57 Johnson Javalin runs 30 seconds, RPMS climbing then cuts out

Joined
Aug 10, 2012
Messages
3
Having trouble with my 1957 Johnson Javalin 35 horse motor. Unfortunatly last season the motor sat, and this season when I went to start it up (lower end replacement at season close) it would run on starting fluid and then stop. Pulled apart the carburator and cleaned it up, find the needle sticking in the seat. Float seemed good as well, and when I put it back together, motor started like a champ, no starting fluid needed. Put the boat in the water and it started right up, ran 30 seconds and then stopped. Would not start, even with fluid. 2 days later I pulled out the plugs, they were gummed up some, a little oil, but not too much so cleaned them up. Turned it over and started up. Put the boat into the water (1945 Wolverine Wagemaker runabout) and started up first thing, the RPMs climbed to a very high rate, motor stopped after about 20-30 seconds, maybe less. Wouldn't turn over, with or without choke so tried starting fluid with the same results of running 20 seconds or so, increasing RPMs until it stopped.

Second guessing, I replaced the pressure tank as the first time in the water when it didn't start with fluid I though maybe it was flooded as the top of the gas tank was leaking crazily, around the seal and the primer knob. Swapped tanks and seemed good with pressure (when the bonnet is off you can see the gas flowing freely each press of the primer, running through the fuel filter bulb etc...). Wasn't sure if it was a pressure issue, how much pressure should there be? Old tank always leaked, but when you unscrewed the cover the pressure release was big. Newer tank (vintage, not newly built just new to me) has pressure, but much less.

Not sure if not enough fuel, but didn't explain the high reving RPMs. There are two adjustments, a high speed adjust knob and a low speed. Is it possible the high speed jet is off and it is not jettin in enough fuel?

Also saw a post on another 57 Johnson Javalin and that they were running 25:1 fuel/oil ratio? Is that correct? I was under the assumption it was 50:1? Confirmation and suggestions would be amazing! Love this old boat/motor but getting sad/frustrated I can get it running this year!

Thank you all for any suggestions.
 

HighTrim

Supreme Mariner
Joined
Jun 21, 2007
Messages
10,486
Re: 57 Johnson Javalin runs 30 seconds, RPMS climbing then cuts out

Beautiful motor. I collect the Javelins, love them.

You most definately should be running 24:1 ratio in that motor, 50:1 will destroy it, as will using starting fluid in it. Starting fluid has no lubrication. If you need something, put some premixed fuel/oil in a spray bottle to start. Never use starting fluid in a 2 stroke motor.

You sure do describe the symptoms of a faulty pressure tank. The motor will run on the fuel provided in the bowl, then die off. The increased RPMS is it running lean due to a lack of fuel before it dies. Tank may need a rebuild. ALso ensure there are no leaks in the line, especially at the fittings.
 
Joined
Aug 10, 2012
Messages
3
Re: 57 Johnson Javalin runs 30 seconds, RPMS climbing then cuts out

Thank you for your help, narrowing down the problem is very helpful! I had no idea it would be 24:1 for that motor, I run a johnson 35 horse on my pontoon boat and I have had trouble with too much oil even at 50:1. I will double check that tank, the hose might be the problem as it was an older tank that sat long enought to varnish the fuel and dry out the fuel lines. Replacing the hose will be the first try as the tank assembly on the top is fused at 2/3 of the screws. I cannot get them off unless I drill them off and replace/retap.

Love this boat and motor and truly just want to keep it running. Thanks again for the suggestion, I will try and post results.
 

HighTrim

Supreme Mariner
Joined
Jun 21, 2007
Messages
10,486
Re: 57 Johnson Javalin runs 30 seconds, RPMS climbing then cuts out

The pressure tank line is getting expensive, and harder to find, but still out there. If you want, just use black electrical tape and tape 2 single fuel lines together. Much cheaper if you dont care about the look.

Might be easier to buy a good pressure tank, post a wanted ad at aomci.org in the webvertize.
 
Joined
Aug 10, 2012
Messages
3
Re: 57 Johnson Javalin pressure tank repairs

Re: 57 Johnson Javalin pressure tank repairs

Thank you so much for the help, the motor ran great for the time I pressed the pressure plunger constantly. :) So now the question is where would find a reliable pressure tank in working order? I have two that don't work and would rather not buy a third with the same troubles. Are there any companies that sell replacement parts for the tank? One tank I have is rounded edges and someone painted it, so everytime it leaks it causes the paint to peel as well, but the metal is in good shape, its just the seals and pressure plunger that leak. The second tank is more vintage, a 5 gallon tank with the Sea Horse logo, but again the pressure system is not working. Not sure of anyone who would restore them either? Holding onto the tanks and getting them fixed sounds workable, but finding someone is the question.

Also what is the thoughts on the oil mixture in this 1957 Johnson Javalin? The synthetic oil that is ashless and smokes less is available, should it be used in these older motors? I run it on my 1994 Johnson pontoon boat with great results, but have stuck to traditional oil mix for this motor. Now that I know it should be running 24:1 I imagine it will be smoking even more than it was before.

Thanks again, all your help was a great way to narrow down the problems. Now just to fix my pressure tank!
 

kfa4303

Banned
Joined
Sep 17, 2010
Messages
6,094
Re: 57 Johnson Javalin pressure tank repairs

Re: 57 Johnson Javalin pressure tank repairs

Hi Javelin. Check ebay and/or place a WTB add on aomci.org for a good used pressure tank. There are also rebuild kits available for the tank as well. 24:1 is the mix you want to use (5.5 fl. oz. of TCW-3 outboard 2-stroke oil to 1 US gallon of 87 octane) along with Champion J4C, or J6C plugs gapped to .030". These links may help too.

http://www.marineengine.com/parts/v...ntage-evinrude-johnson/377025/37702500001.htm

http://www.duckworksmagazine.com/04/s/columns/max/24/index.cfm
 

nwcove

Admiral
Joined
May 16, 2011
Messages
6,293
Re: 57 Johnson Javalin runs 30 seconds, RPMS climbing then cuts out

The pressure tank line is getting expensive, and harder to find, but still out there. If you want, just use black electrical tape and tape 2 single fuel lines together. Much cheaper if you dont care about the look.

Might be easier to buy a good pressure tank, post a wanted ad at aomci.org in the webvertize.

heres an option to tame the fuel lines if you dont want to buy the expensive oe type dual lines, or dont want to deal with tape coming off. just be careful not to compress the lines to much. ( also works great for keeping plugs wires neat,tidy and separated under the cowl !).....sorry for the pic quality, but you can see the deal.....and that is 1/2" air line, not plug wire.
DSCF1745.jpgDSCF1746.jpg
 

lindy46

Captain
Joined
Nov 27, 2008
Messages
3,886
Re: 57 Johnson Javalin runs 30 seconds, RPMS climbing then cuts out

Laings Outboard has the tank rebuild kits
 
Top