3 hp 127 cc performance help?

Drew Fields

New member
I have a 3 hp flathead that is stock model 80212 and was wondering if there are any compatible performance parts available that I can install or any recommended mods I can do to get hp gains ? This engine is going on a mini bike
I'm not going to say there arent any performance parts for the 3hp flathead,but i have never been able to find any for the two 3hp engines i have.. But you can go with exhaust springs on both int. & exh. a lil carb work, and bump the timing up a hair will pick it up some...


Premium User
When we used to build the mini-Indy celebrity, Shriner, and jr 1/4 midget race engines using the 3HP flatheads, we would concentrate on carb and valves/seats. You can install hi-flow valves - that'll help somewhat as well. Then we'd twist the cam and cut the deck and head to increase compression slightly. I don't recall if Dyno ground a cam for us -- (IF they did, it was the same profile as the 89-7exp - but man, it's been at least 20 years since we did these engines.)

🏁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


Unless it's for sizing issues, you honestly might be able to get a nice 5hp flatty on here for the same price you'll be spending to get any gains out of the little 3hp. Just something to think about.