Help with 5.5hp OB

[imported_Chrisb]

Just got a 5.5hp Johnson outboard model CD-20C.

It will only start and run with the throttle in the fast position. It seems to be running at about idle speed. As soon as I turn the throttle back it dies.

I have taken the carb apart and cleaned it. Still has the cork float. If I turn the lower carb screw all the way in, it will start to race.

Looks like a new fuel pump and fuel lines. Squeezing the primer bulb when it is runnung does not affect it.

Compression is 90psi in both cylinders. What could be wrong?

 

[Paul Moir]

Re: Help with 5.5hp OB

It sounds to me like you could have multiple problems. I think the root problem is spark though.

Check and make sure you can get both sparks to jump a 1/4"-3/8" gap. There's a common problem which will allow the spark to jump 1/16" or so, but not much further. The wider gap simulates firing under compression.

It could be that someone adjusted the carburetor way out to compensate for one cylinder not firing. The bottom screw should be out no more than 3/4 of a turn.

 

[JB]

Re: Help with 5.5hp OB

Hi, Chris.

Welcome to iboats.

I think you need to rebuild the carb, by the book, with a new float and needle. Be certain that the orifices in the carb throat are clear, even if you have to remove the little welch plugs and run a wire through them. Your kit should have new welch plugs as well as a new float and needle.

Good luck, and let us know how it goes.

 

[DJ]

Re: Help with 5.5hp OB

Chris,

Listen to Paul. He IS an EXPERT.

 

[imported_Chrisb]

Re: Help with 5.5hp OB

OK it doesn't jump that far, only across the plug. now what?

 

[Paul Moir]

Re: Help with 5.5hp OB

First, please, I'm no expert. Just a rabid amature.

If you can't get spark to jump more than a little bit, then the trouble must lay up underneath the flywheel. Commonly, the problem is that the insulation on the ignition coils cracks from age. This causes the ignition coil to arc over when stressed. It's also possible that the ignition points are dirty or out of adjustment, or even a partially sheared flywheel key. But all those components are under the flywheel so it will need to be removed.

Actually, many engines have an inspection hole in the flywheel. You access it by removing the plate on the top of the flywheel if present. Go ahead and have a peek to make sure those ignition coils are in fact bad.

There are two ways to remove the flywheel. One is to use a puller like a automotive harmonic balancer puller that acts on the three screw holes near the hub of the flywheel as such:

These screws are 1/4"-20tpi. I would prefer to see you use this method as it's the less violent one and the least likely to cause further damage.
Alternatively, there is the hammer and pry method. Use this if you must but please try to be careful. It is described on this web page, along with a very complete description of how to service the ignition components underneath it:
Click here

Tell us what you find!

 

[Scaaty]

Re: Help with 5.5hp OB

Yep on what Paul is telling you..., and I bet your coils are junk (from age). I pulled a QD 20 (59 10hp) flywheel off today, the coils were cracked big time, and still sparked. But mysterious things happen under compression (like super weak spark, if any), and a good portion of BOTH coils broke off where the plug wires go in when yanking them out.

 

[imported_Chrisb]

Re: Help with 5.5hp OB

OK I'm in and the coil insulation looks bad. I'm thinking replace everything.

How do I know what year this is so I can buy parts? It is a CD-20C sn 2326471.

How do I turn the crank with the flywheel off? I tried turning the prop and it seemed locked.

 

[wbeaton]

Re: Help with 5.5hp OB

You have a 1963.

Those coils are toast! You don't need to crank at this point. Replace those coils. It wouldn't hurt to install a tune-up kit (points/condensers) and plug wires. Once everything is installed then put the flywheel on and set the point gap. Then you can crank to test the spark.

 

[Paul Moir]

Re: Help with 5.5hp OB

Fortunately, parts are available pretty well everywhere. You can get new coils, etc, from your local Johnson or Evinrude dealer. But personally, I like the aftermarket coil 18-5181 better. Those are available from many online dealers, Iboats included, and American NAPA autoparts stores pretty cheap. Usually under $20 each.

