It's me again...1972 johnson 20hp not running well

[jwilkey84]

Here is what I have done/know:
-fuel is good, new gas lines, tank is clean, primerbulb retains pressure, relief valve is open
-new impeller
-carb kit installed, new needle valve that is turned 1 and 1/2 turns out
-all new wiring from key switch to battery and solenoids.
-spark was good last summer when I checked it last
-I acquired this motor last summer and have not got it to run right yet, but I am determined. Usually it will start and run anywhere from 3-20 seconds before dying. I think the only thing I have not done is to take off the flywheel and take a look at the points and I have not replaced the fuel pump. The previous owner said the reason he quit using it was because the lower unit was bad, but I think he is wrong because I realized that the shear pin was broke, so I replaced it and I think that was his problem. He never said anything about it not running well, so I am trying to figure out what could have went wrong in about 2 years of sitting. Please don't recommend cleaning the carbs, because beleive me I have put a kit in and it is as clean as a new one. My question is: Do you think it could be the points or possibly the fuel pump? Thanks for the help, hopefully together we are closer to having another outboard motor running like it should.

 

[tashasdaddy]

Re: It's me again...1972 johnson 20hp not running well

have you tried, squeezing primer bulb to keep it running. also the bowl would not run out of gas in just 20 - 30 seconds. so i don't think it is the fuel pump. could be link and sinc. or a coil getting hot. i think you need to check under the flywheel.

 

[jwilkey84]

Re: It's me again...1972 johnson 20hp not running well

what exactly would I be looking for under the flywheel? I have looked at some pictures and diagrams/instructions for installing new points, but I have never actually done it. Also my manual is a seloc, which I think sucks and I don't think it tells me how to do a link n' sync. Also, how would I know it a coil is getting hot?

 

[tashasdaddy]

Re: It's me again...1972 johnson 20hp not running well

if the are cracked or discolored, look like they've been heated, replace.

 

[jwilkey84]

Re: It's me again...1972 johnson 20hp not running well

I figured that, but other than the obvious signs is there a way to check?

 

[tashasdaddy]

Re: It's me again...1972 johnson 20hp not running well

see what you come up with. i will be away at the boat show tomorrow.

 

[F_R]

Re: It's me again...1972 johnson 20hp not running well

dirty, oily, out of adjustment points. Bad coils (cracked or hole burned through the bottom). Bad spark plug wire arcing through where it is clamped to the armature plate. These are some of the things to look for.

You told me not to suggest the carb, so I won't. But I can wonder whether you inspected the high speed jet orfice. But I won't ask.

 

[Solittle]

Re: It's me again...1972 johnson 20hp not running well

In addition to checking under the flywheel what do the plugs look like just after it dies?

You could also take a squeeze bottle with pre mix and squirt some directly into the carb when it does fire. That will aid in pointing to fuel or ignition as the place to look.

Like F_R I won't ask if you soaked the carb overnight and blew out all the passages with high pressure compressed air. Nahhhh---

 

[jwilkey84]

Re: It's me again...1972 johnson 20hp not running well

Since you wont directly ask what I did to the carb, I will just tell you. LOL I totally disassembled cleaned, cleaned, and cleaned some more. Did not forget the preset jet in the bottom of the bowl. took out, cleaned, and replaced all of those little cap looking things. Replaced needle valve, brand new. Set float, although it wasnt that far off to begin with. And of course installed the carb kit parts. I will try the shooting premix into the carb again before I pull the flywheel, and I think I might also unhook the fuel line on the far side of the fuel pump and see how far it shoots gas as the motor cranks. How far should I expect?

