EFI always catches my interest and I’m generally bullish on it for karting… Call me an optimist.
Let’s say perceived complexity (or fear of the unknown).
“OMG O2 sensors”
Cheap and simple\complex are relative terms though. When you look at, say the Briggs 206, I suspect that EFI would increase the cost of the thing by 30% or more? That’s a hard sell to a group of customers that feel the carb is “good enough”
I personally think a basic fuel controller would have some legs… but (using 206 as an example) it’s still going to cost multiples more than the carb it comes with… so I wonder what the advantages would be for that added racer cost.
Agreed, I totally get that. EFI is about a $250-$300 option. That is significant for a $600 engine, but not so much for a $3000+ high-performance engine.
While I see electric in the next decade replacing 2 stroke TAGs and shifters for sprint tracks, that certainly is not an option for road racing when you need about a 50kWh battery to match what a 125cc shifter can do, let alone a 175 SSE. For that market we need new solutions, and there a 4 stroke EFI forced induction motor makes good sense.
I’ll add a caveat to this…
“If you know how to run and tune them and/or hire someone who does”
In the US, I’ve found that’s a very big if looking across the spectrum of people in karting.
I think some of us forget how much knowledge we’ve acquired over the years and underestimate the knowledge gap that exists.
Warped Perception converted a B&S with EFI and Turbo, it is a garage stupid and crazy built with a lot of problems. If Honda, Yamaha or somebody else can spend some time to develop a EFI small engine, it should be fairly reliable with good performance. The added “complexity” is nothing compared with the amount work you have to do with a carb. Most people on track use builder engine anyway.
A big part of the extended life of automobile engines since the carb days is improved control of air/fuel ratio. Too rich carb resulted in washing down of cylinders and wear of rings and cylinder walls. I wonder if similar on kart. Would EFI extend rebuild times?
One extreme 4-cycle example would be the Kawasaki Ninja H2R (track bike). It has a service interval of 30 hours for some engine parts such as rings and rod bearings, and 60 hours for connecting rods. “Lesser” bikes like the Hayabusa schedules seem to be 6000km for most components.
I’m specifically referring to EFI for 2 strokes, not just EFI by whatever means available. Claudio Flenghi (who was co-owner of TM Racing before his passing last year) was adamantly opposed to 4 strokes in performance karting, arguing it would wreak financial havoc due to the associated costs.
I don’t think it’s necessary nor wanted and I don’t think regulators are too keen. It’d cause an arms race in KZ (which is really their primary market), which is relatively stable and has been since 125 gearbox racing started really.
In a single-make environment it could work for 2-smokers, but that’s a different proposition. And really only Rotax have the capabilities to get something working. They were looking at it prior to EVO coming in, so something dissuaded them and they have some of the best injection tech in the business.
There was a guy running a shifter 4-stroke with the enduro racers at Blackhawk Farms 2-3 years ago. May have even been air cooled. Pribyl, Agena, Vehring - do you Blackhawk guys know him?
Those were probably “Exciter” shifters. I think it’s a package Franklin motorsports introduced. I remeber having to try and out-launch them from the line in my 80cc shifter
Definitely doesn’t help, that’s why I prefer the form factor of the pitbike\grom engines. 20HP is enough for many though… as far as the 80cc shifter equivalent is concerned.
125cc two stroke equivalent you don’t seem to have a choice but to bolt on something that you’re sure to bang your elbow off.
