Anyone know how much to cut off the piston skirt when porting??????????? Any help is extremely appreciated!!!!!!!
If you cut into the piston skirt, start small and work your way up to where you want it, best to have a spare piston or 3, then if you go too far, just cut the nex one the same as the last improvement. Start by cutting 2 to 3 mm off the bottom of the skirt at the intake port, then test it out and decide if you want to cut out more. probably about 5mm cut off the skirt will do. Make sure you chamfer and smooth around any cuts you make.
Remember that this does effect port timing so cutting a little off may help, but cutting too much off can make it worse. if you can connect a protractor or degree wheel to your crank you can fine tune it to match your riding style and gearing etc by putting the peak power where you'll be using it.
Read the 2 stroke Tuner's guide by Gordon Jennings or the one that Alexander Graham Bell wrote, both these can be found online and I've seen links to them in this forum as well, but by following their basics you can get a real good idea where and how much to cut.
You can also adjust your power curve by indexing the piston at the top where the transfers and exhaust ports are, shaving off 0.5 to 1.5mm at the exhaust port and transfer ports can help adjust where your peak power is as well as having some effect on max rpm. Pistons are cheap so grab up a few and have fun
EXACTLY WHAT TO DO
