cosworth
Member
I've got about 50 miles on my new motor and thought the engine would smooth out by now. Problem is that between 12-15 mph (approximately) the engine jerks. It isn't until it get over that range does it smooth out - some what. I've read the forum and have looked for a cure (i.e. O ring in the carb to seal out air, check all gaskets, tighten all nuts, played with needle positioning, went hotter and colder on the plug, went to a heavy duty chain with CNC machined sprocket and hub drive etc. I'm open to any and all suggestions