Important rules updates leading up to Grand Nationals 7

Grand National 7 will arguably be the largest 4-cycle race in many years. To ensure the most equal playing field possible, CKNA has decided to roll out two rule changes that had been planned for the 2024 season ahead of this momentous event!

Walbro carburetors:

When it was first born, Walbro was the carburetor provider for all 206 engines. Some time around 2018, Briggs & Stratton changed the included carb to one that was manufactured by them. The decision was made to allow the older Walbro pieces in the rulebook. This was done so not to force competitors to have to buy and replace a carburetor they had just recently gotten with an engine package.

Fast forward to 2023, and most of these carburetors have long since been replaced. Based on our findings, less than 5% of our entries this season came through tech with an older Walbro carb.

Unfortunately, the limited availability of an older Walbro carburetor has created the misconception by some that they are superior. Rumors of people being charged hundreds of dollars for a Walbro carb because “they need it to win” has forced us to act.

Beginning at Grand Nationals 7, Walbro manufactured carburetors will no longer be legal for competition at any CKNA event. This rules update will be included in the supplemental rules for GN7, and all subsequent CKNA Rule Books moving forward.

Thankfully, it is a very simple thing to verify you have a current, legal carburetor. If it has the Briggs logo cast into it, you are good to go! If it says “Walbro”, that part has had a good run, it is time to replace it with the updated version.

Additional Cylinder Head Checks

206 racing has become one of the largest segments of Sprint Kart Racing. There are many reasons, including the structure of the rules, affordability, parity and much more.

Unfortunately, this added popularity means that some people are always looking for an edge and start playing loose with the rules. And although the Briggs rules specify in rule 19.B “Cylinder head must be “as cast”… there have not been any measurements provided to tech officials. Often times a visual inspection is all that can be done to verify that the part is compliant with this rule.

However, both the CKNA rule book and Briggs Rule 2.5.C state that “All parts are subject to comparison with a known stock part.” 

CKNA has developed a variety of tools over the past 2 years to assist our tech officials in confirming that a cylinder head’s ports and combustion chamber meet the burden of being “Unmodified when compared to a known stock sample”. In fact, we have been testing these tools long enough to say with certainty that a unmodified cylinder head will pass these new checks 100% of the time.

Therefore we are now empowering our tech officials beginning at Grand Nationals 7 to utilize these tools to ensure that competitors or their “engine tuners” have not done anything that is against the rules. If our officials find a cylinder head that does not match a “known stock sample”, it will be grounds for disqualification.

So the question your now asking yourself is probably, “Is my head legal?”

First off, if you are racing a truly out of the box engine, and have not done any modifications yourself, the answer is yes.

If you bought your engine from, or have ever sent it to an “engine tuner” during it’s life; we recommend you reach out to them and verify they did not modify the ports OR combustion chamber of the cylinder head. 

We believe the majority of these “engine tuners” are playing by the rules, but we want to give everybody the opportunity to ensure they wont have any surprises. Grands is still 3 weeks away, so there is plenty of time to replace your head if the answer from your “engine tuner” is not what you expected to hear.


These important steps forward not only help us to ensure that Grands has a level playing field, but also that the integrity of our sport and it’s rules remain as strong as possible for years to come.

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