I usually just set the flywheel on to turn the crank. You can also thread on the flywheel nut and turn that. Don't use a wrench right on the crank since it'll mar it.

Additional info - the aftermarket carb kit is not recommended. Points are fine both OEM and aftermarket though. If the spark plug wires are cracked, now is the time to replace them. Use metal core spark plug wire only though. Also, if the armature plate on which the ignition coils sit is excessively wobbly, that can be addressed right now too. The fix for that is pretty simple.

 

[wbeaton]

Re: Help with 5.5hp OB

Paul,

Can you get those coils in Canada or just across the border? I find that ordering across the border is often more expensive than my dealer. Obviously not an issue for our American firends.

 

[Paul Moir]

Re: Help with 5.5hp OB

wbeaton, check two places:
themarinedoctor.com (well worth supporting)

marinemanifold.com

My local J/E dealer wants $42 each for them, which is a little high. Marinemanifold wants $20. Carquest might have them. UAP/NAPA seems to carry a fair amount of marine gear, but seem to deny carrying any outboard stuff. I'm not certain if that's due to ignorance though.

Even with the current state of the dollar, I find ordering in Canada is much less money. Especially if stuff is sent UPS since their hidden "brokerage charge" is so high. USPS is much better but still not great.

 

[Scaaty]

Re: Help with 5.5hp OB

I get them from a independent boat shop in town for 20 bucks. See them on Ebay too, but shipping adds to the price. I pulled a 1955 QD 16 10hp flywheel off a good spark motor today. I'm parting out the good stuff, as this block seems like just a little too much Con-Rod end play. Anyway, like I said..it had a healthy spark. After you see the photo, ya wonder how it even sparked at ALL! I haven't found a good coil in a LONG time on the old Johnnys, and thats all most they needed when I picked them up, because the sellers say.."it just don't run right". DUH!

 

[imported_Chrisb]

Re: Help with 5.5hp OB

Thanks for the help everyone, Ignition parts are ordered.

How is 90psi for compression on one of these? What would it be on a "new" motor?

 

[wbeaton]

Re: Help with 5.5hp OB

Thanks guys,

I just came into a beautiful original 1954 Evinrude 25 hp electric and a 1950 Johnson 10 hp. I see ignition parts in my future.

My Napa doesn't carry outboard parts. I bought coils (among other parts) at my dealer a few months ago and I thought they were under $30, but I didn't look at the receipt. The parts total equalled what I had expected so I didn't think to check. Your right about the UPS fees, but I also just got stung an extra $9 yesterday by customs for an old tiller handle assembly I bought on eBay (sent USPS) . My $10 item was closer to $30 in the end.

 

[wbeaton]

Re: Help with 5.5hp OB

90 psi is great for that motor. They can run fine right down into the 60's. I believe 120 psi is about standard for a new motor. More importantly is the difference in compression between cylinders. You want less than 10% difference. If both your cylinders are at 90 psi then you have a strong motor.

 

[imported_Chrisb]

Re: Help with 5.5hp OB

Installed coils, points, and condensers last night and she fired right up and purrs like a kitten. Thanks everybody!!!

 

[Scaaty]

Re: Help with 5.5hp OB

Installed coils, points, and condensers last night and she fired right up and purrs like a kitten. Thanks everybody!!!

90% of all the old Johnsons that come my way just needed a set of coils. The motors are bullet proof if stored properly (not let the bearings or walls dry out). I'm not going to go back and read all the thread if posted or not, but put a new impeller in too. Not a lot of work, but you need to pull the powerhead to get at the shift rod nut to get the lower off. Use a hammer Impact Driver to break the bottom motor screws if they are rusted/crusted in. Think 4 in the back bottom, two nuts front under the carb. Not a lot of work.....just pop the fuel lines, and the silver clip up at the Mag plate linkage