15 HP with no power and low rpms

[scout-j-m]

I have a relatively new to me 1982 Evinrude 15HP, model E15RCNC. I bought it based off having good compression and that the seller ran it in a barrel at low speed on top of a good price. Since I have bought it, I have checked the impeller and LU oil and both are in good shape and the motor is cooling. I rechecked compression and got 110 psi on both cylinders. I installed a helicoil into the stripped recoil starter hole and now don?t have to use a rope on the flywheel. I checked spark and both are jumping a ?? air gap on my spark tester.

The first time I tried it out on the lake I was in a 1436 flatbottom. I had previously just ran an old Sportwin 9.5 hp and got a decent 16 mph out of it on the boat so figured this one would do much better. First blast off it took off with good power and immediately bogged down to just a few mph. Back home in the barrel I rechecked everything I did prior and after convincing myself it was good I gave it another lake test on my new 1648 Alumacraft flatbottom. Same bogging, lack of power, and slow speed/low rpms as before. FWIW the Sportwin did 15mph on this hull.

This time, I rebuilt the carb. The old one was clean but the needle was sticking some. Lake tested again and got the same results. This test though I tried pulling plug wires. Pulled one plug wire and ran the motor and it ran like when both were plugged in?so I thought it might have dropped a cylinder. But then flipped it and it still ran, just slightly worse. So both cylinders are firing.

On to working on it again in a barrel at home, I pull the plug wires while it?s running at a somewhat fast neutral idle and have the same results as on the water however I notice massive arcing from the disconnected coil to the block and other coil. It does this when either plug is disconnected. Is this a sure fire indicator the coils are bad? Or should that be expected when they have such a high charge and nowhere to dissipate the energy to?

I will add I have not installed new plugs yet. They are the correct ones though in that they are Champion QL77JC4. Neither looks totally fouled although one does have some white spots on it. I know I have compression, spark (at least to the plugs), and fuel (I?m confident in my carb rebuild as I was very thorough). In all of my tests I tried pumping the primer bulb but to no avail, gas was fresh and properly mixed, and vent cap open. Does this seem like fouled spark plugs? Or does the coil arcing I mentioned indicate something else? I am buying new plugs today and ordering new plug wires too. I?m looking for advice as to what the problem may be and what to try next if new plugs and wires don?t do the trick. I definitely don?t want to go throwing money at the ignition system until I know for sure what is at fault in it, if anything.

 

[lmuss53]

Try pumping the ball while you are lake testing it. If it doesn't bog down I would suspect the fuel punp. I think it is a fuel issue rather than a spark issue.

 

[scout-j-m]

Try pumping the ball while you are lake testing it. If it doesn't bog down I would suspect the fuel punp. I think it is a fuel issue rather than a spark issue.

I tried that but it didn't make a difference. I also have clear fuel hose from the fuel pump to the carb which appeared to stay full. I guess I can still try squirting fuel/oil mix directly into the throat at wot to see what that does.

 

[scout-j-m]

I grabbed a couple of Champion L77JC4 plugs at lunch from O'Reilly's. I also got a can of Seafoam Deep Creep which I can use to spray directly into the carb on the water to see if the rpms pickup and indicate fuel starvation.

I'll probably order some plug wires on Ebay or Amazon for free shipping and faster delivery. What are the typical plug wire lengths on these motors? I assumed one is longer than the other.

 

[flyingscott]

Change your coil it is probably cracked

 

[scout-j-m]

Change your coil it is probably cracked

I'll need to double check my troubleshooting first. I'm thinking that I was getting arcing from both coils when their respected plug wires were removed from their plug. If true that would mean both were bad correct, which would be pretty unlikely wouldn't it? FWIW though, the hardened epoxy on the backside feels slightly tacky on each of them instead of smooth. Not sure if that is normal or an indicator of failure.

 

[flyingscott]

The spark still should have tried to come out the plug end of the wire. One other thing to check first, on the carburetor is the plastic cam roller is it on .and is the plastic linkage in one piece. If either of those are broke or missing the carb won't open all the way. Also double check the link and sync.

 

[scout-j-m]

The spark still should have tried to come out the plug end of the wire. One other thing to check first, on the carburetor is the plastic cam roller is it on .and is the plastic linkage in one piece. If either of those are broke or missing the carb won't open all the way. Also double check the link and sync.

