I removed the carb from a 1986 4hp 2cyl Evinrude that had been stored for a few years. While removing the low speed orifice from the high speed nozzle ( located in float bowl section) the low speed came out with a section of very small copper tube attached. The end looked like it had twisted off and there seemed to be a small peice of tube left in the carb throat. I soaked the body in acetone and later when I went to remove the broken off piece it was missing obviously coming free and fallin off in the acetone. I ordered a new low speen orifice and high speed nozzle expecting the tube to be part of the low speed orifice. The new parts did not have the tube and the parts diagrams do not show this tube. I assembvled the carb anyway and the motor starts and runs well at anything over 1\4 throttle but under that it stalls. If I add a bit of choke it will run at a lower rpm but still not idle so I beleive it is definately a fuel problem. If I look into the carb throat I can see a small tube of the same diameter coming down from the top of the throat, obviously part of the adjustable idle screw system. My question is does the low speed orific also require the small tube into the carb throat and if so how do I find one? Was the broken tube part of the throttle body and do I have to find another complete carb? I'm stumped.
