My neighbor asked me to help with the above engine that was given to his Grandson. The previous history of the engine is unknown and the external wiring harness is missing.
The starter is jumped directly to a fully charged test Battery. (Both 12v and ground). and throttle is wired wide open. The 12 Volts is bolted directly to the Starter cable and the battery. The ground is via jumper cable alligator clip.
With all spark plugs out (after manually oiling the cylinders and cycling them by hand) the motor turns over freely with the starter. The starter is jumped directly to the test Battery. (Both 12v and ground). The 12 Volts is bolted directly to the Starter cable (after the solenoid) .
With the compression gauge installed into any cylinder, the motor turns over for a very short interval which is always the same time duration and then stops as if the power was cut off. Disconnecting the 12 v and reapplying it repeats the symptom as many times as we tried it.
My understanding is that there are other factors(sensors) that come into play when doing a compression check with a normally connected (electrically) engine but by wiring the starter directly to the battery I thought that would not be an issue.
That all said, Is there a circuit breaker built into the starter which is tripping and then resetting when 12v is removed.? If that is the case and there is some kind of current limiter built into the circuit, How can we bypass it.? Would anything be gained by hooking the starter back up to the solenoid and using it to cycle the starter?
Can the starter be weak ? That seems unlikely to me since the starter run time interval is the same every for every application of 12v but I am not a boat mechanic so please feel free to overrule me.
Any comments/ suggestions/ procedures would be appreciated. Thanks and have a great day
The starter is jumped directly to a fully charged test Battery. (Both 12v and ground). and throttle is wired wide open. The 12 Volts is bolted directly to the Starter cable and the battery. The ground is via jumper cable alligator clip.
With all spark plugs out (after manually oiling the cylinders and cycling them by hand) the motor turns over freely with the starter. The starter is jumped directly to the test Battery. (Both 12v and ground). The 12 Volts is bolted directly to the Starter cable (after the solenoid) .
With the compression gauge installed into any cylinder, the motor turns over for a very short interval which is always the same time duration and then stops as if the power was cut off. Disconnecting the 12 v and reapplying it repeats the symptom as many times as we tried it.
My understanding is that there are other factors(sensors) that come into play when doing a compression check with a normally connected (electrically) engine but by wiring the starter directly to the battery I thought that would not be an issue.
That all said, Is there a circuit breaker built into the starter which is tripping and then resetting when 12v is removed.? If that is the case and there is some kind of current limiter built into the circuit, How can we bypass it.? Would anything be gained by hooking the starter back up to the solenoid and using it to cycle the starter?
Can the starter be weak ? That seems unlikely to me since the starter run time interval is the same every for every application of 12v but I am not a boat mechanic so please feel free to overrule me.
Any comments/ suggestions/ procedures would be appreciated. Thanks and have a great day
