1956 Johnson 10HP Seahorse

[STEVE IN SOCAL]

New to this forum, as well as vintage outboards...I think I got the bug.

I bought this motor for $235 today (will go on a 1950's 16' aluminum fishing boat to be used in the Sierras) It is in REALLY good shape cosmetically, and the seller was able to get it running. But after a while, it would only start for about 4 seconds, then sputter and die. It would start up again, only to sputter and die again.
The fact that it was running good (for a few minutes) steers me away from a spark/ignition problem (points, coils, etc) and the spark plugs are new. I'm thinking it may be a fuel supply problem.
Any thoughts would be appreciated...I hope to do all the work on this myself, even though I'm not a mechanic. I want to "be the motor", to loosely use a Caddyshack phrase.

Steve...San Diego, Ca

 

[Mas]

Re: 1956 Johnson 10HP Seahorse

Do not totally ignore the coils. Some will fail as they warm up but do OK when cold.

Do a compression test to see what kind of health your motor is in.

I would go through carbs however with compressed air and a very fine wire if the compression numbers are good.

Check the spark with a spark gap tester when the motor is cold and warm.

When the motor is running well. replace the water pump impeller.

MAS

 

[jbjennings]

Re: 1956 Johnson 10HP Seahorse

It definitely is a fuel problem.
However, I think it would be worth your time to start on the ignition first. At the very least to clean the points and check the spark gap which is .020 inches, looking to see if the coils are new or old and cracked/falling apart. There's a thread in the top secret files at the top of this forum. There's also a carb adjustment thread by Joe Reeves that is there as well. That's a good engine and I get a lot of good miles with mine!
Good luck,
JBJ

 

[STEVE IN SOCAL]

Re: 1956 Johnson 10HP Seahorse

My gut tells me it may be an O ring problem with the pressurized tank. The seller kept pumping up the pressure, and gas was coming out where it connected to the motor.
This motor looks like it spent more time in a garage than on the water. Other than slight paint fading and a few scratches, it looks brand new. The prop still has most of the paint on it. This makes me hopeful that the compression is good. As for pulling the flywheel to replace the coils, etc...not sure if I have those skills....
I'm also reading mixed takes on fuel/oil mix. I believe it's 24-1, but some say that the new oils today will let me use a 50-1 mix. I plan on using TCW-3 synthetic...should I stick to a 24-1 Mix?
Maybe I should hire a mechanic to do the initial coil/points/condenser and carb cleaning...any recommendations on someone in San Diego?

 

[jbjennings]

Re: 1956 Johnson 10HP Seahorse

Steve, all you need to pull the flywheel is a $10 harmonic balancer puller from autozone and 3 grade 8 bolts that are 1/4-20 threads. You can get a spark tester there for $6, too. That would be the ideal motor to learn how to play on outboards. Totally easy. You need special o-rings for that connector. I got mine at laingsoutboards.com Jim is super helpful there and will take good care of you. If you do a search there's a couple of threads that will tell you how to replace them. The thread on coils/points in the "top secret file" has pics and step-by-step directions if you're interested. I can tell you without a doubt that your motor requires 24:1 fuel/oil and you will ruin it on 50:1 Some experts will say that the '57 and '58 18hp motors have all needle or ball bearings and are safe for 50:1, but your motor is definitely NOT safe for 50:1
Do it yourself on the motor, you'll have a hard time finding ANYONE that will work on one that old, and if they do, it will cost you more than the motor is worth.
JBJ

 

[STEVE IN SOCAL]

Re: 1956 Johnson 10HP Seahorse

JBJ...I guess you're right. Fishing season is near, and I'm anxious to get it in the water.
I can't seem to find the 'top secret files' on this site. It's not like snipe hunting, left-handed monkey wrench or tobacco stretcher is it?

