I recently bought a 1968 Evinrude Fastwin 18 HP. This is my first "project" motor. The motor had those magnatune ignition modules and oil all over the magneto. So, I had the upper crank seal replaced and I installed new coils, points and condensors. I also cleaned the carburetor. Compression check shows an even 125 on both cylinders.
I can get the motor to idle, but it misses. If I lean it out using the slow speed needle, the RPM's increase and I can get a smooth idle. But if I run to WOT and then back down to idle, the miss or lean sneeze returns. The motor runs great at WOT, I get 18 to 21 MPH on my heavy 14 ft Sylvan.
Is it possible this problem setting the idle could be caused by a bad lower crank seal and low primary compression? By the way, the idle was a lot rougher before I had the upper crank seal replaced and cleaned the carburetor.
I can get the motor to idle, but it misses. If I lean it out using the slow speed needle, the RPM's increase and I can get a smooth idle. But if I run to WOT and then back down to idle, the miss or lean sneeze returns. The motor runs great at WOT, I get 18 to 21 MPH on my heavy 14 ft Sylvan.
Is it possible this problem setting the idle could be caused by a bad lower crank seal and low primary compression? By the way, the idle was a lot rougher before I had the upper crank seal replaced and cleaned the carburetor.