of it’s peers. With the Spec Honda packages trickling down to other classes and series.

Of course that comes with it’s own risks if it doesn’t gain enough adoption.

KTM have always sparked my curiosity, especially the 250 you’re talking about.

I believe MRC (and others) have pursued discussions with KTM and the bottom line is that KTM won’t supply motors on their own. So we’d need someone willing to buy full bikes, strip them down and attempt to supply the karting market.

I honestly think development and testing of the KTM for kart application (At protour\supernats level) would be an even bigger undertaking than this 175. It’s easy to forget how much the Spec Honda has evolved over 10-20 years. Moto engines do not do well in karting competition without a lot of trial and error.

The KTM would be fine for hobbyists and track warriors (I’d be totally down to trying one), but getting it up to par in every way needed for the likes of the ProTour is something else.

Plus, for hobbyists we already have the CR125, CR80 and even the CR250. So that leaves the KTM kinda out in the weeds. Except maybe on superkarts.

I thought the F series had shifter grids in the 20s-30s? Or do you just mean stock moto shifters?

That is a very interesting point.

I can’t recall the rationale, but Tom did talk about reasons for going with a diaphragm carm it on the Winternats “tomversation”

By f-series am mean the ones I go to which are at NJMP and the Etown track. They refer to it as the State Championship whichbis a nice way of saying “club races”. The Gearup Challenge May well have a big field of shifters.

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I’ve never seen the F-Series “State Championship” get more than a handful of shifters in any of their races. The shifterkart racers seem to gravitate to the bigger “GearUp” F-Series championship.

Even then, shifter entries in the GearUp series are down significantly this year, so far. They only got about a dozen shifters combined at the last race in Pocono; there were only two Stock Hondas.

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Yeah I was thinking of the gearup series. :confused:

I’m struggling to understand what beyond possibly remapping the ECU would really be necessary, at least for sprint races. For road racing, cooling could be an issue due to long WOT stretches, but a better radiator / water pump should solve any issue there.

But I agree the naked engine supply is an issue for a series, and is unfortunate. Hopefully they will change their mind as it becomes more mainstream. There’s always the local dealer watching for a good used engine for my own purposes - or possibly the electric option.

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Off the bat you’re probably looking at a pipe that’s better suited to karting both in terms of power delivery and packaging. Once you do that, you can bet chances of pump gas are gone. (I’d be hesitant to run it anyway personally.

So you’re looking at higher octane fuel, ECU remapping (that’s a bunch of testing right there). Oil supply would need to be figured out, or re-test with premix again. Then we see what breaks electrically and mechanically when it’s punished on a kart. Figure out what the parity is like between the motors. Maybe go back to the ECU and make some measures to reduce that margin. Put technical safeguards in place to prevent EFI trickery. Etc etc.

Not insurmountable, but maybe not worthwhile.

I still want to try on on a kart.

The tilletson carb was brought in according to the “Tomverstion” was to stop people having to have a massive box of emultion tubes, needles etc and a degree in astrophysics to tune the engine.

I have 2 KZ engines, and I wish I could get into this instead, the idea of having the same amount of power with less rebuild interval and the need to know what Im doing to tune the engine is really appealing.

The 125cc verses 175cc i dont teally think should be an issue, some common sense with rules about power rather than displacement should sort it out pretty quick.

Couldn’t they just have limited the number of carb components you could use? Isn’t that how they do the rok shifter.

Don’t get me wrong, I love diaphragm/membrane carbs on a single speed. It was always my disappointment in rotax and rok that they used float carbs. But there is a reason for using float carbs on shifter karts, you need that ready to go volume of fuel and being able to adjust your carb while driving is not necessarily a benefit for the majority of shifter drivers.

Anyway I hope it works.

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I can’t even manage to peel tape off the radiator without causing a multi-kart pile up. I cannot fathom trying to adjust jetting and the like on the fly.


This thing is a LOT different to the pumpers I have seen before. I should have taken more pics when I was in Vegas, but it’s markedly different to the HR/HL style we’re familiar with.

The thought is that they won’t need any adjustment on the fly. We shall see. The idea of being able to crack the high out an eighth in morning practice is appealing.

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Ease of use, is where it is at, I hate taking apart the carby to change things

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