Now What

[lambertfam]

With the help from you guys (thanks you!!) I have been trying to get my 1967 Johnson 20HP going again (sat for 16 years) but have run into a wall. I've replace the fuel tank, the fuel lines (include the lines from and to the fuel pump and carburator), replace the points, condensers, coils, sparkplug wire, sparkplugs, rebuilt the carburator, and changed the lower unit oil. I tried it again over the weekend and it still does not want to idle and still feels like it doesn't go fast enough.

What else can I do? Compression is good, spark is good, fuel seems good and carb should be clean. All the gaps have been set according to the service manual. Could this be a timing problem? Or carb adjustment problem? Has anyone timed this motor before that could help me out? Are the throttle and choke butterflies suppose to be at the same angle? When I pull the choke, the throttle butterfly barely moves, is that right? Maybe I have some linkage that isn't quite right.

 

[fireman57]

Re: Now What

Sounds like you are on the right track. Go to your local library if you don't have a manual for this engine and grab theirs. There will be a link and sync procedure that you must follow to the letter. This gets everything set to open, close, slide, and rotate at the proper time. It is not hard to do but you must do it exactly as it says and don't skip any steps.

 

[tashasdaddy]

Re: Now What

choke and throttle butterflies are totally independant.

 

[lambertfam]

Re: Now What

I do have a service manual so I guess I'll start there. From what I have read so far, I need to get the throttle arm in the carb to move when the cam follower is between 2 lines on the cam. But, I have loosened the bolts and it doesn't adjust far enough. Should I just bent the rod that the cam follower is attached to so that I can get it set right?

With it not idling slow, what else could that be? Or do I really need to try and get it timed first?

 

[fireman57]

Re: Now What

Once again, the link and sync procedure should take care of this for you. If it doesn't then you will know whether or not to start bending things. Good luck and let us know what happened.

 

[F_R]

Re: Now What

So, what is the problem with the throttle butterfly, that you say you can't get it to open at the mark? Is it opening late? If so, that will affect other things, but not slow idle. It is supposed to be completely closed at slow idle. You could take all the linkage off and toss it and it would still idle because it would be closed as it should.

Is the roller there, and not worn out? You shouldn't have to start bending things.

The throttle is indeed supposed to kick open a little bit when you pull the choke knob. But not very far. Your description sounds like it is normal.

There is nothing to "time". Forget that.

How fast is "not fast enough"? Is it a real dog or are you expecting too much? If it is a real dog, have you checked to make sure it is running on both cylinders? That is the #1 most often reason for being like a dog. Running on one cylinder can be ignition, low compression on one cylinder, ignition, a damaged piston, ignition, a broken reed, ignition, a ruptured fuel pump diaphragm, ignition, spark plug, ignition, water getting into the cylinder, ignition, crankcase seals, ignition, whatever. But not the carburetor. Did I mention ignition? How about a spark plug wire arcing through where it is clamped to the plate?

 

[lambertfam]

Re: Now What

According to the manual the throttle arm and butterfly are suppose to start moving when the roller is between 2 marks on the cam. The way it is now, it starts moving way before that. What would that affect?

The roller is there and seems ok. There are some indentations but nothing that makes me think I need to replace it.

From what you said it the choke is probably working fine.

By "time" I only meant to get the cam follower between the 2 marks on the cam.

Maybe my best bet is to get one of those tachs that you put on the spark plug wires so I can compare the RPM's to what it is suppose to be rated at because for now I'm only basing this off from what I remeber it being like 16 years ago. And that's along tie ago.

How would you check an arcing spark plug wire? I replaced all of the ignition parts including the spark plug wire last weekend, so I hope its not ignition or I didn't do it right. How would I check to see if one cylinder isn't working? I'm happy to spend the money to get it working if I can some how narrow it done to one part, but I don't know how much more I can replace and not get it running right?

What are you thoughts?

 

[fireman57]

Re: Now What

You can get a cheap spark tester at autozoners for about ten bucks. It is easy to use. You may have dropped a coil as fr said.

 

[lambertfam]

Re: Now What

the coils were also replaced with the rest of the ignition components.

 

[crash Jason]

Re: Now What

Make sure you've got good spark on both cylinders. my 1964 28hp sounded like it was running ok but was real doggy. turns out one of the kill switch wires was worn and it was grounding one set of points so it was running on one cylinder. didn't find the problem till I started it in the dark and saw it sparking by the cut out switch.

 

[lambertfam]

Re: Now What

Now that you mention that about the kill switch, one of my wires is also frayed. I just wrapped some tape around it but maybe that's not enough. Can I replace it with regular stranded wire? Or do I need to purchase the part through a dealer?

I went back through all of the notes you guys have helped me with and checked the spark (looked good on both) and checked compression (125 on on and 130 on the other) and tried flipping some of the connecting pieces from the carb to the cam follower but nothing has helped. I still can't the the throttle arm to first move when the cam follower is in between the 2 lines.

Does anyone else have any ideas? Please. I am almost to the point of giving up but really don't want to. Can I check anything else?

