1964 40hp Johnson won't run

[64pacer]

Ihave a 1964 40 hp Johnson super seahorse that wont run. I have cleaned the carb properly, have spark, fuel pump is working and there is fuel in float bowl of carb, low speed mixture screw is 1.5 turns out. The engine will run on spray gas but does not seem to be drawing fuel through the carb. Yes the high speed and low speed fuel circuits are clean and clear of an obstructions. i tried spraying some carb cleaner below the flywheel to see if i had a bad crank seal but that appears to be good. Any thoughts greatly appreciated.

 

[Beek14]

Re: 1964 40hp Johnson won't run

Could there be any leaks in the lines? Primer bulb ok? How is compression?

 

[64pacer]

Re: 1964 40hp Johnson won't run

all fuel lines are new and so is the primer bulb and fuel line disconnects.

 

[rTagster]

Re: 1964 40hp Johnson won't run

i have a johnson seahorse cd-10 that i seem to be having the exact same issue. i have gotten it to run a few times with some coaxing of carb cleaner, but its not consistent with starting or running. so i'll be watching this thread quite closely.

on mine i do not have a primer bulb, i just have a straight fuel line that goes directly from the pump to the fuel tank, and its just a normal fuel tank, so that could be my problem, but i do have fuel in the fuel line and in the carb cause i can see it.

so im not sure whats causing it not to run.

 

[rTagster]

Re: 1964 40hp Johnson won't run

mine seems to have good compression, i will check it for sure, but i was wondering if the coils were bad would it still ignite from time to time?

 

[alleymize]

Re: 1964 40hp Johnson won't run

I too have the same problem. I have a 40hp johnson 1970. I have rebuilt the fuel pump as well and the carb. I have taken the gas line off at the carb and see a steady stream of gas on turning it over and I took the carb back off and can see the bowl is filled with gas but I am not getting any of the gas up into the cylinders for some reason. It will run as long as I spray starting fluid down the throat of the carb and then goes out. Any help Please!!

 

[rTagster]

Re: 1964 40hp Johnson won't run

Well it seems all of us that are having the problem are the only ones getting on iboats. haha!! Kinda figures, everyone that has a running boat motor is out on the lake catching all kinds of fish and enjoying the summer. While the rest of us poor souls who cant get our boats running stick around iboats hoping for some free advice. haha!!

 

[lindy46]

Re: 1964 40hp Johnson won't run

mine seems to have good compression, i will check it for sure, but i was wondering if the coils were bad would it still ignite from time to time?

Coil(s) could be going bad and firing intermittently, usually after things heat up. You need to get a primer bulb in your fuel line!

 

[lindy46]

Re: 1964 40hp Johnson won't run

I too have the same problem. I have a 40hp johnson 1970. I have rebuilt the fuel pump as well and the carb. I have taken the gas line off at the carb and see a steady stream of gas on turning it over and I took the carb back off and can see the bowl is filled with gas but I am not getting any of the gas up into the cylinders for some reason. It will run as long as I spray starting fluid down the throat of the carb and then goes out. Any help Please!!

Does it run if you keep squeezing the primer bulb?

 

[rTagster]

Re: 1964 40hp Johnson won't run

before i get into the coils and change those out, should i see if it runs with a bulb? my carburetor has gas in it so i would think it would run off of that gas and start to pump once it started to run, i know i have a little gas in the line and carburetor. is it not enough?

 

[rTagster]

Re: 1964 40hp Johnson won't run

Coil(s) could be going bad and firing intermittently, usually after things heat up. You need to get a primer bulb in your fuel line!

do you mean they will fire intermittently when things heat up? or because the motor heated up too hot it ruined the coils which will only allow them to fire intermittently because they are going bad?

 

[glassmaster68]

Re: 1964 40hp Johnson won't run

1st make sure there is good compression.Then make sure you have adequate spark.After you have this,you can rule out your fire,,if your 1964 coils are still on there,get some new ones,points, cond.If your motor runs ok spaying premix in the carb[only use premix ,not starting fluid or carb cleaner,no 2stroke tcw3 in those,thus no lubrication]then your carb isnt getting fuel,or your fuel pump bad,or float/needle valve stuck,,make sure the float isnt hitting the inside of the bowl,i recently had that problem,also check that gasket between bowl and carb body,there is an air hole that is easily restricted if the gasket moves a lil off.