I appreciate the help flyingscott. The throttle is opening up properly. I removed the low speed knob and checked the butterfly plate for full opening when I did the link and sync. I'll double check all of that though when I try out the new plugs.

 

[flyingscott]

How did you see the butterfly was opening and closing it is hard to very see because it is at the back of the carb.

 

[scout-j-m]

How did you see the butterfly was opening and closing it is hard to very see because it is at the back of the carb.

It was actually pretty easy with the low speed knob removed. It leaves about a 3/4" hole that is just slightly above the throat. I used a small flashlight inside the lower cowling and looked through the low speed knob hole from the outside. I can't be for sure it was opening 100% to fully horizontal but I would say it was 90% open for sure.

 

[scout-j-m]

Here's a short video of me pulling each plug wire while the motor is running at a fast idle. The arcing from the coils is obvious in it. Like I mentioned earlier my air gap tester is jumping a half inch gap on each plug wire, however, this has got to be an issue I would think. What do you veteran members say?

 

[oldboat1]

For what it's worth, the arcing I see is at/from the coil-end boots. That what you are seeing? I think I would just buy a couple of complete boot and wire assemblies. The oem coil boot is shorter/shallower than the plug boot, but I'm not sure that's true with aftermarket assemblies -- or important.

 

[interalian]

I've resucitated coils and plug wires by washing them with mechanic's hand cleaner - the kind with pumice, Fast Orange or the like. Work it in just like you're cleaning grease off your hands. Gets all the oils and grease off them and they work like new. Dry them completely before re-installing. Yes, I'm a cheap ba$t@rd...

 

[oldboat1]

^^seems like a good tip! (Cheap is good.)

 

[scout-j-m]

Thanks guys. I'll look them over once more but I think they are beyond saving by that method. Reason being is the "squishiness" of the resin part of the coils. I'm not sure if I mentioned that part already, but the back of the coils where they are filled with that insulating resin-like material are not hard and smooth like I think they should be. Instead they are sticky or tacky and actually can be mushed around a little by hand. I have a picture below which doesn't necessarily show what I'm trying to describe but does show they look like they maybe are slightly melted and even has left some residue on the wires. To compound on this, only one coil has a part number on it and it seems to be the original OEM coil it came with in 1982 which is now an obsolete part. It has since been replaced with OEM part number 584561. So they are likely actually 34 year old parts.

 

[OptsyEagle]

I know they don't give them away, but would buy new coils and enjoy the piece of mind.

 

[oldboat1]

think that's right.

 

[scout-j-m]

Ok.... I'm going to grab some new coil kits with new plug wires, and install them with the new plugs I already bought. I plan on buying the CDI Electronics coil kits (PN# 183-2366) unless anyone objects. OEM ones are about $15 more each. I'll bump the thread when I get it all installed and post my results.

 

[OptsyEagle]

I would buy the entire coil assembly. It is hard to figure out what exactly that mushy stuff is but it is all over the coil. Right now you are getting an arcing spark and the motor is running like crap. I would stop messing around and buy two entirely new coils. From the BRP parts diagram the part number is 0582106 and you need two of them.

Edit: It looks like your kit and my coils are the same. The only other thing to note is that both of our part numbers have changed to: 0584561. Also, you can probably save some money using the Sierra equivalent coil, part number 18-5176. I have used Sierra coils before without any problems.

 

[scout-j-m]

I would buy the entire coil assembly. It is hard to figure out what exactly that mushy stuff is but it is all over the coil. Right now you are getting an arcing spark and the motor is running like crap. I would stop messing around and buy two entirely new coils. From the BRP parts diagram the part number is 0582106 and you need two of them.

Edit: It looks like your kit and my coils are the same. The only other thing to note is that both of our part numbers have changed to: 0584561. Also, you can probably save some money using the Sierra equivalent coil, part number 18-5176. I have used Sierra coils before without any problems.

I ended up buying the oem coils you mentioned. Hopefully them along with new plug wires and plugs will solve my problems... or at least help some and allow me to narrow the issue down further. I'll post back with how the new parts perform after I get them installed.