 

[jbjennings]

Re: Now What

Lambertfam,
Your compression is fine with 125 and 130. don't worry about that part. You definitely should be able to get that butterfly to barely start opening when the cam passes the marks. I'm not saying to start bending stuff, but I did have one that the little arm that holds the cam was bent and it ran like crap. I took that carb all apart several times and cleaned it and was at my wits end when I finally tried to bend the arm as a last resort so that the butterfly would open at the right time it ran perfect. This may not be your problem and I have no idea how the previous owner bent it like that. I'm just saying that it should start to open when it passes the marks and you might CHECK to see if a bent part might be the problem.
Also, just because that spark looks good doesn't mean it's not your problem.
Now that I think about it, since you've got it running, take it out on the lake and try the old pull one plug wire routine and see if pulling a plug wire has an effect. If it will run with the top wire off but won't run with the bottom wire off, or vice/versa, then you know you don't have good spark to one cylinder. I've replaced coils and still didn't have good spark lots of times--from bad points, arcing wires, bad corrosion on the ends of the wires where they met the plug or met the coil (the coil ends in particular), and even bad condensers.
You might also try running it in a barrel with the cowl at night so you can more easily spot any arcing.
I hope you find the problem--with nice compression like that, it should run great!
JBJ

 

[lambertfam]

Re: Now What

Thanks for your help. I will try pulling the wires off the plugs and see what happens. I should be able to do that in a bucket, right? Or do I need to be in gear and at full speed? As long as I only touch the insulation on the wire I won't get shocked, right?

I like your suggestion of trying it at night. I'll have to try that to. If I see spark or anything glowing then I know that the current is jumping and the spark on that wire is bad, right?

As for the bending the arms it actually looks like at some point the arm that holds the cam follower snapped off at the bend and instead of getting a new one someone just through a glob of weld on it and called it good. Who knows if it's in the right spot. The only thing is though I know my dad didn't do it and it used to run fine when we used it 16 years ago. Either way maybe I should just buy a new one so I know it's right. I wonder if I can still find that part.

Thanks for the continue suggestions and support, I would love to get this thing running and without you guys I think I would have given up long ago.

 

[lambertfam]

Re: Now What

Per jbjennings suggestion I tried pulling the spark plug wires off and when I pulled the top one the motor kept running. But when I pulled the bottom one, the motor died. This means the top cylinder isn't working, right? When I pulled the top wire off and it kept running I tried to put the wire back on the spark plug and as soon as I got the wire to about 1" of the plug I had a blue spark jump across the two. Does this mean my spark is good and the top cylinder isn't running for some other reason, or is it still a problem with the ignition for that cylinder? What should I try next?

Mike

 

[tx1961whaler]

Re: Now What

Switch the spark plugs, just to make sure that you don't have a bad one.

 

[lambertfam]

Re: Now What

Ok, thanks. I'll try that tonight hopefully and report back. Any other ideas if this proves to not be the problem? Any other troubleshooting I can do while I'm working on it?

Mike

 

[jbjennings]

Re: Now What

You definitely lost your top cylinder. Usually it's spark. The spark plug change sounds logical and I'd surely try it. I'm suprised it would jump such a large gap but still, you may have intermittent spark. It's unlikely, but possible, that your spark plug wire could have a break in the conductor inside the insulation and when you moved the wire, it made the circuit and sent voltage to the plug. You might try to hook up a cheapo meter to it and run Ohm it out while flexing the wire to see if it has a break inside the insulation. You've got to check it all step by step to find the culprit.
Hopefully, it's just a spark plug.
Ignition problems can be REALLY annoying to figure out.
Good luck,
JBJ

 

[lambertfam]

Re: Now What

Well I flipped the spark plugs and tried starting and couldn't get it started. I then flipped them back and was able to start it after a few pulls. So, I'm reasoning that if the top sparkplug was bad, when i flipped it then it would cause the bottom cylinder to not work also. But, if the good plug was put in the topcylinder and it still didn't work then there gotta be something else going on in the top cylinder, right? But, it would also show that the spark plug that was in the top is probably also bad, right? Or am I way off here? Im thinking I should stop and pick up new plugs since it is a relatively cheap check. But what else could this be? When I get more time I'll try and take the top flywheel apart and do some more checks with an ohm meter.

Any other ideas or other tests I can do?

Thanks, Mike

 

[jbjennings]

Re: Now What

Lambertfam,
I think we've got this problem almost certainly narrowed to no spark on the top cylinder.
I reread the thread and you say you've replaced the coils, points, condensers, and plug wires. Is that correct?
IF so, then I believe you've got a bad connection somewhere in the circuit.
Here are some places I've found to be troublesome:

• the spark plug connector to wire connection inside the spark plug boot.
• the spark plug wire connection to the coil.
• the points for the top cylinder could have slipped and now are not gapped properly.
• the coil is not pushed back flush with the mounting boss and is rubbing the flywheel for the top cylinder.
• You bought a sierra coil and it's bad right out of the bag. Not that sierra makes bad stuff, but I've had one do that which I bought from them.

Now if you haven't pulled the flywheel and replaced the coils and such, therein lies your problem.
Post back when you find it.....I'm ready for you to whip that thing so you can post some running pics!

Later,
JBJ

 

[lambertfam]

Re: Now What

Jbjennings, thanks a lot for the suggestions.

I have replaced all the ignition components so looks like I get to try and find the bad connection. I was going to take the flywheel off but I wasn't sure how to test some of the problem areas. With the spark plug wire installed in the coil, is there a way I can use an ohm meter to make sure it is connected correctly? Can I put one lead on the coil in the sparkplug boot and the other on one of the leads coming off the coil? Or will that not show a complete circuit? I will double check the point gap and make sure the coils are flush to the machined diameter while I'm in there.

You mentioned that sometimes coils come in bad. I still have the old ones, I think. Would it pay to put the old ones back on? They didn't seem bad, no cracks or leakage.

Is there a way to check to see if a coil is bad with an ohm meter or something?

I wish it would run too. I still think I have a problem with my throttle arm and cam roller position but this seems like the bigger problem for now.

Thanks again for all your suggestions.

Mike