Future son in laws rude

[sphelps]

Hey everyone , I need help on this 74 evinrude. I know as much about outboards as my future son in law.Basically nothing!
The problem is this fuse in the pic keeps blowing . It will last for a while then blow when starting. I would greatly appreciate any help with this!

Thanks S.P.

 

[mekkamaz]

Re: Future son in laws rude

That indicates you have a short somewhere. Check all your wiring and look for a stripped/damaged cable. It looks like sometimes it hits the ground shortening and blow fuse. Have a good look where cables are near or passes thru metal. Also check for the amps in the fuse...How many amps is it?

 

[daselbee]

Re: Future son in laws rude

The short that mekkamaz refers to is probably not at the engine, but up in the boat. quite possibly the key switch itself. Rig a 12v light across the two fuse terminals. Move/play with wires all thru the harness and remote and key switch...when light shines bright, you have located the short. Pay special attention to the red wire up at the key switch, the purple wire (goes hot when key is on), and the yellow/red wire.....goes hot when key is turned to start. If any of those wires has an intermittent short to ground, the fuse will blow.
Also, pull big red plug apart at engine, and check for corrosion.

 

[JB]

Re: Future son in laws rude

Got a model number??

 

[sphelps]

Re: Future son in laws rude

Thanks guys, model# 50473m
ser# E0002945
20 AMP 32 V fuse.
do you think this might be the culprit...

maybe moisture made it ground out? harness looks ok I think.

I,m gunna pick up some more fuses tomorrow and see If get it to blow .
We taped the skint up wires individually .
Thanks again S.P.

 

[nwcove]

Re: Future son in laws rude

love the heading to your post....." future son in laws rude". thought for a minute you were on the whole wrong site!! was gunna suggest "dear abbey"! lol

 

[sphelps]

Re: Future son in laws rude

Yea I thought it was a ketchy title but he,s more of a knuckle head than rude..But he,s a good guy I would,nt be helping out with his boat if he was,nt. And I don,t want to break down when I fish with him.

 

[nwcove]

Re: Future son in laws rude

future son in laws a knuckle head.......sounds like a post for the harley davidson forum! lol im sure you will good luck with the motor, and the son in law to be.

 

[LongLine]

Re: Future son in laws rude

I'd seriously consider replacing those wires rather than the tape job. Looks a little suspicious...like someone cut all three...or a sharp bracket edge took out all 3...look how they line up in the pic you posted. That engine's definitely been run in the salt a few times.

Tom B.
(LongLine)

 

[sphelps]

Re: Future son in laws rude

Thanks LongLine I pulled the insulation back on the wires there may have been broken strand or to but not cut thru. Can I splice the wires with crimps and then shrinkwrap? I hope that by isolating the wires I can tell if that was the problem. And yes salt water is the only thing we run in..

 

[HighTrim]

Re: Future son in laws rude

THose wires are corroding from the inside out. Taping/shrink wrapping them is not going to help, if it does only temporarily.

Do a voltage drop test and see what kind of resisitance you are getting through them.

 

[nwcove]

Re: Future son in laws rude

if you choose to splice , rather than replace, avoid the crimps, solder and heat shrink. ( use a solvent to remove any excess solder paste before the heat shrink, and jmo, but i like to use a bit of silicone on the joint before i put the heat shrink over it)

 

[sphelps]

Re: Future son in laws rude

THose wires are corroding from the inside out. Taping/shrink wrapping them is not going to help, if it does only temporarily.

Do a voltage drop test and see what kind of resisitance you are getting through them.

I have a meter/tester but not sure how to do avoltage drop test. This will show if wires are bad and need replacing?

 

[sphelps]

Re: Future son in laws rude

I put new fuse in today and started motor about 15 times . It never blew so maybe that was the problem. Picked up a soldering gun from H/F and will solder then shrink wrap the bad wires. Going to start it over and over and see what happens.
S.P.

 

[boobie]

Re: Future son in laws rude

Just a tid bit. When ever you solder a wire it makes it brittle and it can break easier from vibration. Best to use heat shrink terminals on both the mtr and in the boat wiring.

 

[nwcove]

Re: Future son in laws rude

with all do respect....i have never seen a wire break due to vibration at a solder joint, but i could see it happening if a butane/propane torch was used, and the joint was severely overheated before the solder hit it. but unsoldered joints, especially in a salt water used motor, will turn green and fail even with heat shrink .....in a short amount of time.

 

[sphelps]

Re: Future son in laws rude

So I guess wire nuts and electric tape is out of the question!

 

[LongLine]

Re: Future son in laws rude

I think you'll be okay for a while if you use an iron for the solder job. But keep your eye on it. I'd also check a few other wires on that engine. i.e. other tape coming loose, rub spots, etc. Make sure you have all wire positioned correctly & your cover doesn't hit anything when put back on.

Tom B.
(LongLine)

 

[sphelps]

Re: Future son in laws rude

Got the wires fixed thanks for the help . Has not blown a fuse since!

Not sure if I should have started a new thread for this question but was looking at buying a johnson 70el77s and was wondering what the compression should be on all cylinders and what should I look for in inspecting the motor. They are asking 600.00 obo.
Thanks for any input! S.P.