1979 Evinrude 15hp repair

[coolbri70]

Re: 1979 Evinrude 15hp repair

air, fuel, compression, and spark. 1 of these is missing, just havta figure out what. now you say it wont crank, that could be electrical or the starter

 

[Jogerst]

Re: 1979 Evinrude 15hp repair

There was not a lot of gas in the tank, enough to run it for awhile, but not full. Possibly air getting sucked in when the gas sloshes around?

Last time i checked, both plugs sparked. Though they are the same plugs that were in the motor when i found it, after sitting for 15+ years.

Fuel is relatively fresh.

Compression feels alright, how can i check?

Really want to get this motor running reliably without the constant fear of being stranded.

 

[Jogerst]

Re: 1979 Evinrude 15hp repair

Also, its a 1979 and sat for 15+ years in a lakeside shed. The only things I've done are replace a wire, get the carb rebuilt, and have it tuned. Maybe I need to do more?

 

[coolbri70]

Re: 1979 Evinrude 15hp repair

i would start by checking for spark, its easy

 

[OptsyEagle]

Re: 1979 Evinrude 15hp repair

Maybe this has been covered, but what is your starting procedure. On the throttle grip there are indicators that say, fast, start, shift and slow. When starting a motor, ignore them. In neutral, move the throttle to full (up against the neutral stop). Firm up the primer bulb and pull out the choke knob if the motor is cold. Pull the starter rope a couple of times and if the motor is working well, it should fire. If you have already done this, this way, then it is something else. Good luck to you.

The other thing to check is that your throttle cam is sinq'd up correctly. The throttle roller should just touch the throttle cam at the arrow or whatever indicator is on your cam. If this is not sinq'd up right you may have some very hard starting issues and it will not be tuned well for operation.

 

[steelespike]

Re: 1979 Evinrude 15hp repair

You need to proceed logically.Get a spark checker at the auto store and confirm a strong spark. should jump 3/8 to 7/16".
Did it quit like you turned off a switch or did it struggle gradually stalling?
Struggling would indicate possible fuel supply issues.
If it has a kill switch it may have failed.In that case it might turn off like a switch.
Perhaps there is a safety lanyard that has come unhooked from the kill switch.Of course I'm
assuming it has a kill switch.
A motor that has sat for 15 years in my opinion you need to go through the fuel system from tank to carb. With special attention to cleaning. Classic fouled fuel system the motor initially runs good but gradually gets worse.
Fuel pump may have failed,may be full of gunk.
I assume when you say it "won't crank" you mean it won't run.
To me "won't crank" means you cant pull the starter or the electric start doesn't work.
One way to check fuel system is to unhook gas line at the carb put the end in a can and carefully crank the motor.
Gas should pulse strongly out of the line.This should be done outside as fumes are explosive and will flow along the ground
or floor.Also confirm all connections and connectors are tight.Be sure the connectors are on right. Years ago my brotherinlaw reversed the connector so the latch side was on the fuel supply side.
If any connection is loose or hose cracked the pump may suck air. Its possible it will suck air and not leak gas.

 

[Jogerst]

Re: 1979 Evinrude 15hp repair

Thank you to everyone for all of the help!

I took the motor back, everything fixed. Ran the motor in a barrel and it ran without problems for a good 30-40 minutes. Shifted well, didn't cut off when I had it idle. It ran perfectly. Even cranked on 2-3 pulls when cold, one when warm.

I took it out last week to scout a place for duck hunting and it cut off in the middle of the lake and I couldn't get it running again.

I have run out of solutions. I took the motor back and they went over the whole thing, said it was good and they ran it.

What else to do? New shop?

 

[bonzoscott]

Re: 1979 Evinrude 15hp repair

It sounds like the problem is occurring "after" the motor gets good and warm. You need to check for spark and fuel when this happens. I know it's rather difficult while out on a lake, but maybe you could force it to fail again (if you get it running) close to the dock and pull the boat out to make an inspection.

 

[Jogerst]

Re: 1979 Evinrude 15hp repair

Would getting it to fail while running in a barrel be the same thing?

 

[TN-25]

Re: 1979 Evinrude 15hp repair

With electronic ignition components, they can start to cut out when they get warm or hot.

I had a motorcycle that did that. I had it in to get checked out at a service facility. They ran it for an hour, but the ignition cut-out didn't happen. I picked the bike up and rode it home. I then drove it to work on a busy road. After 20 minutes it just shut off.

My point is, idling in a bucket may not be enough to bring about the component failure that you would see while cruising along under load. My coil always tested as being fine, yet it would let me down after a 20 minute run. I replaced my coil with a brand new OEM part (successively superceded part #s, hmmm... what does that say?) No more problem.

I hate to suggest replacing the CDI module on a hunch since they are pricey, but I suspect a solid state component is failing when it gets hot. It is so important if you have the ability, to test for spark right away when the motor cuts out.
This is why my 15 is a breaker-point type from 1976. Sure, the CDI give better performance, but when it goes it ultimately can mean replacement of an expensive black box.

 

[kbait]

Re: 1979 Evinrude 15hp repair

Run it in a barrel, take your daughters blow dryer and aim it at the CD box. You'll know soon enough if that's the issue.