1979 140hp evinrude 2 stroke ignition problems

[daffidad]

I cooked a piston in this great running machine but more issues than I thought. Started up after the block work and ran clean for a minute or two. Then Suddenly no spark at the plug point on cylinder 1 & 3. I had power to power pak but not a plug. Not sure how to test coil so I tried power pak. Put it on and ran great for minutes then suddenly the same issue. I took the power pak from the left side which was sparking fine at the plugs and tested it on the right but no spark at the plugs. In the process of unscrewing groud screw I caught the screwdriver between the purple wire on terminal and the ground YIKES. Sparks flew it was just a millisecond but now starter wont engage nor will auto choke but I have power to it and at both solenoid posts. What to do next? Thanks for the help

 

[tashasdaddy]

Re: 1979 140hp evinrude 2 stroke ignition problems

you have 2 power packs left bank and right bank. there is an inline fuse, near the starter solenoid, small 20, you blew this fuse.

 

[emdsapmgr]

Re: 1979 140hp evinrude 2 stroke ignition problems

That fuse hides inside a red push-in rubber connector in the wiring harness. Good to keep some spares on hand, just in case.

 

[daffidad]

Re: 1979 140hp evinrude 2 stroke ignition problems

Thanks I will replace that this afternoon! Now the tougher one why am I not getting power to 1 and 3 cylinders!

 

[emdsapmgr]

Re: 1979 140hp evinrude 2 stroke ignition problems

Could be the power pack on that side. As Tas mentioned, you have two identical power packs. One drives cyls 1 and 3. Swap the two packs and see if the problem goes to cyls 2 and 4. If it does, you need a new pack.

 

[daffidad]

Re: 1979 140hp evinrude 2 stroke ignition problems

The fused fixed problem 1. I swapped the paks and cylinder 2 n 4 got great spark. no power pak issue. and no power to 1 n 3 still. Weird. I ordered the pak because of the same problem originally. connected it and got great test run and after about 10 minutes 2 n 4 cut out. the only thing I did before was removed the flywheel to cneck wiring harness for short or bare wire put a piece of electrical tape at the harness entry point to the stator. So Im not sure where to go now?

 

[emdsapmgr]

Re: 1979 140hp evinrude 2 stroke ignition problems

Probably time to check the stator and timer base output. You'll need a factory service manual and a special peak-reading voltmeter.

 

[daffidad]

Re: 1979 140hp evinrude 2 stroke ignition problems

Well she cooked for 10 minutes beautifully and then BANG. The number 4 cylinder rod cap snapped and the rod came through the side of the crankcase. Done. Oh Well.
So do I look for another 140 hp evinrude outboard 1979 and use this one for parts. Or sell it for parts and use the money for another motor altogether?

 

[Tacklewasher]

Re: 1979 140hp evinrude 2 stroke ignition problems

I'd keep it as a parts motor.

One question, do your carbs have chokes, or does it have a primer circuit? I think that is the biggest difference between the 79 and the newer model so your carbs may not move to a newer model.

 

[daffidad]

Re: 1979 140hp evinrude 2 stroke ignition problems

It has a manual choke switch on the motor. And on the ignition it has a key push automatic choke and I believe it primes at the same time?

 

[emdsapmgr]

Re: 1979 140hp evinrude 2 stroke ignition problems

Any V4 power head from 1978 through 94 should bolt right up. The shift mechanism changed on the front of the powerheads in 1987.