1978 35hp Johnson Seahorse... Dead?

Hey there guys,

I was hoping someone could give me a few ideas. My motor turns over, has fire at the plugs, the primer bulb stays firm after a pump or two, but the engine just won't wen try to run. It just turns over.

The back story is this... I just bought my boat a month ago and have completely restored it. The last thing I did was get new fuel and try to start the motor. It ran for about 5 seconds the first time I tried starting it, then it did nothing the second time I tried to start. After a lot of head scratching I found a blown inline fuse near the solenoid. So I traced my wires and found that one wire had come lose from the ignition switch and touched another post causing the short and a blown fuse. After replacing the fuse I haven't had any luck starting this engine. I even tried taking the switch out of the circuit and hot wiring the boat. That didn't work either and got me zapped a couple times, lol.

So I've ordered a new switch. It's a 6 pole, 3 position switch. The wires I have seem to be the two magneto wires, the hot positive wire, the solenoid wire, and an electric choke wire.

What else can I try? Am missing something obvious here?

Thanks!

There is a start circuit on your switch and a run circuit (pole) If you aren't getting fire to your run pole when it is turning over (cranking) it won't ever start. You need to get a 12V test light and make sure that you have your switch connected correctly to start with.
I saw where you said you had spark at the plugs. Have someone crank the engine and mix some fuel/oil (proper ratio) in a spray bottle. Mist this in the carb while holding the throttle wide open (motor on muffs or in a barrel) if it fires you have a fuel delivery issue, not electrical.

[url=https://www.tinboats.net/forum/viewtopic.php?p=324931#p324931 said:

MMAtyson » Mon Aug 05, 2013 11:11 pm[/url]"]

So I've ordered a new switch. It's a 6 pole, 3 position switch. The wires I have seem to be the two magneto wires, the hot positive wire, the solenoid wire, and an electric choke wire.

What else can I try? Am missing something obvious here?

Thanks!

Click to expand...

Pretty sure the color code in 78 would have been:

Black - Ground
Yellow/Red - to Neutral Safety switch then to start circuit
Black/Yellow - stop circuit
Purple/Red - from + side of battery
Purple - + 12 out from key (probably connect to tach/fuel/gauge/temp horn if you have them)
Purple/White - choke

Just make sure that the Black/Yellow has no continuity to ground or it wont start

Thanks for the quick replies!

My new switch should be here Thursday. I'll keep you posted on what happens next.

One other question. When I press the throttle lever forward the mechanism on the right side of the engine seems to get blocked at about half throttle by a bracket that has a spring attached to it. If that makes any sense at all, is that a normal finding or something else to address?

Ok, new switch installed. The switch seems to be working ok. I installed the two magneto wires in the same position as the old switch. The choke works when you press the key in. The solenoid and starter engages when you turn the key to the start position. Still no luck with the engine running.

There is a pole on the back of the switch marked with the letter "I". According to the package, this is the "ignition circuit". The diagram shows this go to the ignition circuit, then to ground. I don't have anything attached to this pole because all the wires are already attached to other poles. I only had 5 out of 6 wires? I'm thinking this is the problem... Yes or no? Is this what you were talking about in your post nccatfisher?

Here is the diagram. Everything has a wire except "I".

[url=https://www.tinboats.net/forum/viewtopic.php?p=325289#p325289 said:

MMAtyson » Thu Aug 08, 2013 1:31 pm[/url]"]

Here is the diagram. Everything has a wire except "I".

Click to expand...

You should have a purple wire that goes to that terminal

The other 5 as follows":
Purple/Red should go to "B" this is your hot 12 volts
Black should go to "M" on the bottom of your diagram - it's your ground
Yellow/Red - should go to "S" as it comes from your Neutral Safety Switch
Black/Yellow - should go to your "M" on side of diagram as it is your stop circuit
Purple/White - should go to "C" as it is your choke wire

[url=https://www.tinboats.net/forum/viewtopic.php?p=325282#p325282 said:

MMAtyson » Today, 13:38[/url]"]Ok, new switch installed. The switch seems to be working ok. I installed the two magneto wires in the same position as the old switch. The choke works when you press the key in. The solenoid and starter engages when you turn the key to the start position. Still no luck with the engine running.

