Plate restriction


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ok help me out here... blue, purple, black , whatever color.. as far as I have learned they are all restrictors, which has the biggest hole in order to the smallest. someone please tell me...
next, if I have a kart and want to put a kid in it, can I just put a smaller plate to slow them down??? or will I hurt my motor. Very new to this...
Are we talking flatheads, animals, clones???

There are a variety of plates, and don't assume that the color designates equality from one engine application to another. (That would have made too much sense.) :)
Then there are the IKF vs WKA plates. A LOT of variables before I can accurately answer your question.

As far as reducing plate size affecting your engine...obviously, it will reduce the volume of air thus reducing power output. WIll it hurt your engine? Possibly (especially if you don't re-jet the engine for the appropriate plate. Other changes that a builder would want you to consider would be changing the exhaust system, ignition timing, spark plug heat range, tape on the cylinder shroud, valve springs, and more.

Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cuts

Celebrating 25 years of service to the karting industry



2A supporter
and that answers a lot of it... each organization having their own plates..

206 doesnt use plates the Jr's have a Jr206 that uses different slides in the carb, and there is only one set of rules for it and that is the set briggs puts out, your not allowed to do very much to that motor


The Jr LO206 also uses a different PVL coil with a lower rev limiter ( 4600 rpm? ). The Sr. LO206 has the 6100rpm rev limited PVL coil.


New member
Yes, and no.

Yes, the Briggs rules use restrictor slides.
"Some" tracks have chosen to use animal restrictor plates for whatever reason.

A restrictor plate on a LO206 ? So here we go all over again.
Tracks making their own rules off of the rules that were established in order to control some of this , keeps up that way it will end up like the clone. Pipes , flywheels clutches etc.
This is the nonsense that needs to stop.
LO206 should be just that LO206 , not some modified version that someone dreamed up.
Some chassis (Microds) have limited room for their exhaust, and thus allow a different exhaust system. Should we not allow those guys to use the rest of the Briggs rules?

I don't like kart tracks dictating their own rules differently than the Briggs rules either, but keep in mind, it is THEIR track - there's not much you can do about it.
I've also seen where tracks are allowing disc clutches in their LO206 class as well.

I agree that it's important for the integrity of the class (nationally) that each track adopt with strict adherence, the Briggs rules. There certainly are exceptions out there.


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LOVE all the back and forth from the masters of karting :)
truly the reason I asked about he R-plates is because I wanted to also let me kids drive it... so what I need to do is invest in another kart with a "jr206". No track rules as we don't have any rules yet... trying to build with in the confides of what is common and central to the classes without going off the reservation. KISS.. as I have been told..
Not necessarily. How old are your kids? The JRLO206 is designed to be used on kid karts (4-7 year olds at most tracks.) We ran one with my youngest son for a couple years and loved it. If your kids are 8 or older, then they would be terribly bored with the 4100 rev limiter.
You use the same 6100 rev limiter coil in both unrestricted adult class LO206s as you do in many of the junior classes (simply change out the slides if that's what your track goes by.)
Some slides like the clip moved up or down on the needle, also some difference in float height may be helpful. No other changes need made.

Now, a bigger issue may be the seat size and pedal length if you are thinking of changing from adult to young child driver.


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I like that idea better, build kart to fit the driver. then limit the speed with the carb slide... more things for me to learn :) kids are all 11 or older
You can slow the kart down for the kids with the slide, or you could put a ton of gear to it so at 6100 they are only going as fast as you want them too. You could also move the throttle cable mount 1/4" so they won't be able to get full throttle.

To answer your question, I think purple is the smallest Animal plate made. A purple plate without any other changes will give them enough speed and power to get themselves into trouble!


New member
Good morning guys question I bought a kart with a lo206 and 4 spring bully scorpion clutch. Now for some strange reason when I manually turn over the crank shaft it makes a strange clunt noise like if something loose
We would need more information to go on.
It could be a rod coming loose, or simply the valves adjusted incorrectly.
If it feels like it has tons of compression - likely the compression release has broken. That's not necessarily a problem, but again, it could be the noise you are hearing.
With the L206, there's not a whole lot you can check without cutting the seals to get into the bottom end. At that point, it's no longer legal for competition. A new shortblock will set you back $300.
I would suggest taking/shipping the engine to a kart shop that works on the L206 engines. Even then, they may just short block it to be safe.

🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
Carlson Motorsports on Facebook
32 years of service to the karting industry ~ 1Cor 9:24
Linden, IN