1979 15 Evinrude loss of power, rough idle

[jlsjoe]

Re: 1979 15 Evinrude loss of power, rough idle

When I switch the coils can I simply reverse the position of the two orange wires where they enter the plug connector and then reverse the spark plug wires? Do the orange wires just pull out of the connector plug?

Joe

 

[jlsjoe]

Re: 1979 15 Evinrude loss of power, rough idle

I swapped the orange wires which come from the coils and swapped the plug wires, I did not remount/swap the coils themselves as I could not see that this would make a difference. The problem remained the same, no change when top plug wire is pulled, will not start when bottem plug wire is pulled. Does this mean that the power pak is bad or did I do something wrong?

Joe

 

[jlsjoe]

Re: 1979 15 Evinrude loss of power, rough idle

I'm thinking bad powerpak and looked at them on shop.evinrude.com for about $100. I've also found them on ebay for much less that say they fit my model, size and year but have different part numbers. I'm thinking this may not be a huge issue as the part number stamped on my current power pack is different than the one listed on shop.evinrude.com. Do alot of these cross many models? The ones I'm seeing on ebay list lots of different motors as compatible.

Joe

 

[Rick.]

Re: 1979 15 Evinrude loss of power, rough idle

Boy I wish I new what to say. I just don't understand how the top plug can be clean and dry and not sparking. Normally if a plug isn't getting spark I would expect it to be very wet with oil/gas due to it being sucked into the cylinder and not being burned. Hopefully someone with more knowledge will chime in here and we can both learn something. Rick.

 

[CatTwentyTwo]

Re: 1979 15 Evinrude loss of power, rough idle

I'm in the same boat as Rick, this is very odd and I wish that I had more to add. I can't wait to here what you ultimately find as the solution. It certainly seems like you have eliminated the coil as the problem. I know that you said that the plugs were new, but it might be worth swapping them between cylinders just to be sure you didn't get the one in a million bad ones. I have no experience with the various power packs, but TD mentioned the other day that he had good luck with the CDI units available here at iboats.

 

[Rick.]

Re: 1979 15 Evinrude loss of power, rough idle

Did you try firing your motor in the dark to see if there was any sparking to ground anywhere? Rick.

 

[SS140]

Re: 1979 15 Evinrude loss of power, rough idle

^^ Yay, I made a good suggestion! 1 point for the noob!! Go me.

(laughs)

 

[jlsjoe]

Re: 1979 15 Evinrude loss of power, rough idle

I have swapped the plugs with no change, I've heard lots of stories about bad plugs on auto forums. I did notice a small amount of fuel/oil had collected on one side of the electrode area. Maybe that is all there is and I was expecting to see more. It was quite a bit darker and thicker than what comes out of the tank. The first time I pulled it it was absolutly dry. Ran it last night in the dark and I could not see any spark anywhere.

 

[jlsjoe]

Re: 1979 15 Evinrude loss of power, rough idle

Hey Guys,
I'm thinking of getting the new power pack and was wondering if you guys would do the same or keep digging? I realize there are no guarantees just looking for some input.
Thanks!!
Joe

 

[Rick.]

Re: 1979 15 Evinrude loss of power, rough idle

Success has many fathers. If it works we will all take the credit, if not just remember it was not I who pointed you in that direction. All kidding aside, JBJ said if the coils check out then look towards the power pack. He has probably forgotten more about these motors than I will ever know so I'll go with his recommendation. When you get this engine running you better post about it. So many get their motor going and never get back to the forum to say definitively what the final solution was. Rick.

 

[SS140]

Re: 1979 15 Evinrude loss of power, rough idle

Im the guy who will listen and learn what you guys teach. And in return, I will help others.

It's like a chain, you get helped, you help others. It's a good way to be.

 

[jlsjoe]

Re: 1979 15 Evinrude loss of power, rough idle

Thanks for all your help everyone. I think I'll pick up a true spark tester before I go with the power pack as a little insurance, probably a good tool to have anyway. We are leaving town for a week over the 4th of July and I'm pretty busy before that so I probably won't be doing much with it in the next week or so but I definatly will let you guys know how I come out. It would be the least I could do for all you have done for me.
Happy Boating!

Joe

 

[Rick.]

Re: 1979 15 Evinrude loss of power, rough idle

http://forums.iboats.com/showthread.php?t=328103

I can't believe yo would go on a vacation with your motor not working!! Just kidding. Yes get the spark checker and I have to say I'm still concerned about the lack of fuel mix in the top cylinder. I think it should be soaked with fuel if it doesn't fire. You might want to watch this thread as well as he appears to be going the way of a new power pack. Rick.