 

[alleymize]

Re: 1964 40hp Johnson won't run

I do have a bulb but no matter how much I squeeze it it never starts. I have pumped and pumped and have never seen gas come into the carb throat. Also does it matter if I have a Johnson motor and evenrude gas tank? I just changed the one end to fit my motor. There is gas in the carb bowl and it does eventually get hard I am guessing that meaning the float is set correct.

 

[lindy46]

Re: 1964 40hp Johnson won't run

I do have a bulb but no matter how much I squeeze it it never starts. I have pumped and pumped and have never seen gas come into the carb throat. Also does it matter if I have a Johnson motor and evenrude gas tank? I just changed the one end to fit my motor. There is gas in the carb bowl and it does eventually get hard I am guessing that meaning the float is set correct.

Tank doesn't matter - they are the same. If the bulb gets hard, then fuel is getting to the carb and the float is working. You probably still have an internal clog somewhere in the carb. Take it apart, soak it in carb cleaner, and blow out all the passages. Make sure to remove the welch plug at the top of the carb and make sure the passages under there are clear.

 

[lindy46]

Re: 1964 40hp Johnson won't run

do you mean they will fire intermittently when things heat up? or because the motor heated up too hot it ruined the coils which will only allow them to fire intermittently because they are going bad?

I've seen coils going bad which run good at first, but when the motor warms up, they start cutting out intermittently. Also, if you have one bad coil, the motor will appear to run good at idle speed, but not at high speed. Those motors will idle pretty good on one cylinder.

 

[alleymize]

Re: 1964 40hp Johnson won't run

ok, looks like I am going to have to take the carb off again and give it another cleaning. Some where something must be stopped up but I don't know where. I did remove the tin plugs and clean under them when I rebuilt the carb and reinstalled them. It did not seem that dirty under them. I will keep you posted and thanks for the help.

 

[rTagster]

Re: 1964 40hp Johnson won't run

so if i can get my motor to run at times is my only issue somewhere in my ignition? kind of sounds like it to me. Because i can get it to run from time to time off of gas and not just the carb cleaner.

 

[Lion hunter]

Re: 1964 40hp Johnson won't run

Tagster: You need a primer bulb.

Tagster and Alleymize: You need to start your own thread. Hard to determine who we're helping when there are several people asking questions on the same thread.

Everyone:

Compression, compression, compression! You must check compression. Without it nothing works. It needs compression for the fuel to be drawn in the cylinder. It needs compression for the fuel to combust properly in the chamber. It needs compression for the burnt fuel to exhaust. It needs compression to start the process all over again. So to make a long story short, they need compression. Once that is verified then move to spark. Hot blue spark that will jump a 7/16" gap on a tester. Then move to fuel.

If you try and troubleshoot out of order you will throw money and parts at it that may not be necessary. Let us know the results and we can go from there and get you on the water.

 

[rTagster]

Re: 1964 40hp Johnson won't run

Tank doesn't matter - they are the same. If the bulb gets hard, then fuel is getting to the carb and the float is working. You probably still have an internal clog somewhere in the carb. Take it apart, soak it in carb cleaner, and blow out all the passages. Make sure to remove the welch plug at the top of the carb and make sure the passages under there are clear.

what is the welch plug at the top of the carb?

I've seen coils going bad which run good at first, but when the motor warms up, they start cutting out intermittently. Also, if you have one bad coil, the motor will appear to run good at idle speed, but not at high speed. Those motors will idle pretty good on one cylinder.

that's gotta be what my problem is. like i've said a few times i can get it to go sometimes, but its once every 20,000 pulls, so consequently i get quite frustrated.

 

[rTagster]

Re: 1964 40hp Johnson won't run

Tagster: You need a primer bulb.

Tagster and Alleymize: You need to start your own thread. Hard to determine who we're helping when there are several people asking questions on the same thread.

Everyone:

Compression, compression, compression! You must check compression. Without it nothing works. It needs compression for the fuel to be drawn in the cylinder. It needs compression for the fuel to combust properly in the chamber. It needs compression for the burnt fuel to exhaust. It needs compression to start the process all over again. So to make a long story short, they need compression. Once that is verified then move to spark. Hot blue spark that will jump a 7/16" gap on a tester. Then move to fuel.

If you try and troubleshoot out of order you will throw money and parts at it that may not be necessary. Let us know the results and we can go from there and get you on the water.

hey thanks for your help. i will check my compression next.

however it seemed like me alleymize were doing good on this thread, people were responding to us, we both have similar questions. Plus i have posted many times on my own thread and have not gotten any help, i finally am getting people to help me out on this thread so im gonna stick with this one.