 

[jbjennings]

Re: 1956 Johnson 10HP Seahorse

No need to pull out the metric crescent wrench yet, Steve.
Here's a link. It's the first thread in the johnson/evinrude forum.
http://forums.iboats.com/showthread.php?t=299680

I can assure you that you can handle this motor. There's so many experts here that can all quickly help you through it. I learned all I know from the experts here on this forum, and any knowledge I can impart to you is just a regurgitation of what they've taught me. But I enjoy helping just the same.
Take a look at the topics in the thread above, they are really handy for any motor!
JBJ

 

[lindy46]

Re: 1956 Johnson 10HP Seahorse

Also, make sure your tank is holding pressure. There is no fuel pump. The pressure in the tank forces fuel into the carb. If you're leaking at the connector, you can remove it and connect both lines directly into the motor to test until you can replace the O-rings.

 

[STEVE IN SOCAL]

Re: 1956 Johnson 10HP Seahorse

I pulled the starter rope assbly off and peeked through the inspection hole. The coils look like a cracked up dried out mud flat. Looks like I'm in for the big one...

 

[jonesg]

Re: 1956 Johnson 10HP Seahorse

Yup mine were just as bad, most of the coil casing had fallen off.

I just did both coils, points, condensors and plug wires on a 1959 10hp johnson, its not so bad , just take your time. I recommend getting all the parts in one order.

I found the armature plate that the coils are mounted on had to come off too , to get the spark plug wires routed underneath, 2 screws (once I found them).

I used a seloc manual which was very usefull to keep my coca cola from spilling on the bench...otherwise...

A couple of photos before pulling it apart would have helped on assembly ,
anyways its not rocket science.

 

[STEVE IN SOCAL]

Re: 1956 Johnson 10HP Seahorse

I'll order a few impellers, o rings for the tank, and lube as well. Where's the best place to by the TWC-3 synthetic oil?
Maybe I'll check the compression first...

 

[lindy46]

Re: 1956 Johnson 10HP Seahorse

Yup - no sense wasting a lot of money on the motor if the compression is bad. I just buy the Walmart TCW-3 oil - I think it's about $11.00 a gallon. Works fine.

 

[STEVE IN SOCAL]

Re: 1956 Johnson 10HP Seahorse

Does Walmart sell the synthetic? I hear it smokes less...I have to worry about Calif tree huggers beating me with their kayak paddles

 

[rjezuit]

Re: 1956 Johnson 10HP Seahorse

I don't know about full synthetic, but there is where I buy my synthetic blend (Pennzoil). Rick

 

[jbjennings]

Re: 1956 Johnson 10HP Seahorse

On the plus side, that's why the motor probably looks in such good shape---because the coils were shot, it wouldn't run, and the owner stuck it in the garage and forgot about it. I'll bet it has good compression. I'm suspecting 85 or 90psi but maybe you got a real jewel and it'll be higher.
You can get the whole ignition for around $80.
JBJ

 

[asdasc]

Re: 1956 Johnson 10HP Seahorse

Yeah, Walmart will have the synthetic also, both in their brand and the major brands. The price of fun goes up however, to about $25 or $27/ gallon.

 

[STEVE IN SOCAL]

Re: 1956 Johnson 10HP Seahorse

Took some pics today...

It's really clean. All the rubber is good, too.

 

[coolguy147]

Re: 1956 Johnson 10HP Seahorse

ummm sure u can get the motor running but why wouldnt u be able to keep it running?


its overheated impeller one word

 

[coolguy147]

Re: 1956 Johnson 10HP Seahorse

for the ignition system do it all in the same hour or two because u might forget something

 

[wbeaton]

Re: 1956 Johnson 10HP Seahorse

ummm sure u can get the motor running but why wouldnt u be able to keep it running?


its overheated impeller one word

It is one word, but that word is not "impeller" it's "coils".

Replace the plugs wires while you are at it. They need to be solid core wires. Copper or steel. Of course, you still need to replace the impeller and the o-ring that sits on top of the driveshaft. JBJ, is an expert on these motors. follow his advice.

I use synthetic oil at 24:1. I use Amsoil HPI since that's what readily available to me. I also picked up some Pennzoil synthetic at Walmart the last time I was in the US. Its more expensive, but worth it.