Smartcarb SC2 - auto air density compensation & improved fuel atomization

Even with the adjustability of the metering rod?

Yes, some had some difficulty. One particular buddy Has issues with everything so keep that in mind.

Coworker pal of mine tried a KTM 300 that had a SC2 installed in to handle cold weather riding that the stock carburetor was having jetting problems with, & said the performance improvement was immediately noticeable.

I run a TM144cc engine in the Australian superkart class. Up until now, I’ve been using the Dell VHSH 30mm and the Keihen PWM carb. With both of those, I’ve had piston failures. Now, I’ve always welcomed constructive pit chatter from my colleagues, but sometimes you receive conflicting information, but one things clear, jetting plays a big part.
So, I’ve purchased and fitted a 38mm SC2 from Corey at SmartCarb, plus 2 metering rods.
The kart runs on the stand but as yet have not taken it to the track.

Would be interested to hear from anyone running a similar set up

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I want hear how it works.

I thought there would be a compatibility issue with the VSHS vs SC inlet/outlet size variations, since the 28mm SC has the same 35mm OD outlet, while the inlet OD is 14mm smaller, but SC offer a sleeve down adapter. I thought SC was going to make kart-specific carbs, but it appears they’re sticking with the established lineup, which is probably sufficient.

I opted for the 38mm SC2 which fitted perfectly to my previous setup.
I also upgraded my mikuni fuel pump to a higher rate. Race tracks here have long straights and elevation changes.

Larger bore makes sense for RR &/or bigger tracks with longer sustained high RPMs. You’ll definitely be able to test its effectiveness in those conditions.

That would be interesting to test on KZ and SSE


After trying larger carbs on a KZ I’m convinced that the 30mm is perfect for karting. The transition response is just so nice and you lose that with larger bores. On big tracks it’s less of a thing and the bigger carbs are nice. But on kart tracks it’s hard to beat that crispiness of the 30.

The thing that gets me about the SC2 and other smart carbs is that people seem to never really get to an optimal baseline in order to reap the benefits of its “smartness”. That’s not a reflection on the carb mind you.

The one thing about the smart carb is it’s egg kinda shaped bore. So at initial opening it should act more like a smaller carb, but then benefit from the flow of a large carb at WOT.

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Very interesting! Did not realize that.

Yeah, that egg-shaped profile is distinctive & not by accident. It’s part of the formula to SC2’s performance. I’m not familiar with the setup & tuning issues of the SC, but would like to know more before committing to it.

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