There is a pole on the back of the switch marked with the letter "I". According to the package, this is the "ignition circuit". The diagram shows this go to the ignition circuit, then to ground. I don't have anything attached to this pole because all the wires are already attached to other poles. I only had 5 out of 6 wires? I'm thinking this is the problem... Yes or no? Is this what you were talking about in your post nccatfisher?

Click to expand...

Yes.

Well... Yaaaay and crap! I don't have a wire left over to attach to that pole. I did alligator clip the stern light to the "I" post and found that it is hot when the key is in the on position.

I also tried the fuel in a spray bottle trick. The engine will run as long as I keep misting into the carb.

So is it an ignition circuit problem, a fuel delivery problem, or both?

[url=https://www.tinboats.net/forum/viewtopic.php?p=325308#p325308 said:

MMAtyson » Thu Aug 08, 2013 4:33 pm[/url]"]Well... Yaaaay and crap! I don't have a wire left over to attach to that pole. I did alligator clip the stern light to the "I" post and found that it is hot when the key is in the on position.

I also tried the fuel in a spray bottle trick. The engine will run as long as I keep misting into the carb.

So is it an ignition circuit problem, a fuel delivery problem, or both?

Click to expand...

So you're saying there is no wire going to the "I" terminal, but the motor will run? sounds like maybe a tiller model that was converted to electric start?

Definitely a fuel problem by your diagnostic results. Hard to tell on the ignition, you are getting ignition if there is fire, but doesn't rule out that it might have problems.

[url=https://www.tinboats.net/forum/viewtopic.php?p=325312#p325312 said:

MDCrappie » Today, 17:47[/url]"]

[url=https://www.tinboats.net/forum/viewtopic.php?p=325308#p325308 said:

MMAtyson » Thu Aug 08, 2013 4:33 pm[/url]"]Well... Yaaaay and crap! I don't have a wire left over to attach to that pole. I did alligator clip the stern light to the "I" post and found that it is hot when the key is in the on position.

I also tried the fuel in a spray bottle trick. The engine will run as long as I keep misting into the carb.

So is it an ignition circuit problem, a fuel delivery problem, or both?

Click to expand...

So you're saying there is no wire going to the "I" terminal, but the motor will run? sounds like maybe a tiller model that was converted to electric start?

Definitely a fuel problem by your diagnostic results. Hard to tell on the ignition, you are getting ignition if there is fire, but doesn't rule out that it might have problems.

Click to expand...

OK, first you do have a fuel delivery problem if the misting fired the engine. If the bubble will pump up firm and you have no obvious leaks I would give the carb a thorough cleaning. Once you get it running correctly you can go back and see exactly what you have as far as addressing wiring issues.

I noticed small fuel trails down the lower part of the motor tonight. So I started looking at fuel lines. It appears that I may have a leak in the hose the goes into the bottom of the carburetor. When I first pump the primer bulb, if I get really close and listen, there is a hiss coming from that junction where the hose clamp is. After the bulb gets firm, fuel begins to slowly drip from the same area where I hear the hiss. Would something like this cause the engine to be fuel starved and not start?

[url=https://www.tinboats.net/forum/viewtopic.php?p=325353#p325353 said:

Would something like this cause the engine to be fuel starved and not start?

Click to expand...

That wouldn't cause the none starting issue, but it would cause a lean condition once it's running. "Suckin Air".

MDCrappie... Is that quote a "yes"? lol

NCcat, I guess that qualifies as an obvious leak. I don't think I noticed it before because of the water hose running. What really sucks is the location of that hose connection. I don't think I can get to it without removing the carburetor.

[url=https://www.tinboats.net/forum/viewtopic.php?p=325367#p325367 said:

MMAtyson » Thu Aug 08, 2013 11:00 pm[/url]"]NCcat, I guess that qualifies as an obvious leak. I don't think I noticed it before because of the water hose running. What really sucks is the location of that hose connection. I don't think I can get to it without removing the carburetor.

Click to expand...

That hose, leaking under pressure of bulb should not stop the motor from starting.