A 25 HP Yamaha made Mariner (1984) that misfires once it is warm. When initially start the motor it works fine, can even run at WOT for an extended period, but once the motor is returned back to idle, it begins to violently misfire. once it starts this behavior it persists until the motor has been setting for a long period of time, then it can be operated again for a short period.
-When the starts its misfiring there is very little to no spark on each cyl.
-Compression reads 100 on each cyl.
I believe this problem is caused from somewhere in the ignition. So i suppose i am asking the best course of action to trouble shoot the ignition system without going out and spending hundreds on parts that may or may not solve the issue.
-When the starts its misfiring there is very little to no spark on each cyl.
-Compression reads 100 on each cyl.
I believe this problem is caused from somewhere in the ignition. So i suppose i am asking the best course of action to trouble shoot the ignition system without going out and spending hundreds on parts that may or may not solve the issue.