Hey y'all!
Latest boat project has a 1985 Johnson 25hp that I'm trying to get running better.
The bottom cylinder is firing half as often as the top one at lower RPMS. I have a knockoff tiny tach. Wrap it around the top cylinder, reads 1,000 RPM. Wrap it around the bottom cylinder it reads 500 RPM. Obviously the engine is actually cranking the same RPM and not oscilating 500 rpms.
The bottom spark plug wire is just half the pulses. I've tried switching the coils and the plug wires. Same problem.
I'm thinking power pack or the trigger sensor? The power pack is only pulsing the bottom whole half as frequently. But is it actually the power pack or something upstream in the system (trigger sensor)?
Is there a way to diagnose and tell?
Latest boat project has a 1985 Johnson 25hp that I'm trying to get running better.
The bottom cylinder is firing half as often as the top one at lower RPMS. I have a knockoff tiny tach. Wrap it around the top cylinder, reads 1,000 RPM. Wrap it around the bottom cylinder it reads 500 RPM. Obviously the engine is actually cranking the same RPM and not oscilating 500 rpms.
The bottom spark plug wire is just half the pulses. I've tried switching the coils and the plug wires. Same problem.
I'm thinking power pack or the trigger sensor? The power pack is only pulsing the bottom whole half as frequently. But is it actually the power pack or something upstream in the system (trigger sensor)?
Is there a way to diagnose and tell?