1957 18hp johnson seahorse

[iowa84]

Put new coils,impellar,spark plugs and cleaned out carb... It starts out of water (only long enough to start and I turned it off) but soon as I put it in water it doesn't want to start, Would anybody know why? Also the top needle on the carb seems to be stripped and all it does is spins doesn't tighten or loosin... I am so ready to sell this damned thing

 

[Mas]

Re: 1957 18hp johnson seahorse

I'm not certain on the 18, but I think the top needle might screw into a "bushing that might be spinning. If you tighten the "needle valve nut," it should tighten the packing against the bushing and allow you to unscrew the needle. The poor running is probably due to improper carb adjustment.

Mas

 

[Mas]

Re: 1957 18hp johnson seahorse

Yup...just checked it. You carb does have the bushing on the low speed needle. Tighten the nut (the long brass tube the needle goes in) then unscrew the needle.

Mas

 

[iowa84]

Re: 1957 18hp johnson seahorse

ok, I will try that cause that nut was not completly tight. do i turn it 1 1/2 turns? my spark plug wire does have a slit in it, the slit is on the backside of where it meets the spark plug but it still has spark, should i put some electrical tape on it or replace it? <i dont know if that would effect it or not. So if i get that needle adjusted right should that solve my problem of it starting up? I have had it started in the water a couple times but it doesn't want to do it for me anymore.

 

[Mas]

Re: 1957 18hp johnson seahorse

Tighten the nut as you are loosening the needle. Once the needle is able to be unscrewed, snug up the nut a tad. You might want to unscrew the needle all the way out and make sure the needle tip is not damaged. If OK, then lightly seat the needle, then unscrew it 1 1/2 turns for initial adjustment.

Proper needle adjustment (both high & low speed) must be done on the water while the motor is in gear.

Replace the plug wires!...they're cheap. Make sure they are "copper core" from your marine shop and not auto plug wires.

Mas

 

[iowa84]

Re: 1957 18hp johnson seahorse

Ok, I will try that. 1 question when I turn the needle it doesn't move at all, is that because it's not connected to the bushing that you were talking about?

 

[Mas]

Re: 1957 18hp johnson seahorse

If you mean the needle is turning but it is not moving in or out, yes it is the bushing that is spinning or the knob connected to the needle is not tight either. Tighten the knob screw first, then see if it helps. If not, it is likely the bushing the needle is threaded into is spinning.

The bushing is number 92 in the picture:

http://www.marineengine.com/parts/v...ntage-evinrude-johnson/377022/37702200001.htm

Mas

 

[iowa84]

Re: 1957 18hp johnson seahorse

Ok, I will give it a shot tomorrow when I head to the garage I have it in.

 

[iowa84]

Re: 1957 18hp johnson seahorse

Why does it need to be on the water when I adjust the carb? do you mean for start up? Do you think if I replaced the spark plugs and did the needle it will start in the water?

 

[iowa84]

Re: 1957 18hp johnson seahorse

I was thinkin about checkin the head gasket would that have anything to do with it not starting up in the water? Some guy down at the dock said that would have been my problem.....

 

[Mas]

Re: 1957 18hp johnson seahorse

Definitely get her running in a barrel or trash can first. Adjust the low speed 1/8 turns at a time to get it as smooth as possible. Turn it in until it sneezes, then back it out until it's smooth. Allow time for the motor to respond. Back it out another 1/8 to prevent running too lean and burning your motor up. Once the motor is reliable to start and idle etc, it must be finely tuned in gear with a load. The motor responds differently with a load verses just idling in a barrel.

Do you ever check compression and spark health?

Mas

 

[Mas]

Re: 1957 18hp johnson seahorse

Also, check the "top secret" files at the top of the threads for more general trouble shooting info...they're really good!

Mas

 

[iowa84]

Re: 1957 18hp johnson seahorse

So far Im thinkin your a life saver..now lets see if it works and ill call you my hero lol I don't really wanna do any pulling on that motor any time soon because my fingers blistered up from pullin on that motor so much earlier. I have to have this goin for this catfish tourny in a couple months

 

[Mas]

Re: 1957 18hp johnson seahorse

Don't give up on that motor...it's a good one, but gotta tell us the compression numbers.

Mas

 

[kbait]

Re: 1957 18hp johnson seahorse

Are you certain of spark? Use a spark tester, or have someone hold a booted plug 1/4" from powerhead ground (rubber handled pliers work well for this) and give it a yank. Spark needs to jump 1/4" blue bolt in open air to be considered good for .030' under compression. If it's yellow or intermittent. File up the point faces nice and shiny and re-set to .020" if you haven't already. If it's still bad..condensers? And you can quick check compression by just pulling the rope half speed and feeling the whoomp-whoomp (plugs in). If you have blisters, you probably already know it has compression... Should be strong and even for both cylinders. Good luck..
check out the fish.. http://wolfrivercam.com/Shiocton Cam 1.html

 

[iowa84]

Re: 1957 18hp johnson seahorse

positive of spark, new coils on it and sparks plugs gaged to .30...... won't be getting to the boat today have to much to do.. I think the carb gets flooded really easy also.

 

[Mas]

Re: 1957 18hp johnson seahorse

If flooding is at issue, did you check float level during carb rebuild? It should be "parallel" to the bowl mounting face when upside down.

But again, your low speed needle is still out of whack which can cause flooding.

Mas