1975 evinrude 15hp help

[sdmerc135]

I have a 1975 evinrude 15 horse electic start that I am trying to get running right. It cranks and runs but I was having a problem with it running badly as it warmed up then it would just die. I have cleaned out the carb, replaced the coil for the top cylinder (it was getting goo everywhere), and replaced the points and condensers. Now it runs like it's not running on both cylinders. Every now and then it spits and trys to pick up for a second on both cylinders then goes back to one. I had the points set to .020 and it wouldn't start at all. I then tried setting them to .018 and it would run like the last condition mentioned above. Any suggestions?

 

[fireman57]

Re: 1975 evinrude 15hp help

When it tries to die squeeze your primer bulb or choke it a little and see if it makes a difference. If it keeps running you missed something in the carb or it is pulling air from somewhere. If it doesn't change anything then you are possibly still losing spark to one cylinder.

 

[sdmerc135]

Re: 1975 evinrude 15hp help

I did try squeezing the bulb when it was trying to die and it did nothing. From what I can tell there are 3 coils on this motor. Two for the cylinders and one under the flywheel. Is it possible that the one under the flywheel might be bad? I think the carb might could use cleaning again and I think I need to replace the main fuel supply hose to the fuel pump. I figure there might have been some trash in it from sitting so long. I already replaced the one from the pump to the carb. This motor has been sitting up for at least 3 or 4 years.

 

[sdmerc135]

Re: 1975 evinrude 15hp help

Any thoughts?

 

[fireman57]

Re: 1975 evinrude 15hp help

Sounds like you may another coil going bad. Check for spart when it runs like this. Spark should jump almost 1/2# to ground and be bright blue. If it is yellow then that coil is bad too. You might try to clean up all grounds first. If it sat for three years I would not just clean the carb but rebuild it. The kit is not very expensive. I would also replace the water pump impeller.

 

[20/20]

Re: 1975 evinrude 15hp help

Fireman57 makes a good point. I would also check all of the lines, pump, gas, tank, etc... If it has been sitting things can dry out crack get bug nest etc... I had an engine that had a small{pin point} hole in a wire that caused it to fire on only 1 cylinder. The wire was up under the fly wheel it had rubbed a tiny tiny hole into the wire and wouldn't let the spark be right. Check it over with a fine tooth comb{so to speak} I almost never found my problem.

 

[sdmerc135]

Re: 1975 evinrude 15hp help

Ok, I now found that it is intermittently running on each cylinder. Sometimes it runs on both, then it will run on the top one only or the bottom one only. I have switched out both coils for top and bottom cylinder with no difference. I am wondering if it changes from one to the other without doing anything different that maybe the coil under the flywheel could be bad. I took the plate that the points and condensers are mounted on off and inspected the wires... didn't find any knicks or breaks in the wires. Any ideas?

 

[fireman57]

Re: 1975 evinrude 15hp help

Did you clean the grounds well when swapping your coils?

 

[OBJ]

Re: 1975 evinrude 15hp help

sd....just fer grins, recheck the point setting. Sounds like they ain't open far enough. Make sure the point arm is on high cam when setting. Are the coils lined up correctly with the bosses on the arm plate?<br /><br />EDIT: And is the flywheel torqued to specs....50 to 55 ft lb.?

 

[gss036]

Re: 1975 evinrude 15hp help

Take time and read this article and maybe you can trace the links to more information. I own a 1976 9.9 Rude electric start and will be in the same predictment when & if I ever decide to run it again as it has been sitting in my barn now for about 5-6 years.<br /> http://www.pugetsoundanglers.org/Fishing Info/Johnson 9.9_15.htm

 

[chris in va]

Re: 1975 evinrude 15hp help

I'm having the same exact problem with my '77. Stutters on either cylinder then dies completely. Mine has the CD ignition module though. <br /><br />There's gotta be some common issue we're having.

 

[fireman57]

Re: 1975 evinrude 15hp help

If the spark problem follows when you swap coils then I would have to suspect a coil. did you actually check for spark when you swapped them on each cylinder or just hear it running poorly.

 

[gss036]

Re: 1975 evinrude 15hp help

If the outside of the coils are cracked, I would bet the are shorting out or spark is jumping to ground. It will make engine really run bad. That was what mine was doing, replaced the coil w/crack and that fixed the problem.

 

[fireman57]

Re: 1975 evinrude 15hp help

If you can run it in the dark you may see a spark fly while you are running it. Something has to be shorting out somewhere for you to be losing spark. When it does this pull a plug wire. If it changes the way it runs then it is not that one. If the engine does not change the way it runs then I would swap the two coils again to make sure. If the problem follows then replace that coil.

 

[sdmerc135]

Re: 1975 evinrude 15hp help

Thats what I was doing. When it would start missing I would pull the plug wires one at a time. When it would die from pulling a wire I would know that it was only running on the cylinder that I pulled the wire off of the plug. That's how I found that without doing anything different it would intermittantly miss on both cylinders. One minute it would miss on the top cylinder and the next it would be missing on the bottom cylinder. It would even miss on the brand new coil I put on it. That's why I am thinking it is something wrong before it gets to the coils. I have checked and rechecked the points setting. I really like this little motor is the only reason I keep trying to fix it. I'm just hoping it is nothing internal to the motor. I'm not so sure that the coils are lined up right under the flywheel but I tried to get them flush to the bosses they are mounted on. There's not a whole lot of slack to move them back and forth.

 

[fireman57]

Re: 1975 evinrude 15hp help

Like OBJ asked, is the flywheel torqued properly? You may have a sheared flywheel key.

 

[herters]

Re: 1975 evinrude 15hp help

Had the same trouble (along with a few other things). Check the key for wear. A little of slop goes along way.

 

[gss036]

Re: 1975 evinrude 15hp help

Good suggestion skunk river, I helped fix an igniton problem years ago, the screw holding the points to the plate was just loose enough to allow movement, so changed the gap depending on the movement.

 

[sdmerc135]

Re: 1975 evinrude 15hp help

The flywheel is torqued. I will take it off again and check the key. I hope it is just that easy. Thanks for the suggestions.

 

[sdmerc135]

Re: 1975 evinrude 15hp help

A new flywheel key has seemed to fix it. I took it out after replacing it and it ran like a champ. There was a big difference in how easy the old one came out and how hard the new one was to get in. I guess it had some wear on it. It still looked ok though. Thanks for all of the help and suggestions. I should have started with the 68 cent key before getting a new coil and all. Lesson learned. Thanks again.