starter fuse keeps blowing

[bassfisher80]

I was out on the river yesterday for the first time in my second-hand boat. It has a 1972 Evinrude 100 HP motor. As I was slowly increasing throttle to about 1/2 throttle, the motor shut off and wouldn't start. I figured out it was the 20 amp starter fuse. I replaced it and started off once again. A few minutes later it blew again. This time the fuse shattered when I tried to remove it, so with limited options, I cut the fuse holder off and spliced the wires together. I then idled back to the launch. Couple questions...

1. What are the likely reasons the fuse is blowing?

2. Is it possible I did any damage to anything running without a fuse for about 5 minutes at idle speed?

Thanks.

 

[Joe Reeves]

Re: starter fuse keeps blowing

Check that the electric starter IS NOT still running/turning AFTER the engine starts and is running. If this area is okay..........

Either there is a poor connection somewhere OR a short is developing as you apply throttle. You can check out the short by having a ohm meter set on high ohms, have one meter terminal connected to the fuse terminal end that leads to the enginer wiring harness, NOT to the starter solenoid as this would cause voltage to be applied to the meter. Have the other meter lead attached to the powerhead (ground)....... Now, start moving the throttle, various wires etc.

Having the meter suddenly swing to a full scale reading would indicate a dead short.

NOTE: Put the fuse holder back into the circuit. You don't want to chance a boat fire. Short, no fuse, smoke, fire, gas tanks, BOOM!!!