Ok for all you motorheads out their and racers too. Lets here a few speed secrets. Not all you got but maybe a few. I am sure that we don't race against each other and even if we do so what! I'll give a few away. When we first started raceing Go-Karts we ran a 5hp briggs motor in a outlaw class which ment that pretty much anything goes. 1st thing we did was replace the head with a 4hp briggs head which increased the compression. I must add that this was after the motor was lineboard to get the center of the piston in line with the crank centerline. The piston itself is a choise of the builder keeping in mind of the weight. The piston rings were placed in the cyl and .005" was honed off the inside of the rings to take away some of the tension and to lighten them All this for less drag and rotateing weight. The Flywheel had to be stock but we found a way to lighten it by removeing every other cooling fin after this was done we drilled the flywheel and filled the holes with bodyfiller and stamped the filler with 80 grit sandpaper which made it look like the castings. This was stretching the rules a little but it did work. Porting was done with a bodyfiller called All Metel which took the heat and made the porting way beter than spending a lot of time grinding. Now on the Dirt Mod I am working on now one thing we found is by turning the 2bbl. carb sideways we increased the HP by 20. A little work on the Carb base is needed and putting a Bell Crank on the linkage allows this to be a easy job. Putting the carb sideways allows the fuel to go to the center of the manifold and it gets to each cyl. more even than running it the way it would be run normaly.
Lets here a few from the rest of you
Cold Feet