 

[jbjennings]

Re: It's me again...1972 johnson 20hp not running well

Jwilkey,
If you spray some gas into the carb and it cranks up and runs just long enough for that fuel to be used up and then dies, then it's a fuel prob. Is that what it does? If not, then does it run good for 20 seconds or so as far as idleing smooth and then starts to roughen up and die? Then it could be a float adjustment problem. What kind of float does it have--plastic or cork? IIf cork, change it with plastic, although yours is a new enough model that I don't thing they used cork then. Also, does it have a little passage that runs up the side of the bottom of the bowl on the carb. ? If you do, then did you make sure it was blown out good? (I forgot to clean that passage once, and it ate my lunch while I tried to figure out what was wrong). Just because the coils look good, doesn't mean they are good. If one's bad, then that could be a problem. Your points could be burnt, and you can't tell unless you remove them and check the contacts. Sand 'em off smooth if you need to. How about your intake manifold seals and carb mount seals...Do they leak any air? THat's a real booger to catc sometimes for me....While it's running you can spray a little fuel around the intake manifold and see if it makes a difference if it'll run long enough. I'm just wondering if your float may be off and not letting enough fuel in to fill up the bowl. I don't think it's your fuel pump because you could squeeze the primer bulb and get enough fuel in the carb bowl to get it to run longer than what you say it runs--3-20 seconds.
JBJ

 

[F_R]

Re: It's me again...1972 johnson 20hp not running well

With the testimony concerning what has been done to the carb, I am going with the ignition. But I'm not going to ask what the compression is, or whether it is getting water into the cylinders.

 

[jwilkey84]

Re: It's me again...1972 johnson 20hp not running well

the compression was like 120 in each cylinder, as for water in the cylinders I have no clue. How do I tell?

 

[F_R]

Re: It's me again...1972 johnson 20hp not running well

After it runs those 20 seconds, take the plugs out and look for water droplets on them. Shake them to see if you can shake any water droplet out of them. Gas/oil don't count. It is easy to tell the difference, water beads up into droplets.

 

[jwilkey84]

Re: It's me again...1972 johnson 20hp not running well

will do, thanks!

 

[wilde1j]

Re: It's me again...1972 johnson 20hp not running well

The new needle valve (I assume it's a low speed needle) 1 1/2 turns out ... That's just a starting point which needs adjusting after the motor runs. If it has good spark and the timing is correct, look to a fuel problem.

 

[jwilkey84]

Re: It's me again...1972 johnson 20hp not running well

Good news!! I took off the flywheel this morning and everything looked really clean and practically new underneath there. The only thing I did was take some emery cloth and work over the points a little. I put everything back together and also checked the fuel pump, it was working goood. I also checked the spark again, just for fun. I installed a new fuel connecter on the fuel line. I turned the key and it actually ran!! It probably ran for at least a minute before it died. Then I turned the key and messed with the throttle a little and it started again and I was able to keep it running for at least 5 minutes. It seems to run, but it still has an occasional cough.
With the motor running in neutral, I don't think it is idling down as far as it should befoer it dies. I noticed that when I use the tiller throttle the motor will actually start speeding up before the linkage at the carb ever moves. It seems like the motor speeds up as a result of the armature plate moving, not the carb operating. Maybe this is normal, I don't know, I am still learning. It really speeds up when the marks on the cam on the bottom of the armature plate start to line up with the cam follower. Is this where the linc n sync procedure comes into play? Maybe it is just the tiller throttle mechanism out of adjustment?
One more thing, when I shut the motor off and put it away, I took the spark plugs out to take a look at them. They were both clean previous to starting the motor. After runnning for a few minutes the top one came out black and oily, but the bottom one came out black and dry. Is this cause for concern?

 

[wilde1j]

Re: It's me again...1972 johnson 20hp not running well

The "cleaned up" points should be replaced. The new ones are typically plated to prevent pitting, and once the are cleaned up, they should be replaced. You didn't say if you tried adjusting the low speed needle or not. I assume not. Try that too.

 

[jwilkey84]

Re: It's me again...1972 johnson 20hp not running well

when you say "new" you mean brand new, not NOS, right?

 

[wilde1j]

Re: It's me again...1972 johnson 20hp not running well

Correct!

 

[K.B]

Re: It's me again...1972 johnson 20hp not running well

From what I read you said new wires to the ignition switch but did you put new plug wires in also? Said one plug was black and wet, other was black and dry. One's firing and one ain't. Still need to lean your slow speeed needle sounds like from saying it ran longer. Try another half turn in and see what you get.