New to Briggs flathead.. Need help switching to alcohol.


New member
New to the kart world, trying to get suggestions. I recently bought a used kart with a pump gas Briggs flathead for my daughter. In her class she is required to run the purple restrictor plate. I'm trying to find out what all needs to be changed to run alcohol. Any suggestions on jetting,timing and carb or carb settings would be great appreciated.


Yup. It’s not hard to do them yourself. You can use them as is with just a bigger jet in it. It’s not gonna be perfect but it will get the job done. If you are running a plate I’d try a 52 jet to start. It’s probably gonna want a little more timing too.


Premium User
Does anyone sell a carb that already has the necessary modifications done to it?
Yes, and to be competitive against purpose built purple plate flatheads it will be more than just a jet change.
A flowed blueprinted purple plate carb, purple plate cam(depends what type of track) mild port work, springs lifter, lifter bore weld up etc.
If you want to tackle it I suggest reading this first
Dont forget the max sized plate as well, crazy I know, but it ws proven some plates were larger than others
good luck


Premium User
Does anyone sell a carb that already has the necessary modifications done to it?
Got them in stock - new & used.
Small plate carbs want a small bore, rough finish, deep offset t-shaft, short & small id short stem, considerably larger metering holes, .059 or .060" jet, shallow well diaphragm, etc etc.
I think we've got as good of flathead carbs as anyone in the country, and our small plate engines have always been top notch.

Like Jamie said, if you just change a jet (or even carb) you're leaving a lot of speed on the table. Cam, pipe, ignition, springs, so much more to making power out of a small plate engine. If you're just starting out, you'll be fine for a while, but eventually, you'll want to step up your engine program to something that is built plate specific.

Feel free to drop me a note on here or give me a call. We'd be glad to help in any way that we can.

?Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
Carlson Motorsports on Facebook
30 years of service to the karting industry
Linden, IN


Like Brain said exactly...I went .058,.060 on the metering holes I run a 48 jet though she loves alot of timing.