 

[jbjennings]

Re: 1979 15 Evinrude loss of power, rough idle

I do think that would be the logical choice, but I am NOT a real mechanic and don't really know squat compared to many here. Your observation on the spark plug in the top cylinder doesn't match what I envision is happening with your motor. I hope Tashasdaddy or F-R or some of the other real experts here will check in on your thread before you give up and get the powerpack. I think you also might try spraying some fuel mix from a spray bottle into your carb. throat while the motor is running at a decent speed with someone else driving, or as fast as you can safely do it in a barrel and see what the effect is, to try to rule out a carb. problem. If giving fuel to the carb. gives you a big power boost, it may be a carb. problem.
I like helping folks out when I can, and I do work on quite a few motors for myself and friends, but I'm no professional by far. That said, I think there's a good CHANCE it's the powerpack. I also think that you are being wise to get a spark tester that you can change the gap on. If you have weak spark on one plug, and switching coils doesn't change anything, from my meager experience it is the powerpack. I don't know what else it could be.
good luck----I'll be very interested to hear the results!
JBJ

 

[scrampbell]

Re: 1979 15 Evinrude loss of power, rough idle

Just thought I'd toss in my 2 cents...

Since you saw a weaker reading from the top cylinder on the spark tester you used I'm going with ignition being your culprit. Testing your spark at 1/2 inch gap will provide the answer.

Even though I know nothing about coils or powerpacks, it sounds like it's not the coil since the problem didn't follow the coil. The best advice I can give is to follow the "Ignition troubleshooting steps" in any service manual.

The fact that your spark plug comes out clean from this cylinder has a simple explanation if it is in fact getting fuel...... If you held your spark plug in your hand and repeatedly dipped it in clean fuel/oil mix would you expect it to turn all black and gummy? Obviously, no. If the plug is producing zero spark then there's no combustion and no reason for anything to turn black.

If, on the other hand, you get an acceptable spark from the top cylinder then I think you're probably going to have to look at the fuel delivery (which would better explain the clean and dry plug). Since the other cylinders are running I think you can rule out any portion of the fuel line that feeds all cylinders. Inspect all fuel line connections starting at the top carb and working back to the pump. Look at the Ts in the fuel line assembly that feed the top carb. Fiddle with the Ts while the engine is running and see if you can get anything to produce a fuel leak.
- If that all checks out then disconnect the fuel line from the top carb and pump the bulb to verify there isn't a blockage to the carb.

 

[jbjennings]

Re: 1979 15 Evinrude loss of power, rough idle

Just thought I'd toss in my 2 cents...

The fact that your spark plug comes out clean from this cylinder has a simple explanation if it is in fact getting fuel...... If you held your spark plug in your hand and repeatedly dipped it in clean fuel/oil mix would you expect it to turn all black and gummy? Obviously, no. If the plug is producing zero spark then there's no combustion and no reason for anything to turn black.
.

That was a very logical and simple explanation, scampbell! I didn't even think of that!
His motor only has one carb., though.
JBJ

 

[jlsjoe]

Re: 1979 15 Evinrude loss of power, rough idle

Yeah, its making me nuts to leave without having the motor fixed. And each day I'm missing the lake is making me nuts as well. Sometimes I think I should have just taken it in for service but I really hate having others do the work I can do myself. I take a lot of pride in do it yourself, not to mention the cost of someone else who doesn't get it fixed right. They usually want to get paid for each time they supposedly "fix" it.
I like the explanation on the clean plug, I had not thought of that and it make perfect sense. That part of the puzzle was really eating away at me. I figured you guys thought I was nuts or stupid or something because I just couldn't explain how that could be.
When I get the spark tested I'll post back. No one around here carries one and they look at me like I'm from mars when I ask. I've checked 2 NAPA's, Advanced Auto Parts and one other place. I'm from a small town, about 15,000 pop. I've since lost some confidence in them. They can order one for about $30 which sounds a little steep from what I've read here, especially if its not what I want. My daughter is out of town shopping today and I've told her to check for one if she can but I'm not holding out much hope there. Hopefully I can pick one up in my travels this weekend. In the meantime I think I'll go out and try the spray bottle to the carb thing. I'm climbing the walls here and I gotta do something. Hopefully that can eliminate one possible cause.
Thanks for putting up with me guys!!

Joe

 

[jlsjoe]

Re: 1979 15 Evinrude loss of power, rough idle

I just went out and ran the motor under load as fast as I could in the barrel without making a mess and as soon as I sprayed a little gas/oil in the carb it wanted to kill right away. I figure that it was flooding out and there is probably sufficient fuel being delivered from the fuel system to the the engine.

Joe

 

[jlsjoe]

Re: 1979 15 Evinrude loss of power, rough idle

I got my spark tester tonight and could not get a spark at 1/2" gap on top cyl. Tried it all the way down to less than 1/16" and still no spark. Bottem cyl. was bright and blue at 1/2". Given the coil swap did not move the problem I feel pretty confident that it is in fact a bad power pack. I've got one ordered and it may even arrive tomorrow! May get it going before I leave after all.
I'll let you know how I come out.

Joe

 

[jlsjoe]

Re: 1979 15 Evinrude loss of power, rough idle

I just finished installing the new power pack and it seems to have fixed my problem. Nice strong spark to both holes. Under load in the barrel it almost emptied it on me. I won't be able to put it in the lake until next week for a true test but I believe we got it!

Thanks to all and have a great weekend.

Joe