200 Johnson stalling

[jay's snake]

1996 200 JOHNSON VENOM
Model J200STLEDM
Serial G 03972270

The motor runs and idles great when I first start it up. Then it accelerates smoothly and I can run at any speed and it sounds perfect.
However, when I slow back down to a stop, the engine dies. Then I restart it and it does not want to idle without dying. I try to put it in gear and it dies.
The only way I can keep it running is by priming it by pushing in the key.

I took all the carbs apart and cleaned them. I made sure all the jets and passages were clear and checked the float levels. Actually I did it twice because I found the small fuel lines were deteriorating that connect to the manifold after I cleaned them the first time. The fuel is clean and the bulb is pretty firm when the problem occurs.

Please give me your thoughts. Thanks!

[ChampioNman]

How's shifting?

[jay's snake]

Hey Championman. It shifts into forward and reverse gear fine. Why do you ask?

[ChampioNman]

Was thinking possible shift interrupt switch.

[tdt91]

Possibly some crap in the fuel tank moving around and stopping up the intake? Happened to a buddy of mine, finally after a couple years trying to figure it out they found a bunch of plastic worms in the fuel tank. His Grand daughter would never admit to putting them in there. LOL.

[jay's snake]

Was thinking possible shift interrupt switch.

The shift interrupt switch prevents it from cranking when in gear right? Basically it's the same as a neutral safety switch in a car right?

I have been thinking I have a fuel problem because when it acts up, I can keep it running by using the primer.
I have also thought about adjusting the ignition advance linkage, but I don't want to create more problems. I did notice the roller that activates the throttle is about an 1/8inch away from touching when in neutral. Should that roller be touching when in neutral?

[ChampioNman]

Shift interrupt switch kills spark on one bank. Neutral safety switch prevents starting when in gear. There should be a clear sleeve on the throttle roller, if it is missing that will contribute to your issue.

[jay's snake]

What is the purpose of the shift interrupt switch?
I don't have that clear sleeve (only a black roller). Here are some photos.
Thanks for your help so far Championman!20210228_160256.jpg20210228_160305.jpg20210228_160424.jpg

[tdt91]

Yep, you are missing the roller plastic sleeve. You can get a piece of plastic tubing to fit it snug and be good to go. Champ will probably remember the exact size tubing. Try that first before you do anything else to it.
Throttle roller timing arm adjustment 60* motors (bbcboards.net)

[jay's snake]

Yep, you are missing the roller plastic sleeve. You can get a piece of plastic tubing to fit it snug and be good to go. Champ will probably remember the exact size tubing. Try that first before you do anything else to it.
Throttle roller timing arm adjustment 60* motors (bbcboards.net)

Thanks, I'll try that tubing idea. I just checked and that roller is $20 to order online. What a joke!

[Bassmeister]

The tubing size is 3/8ths ID...inside diameter.

[jay's snake]

The tubing size is 3/8ths ID...inside diameter.

Thanks! but it's not that big. Probably closer to 1/4 inch or 3/16.

[jay's snake]

Ok I have a new problem...

On a few instances, the motor has decided not to start and so I attached my timing light to see if there was a spark and could not get the timing light to show a spark on any cylinder. I then removed the plug, ground it to the cylinder and found it sparking just fine. Tried it again with the timing light and still no flash on the timing light and the engine was still not starting. After messing with it for a while, the timing light then showed a flash and the motor started.

I'm thinking maybe the ignition switch is bad? I have tried wiggling the key while it's running to see if I can make it cut-out, but it did not have an effect.

What else, other that the ignition switch, could cause this problem and how do I test the ignition switch?

Thanks!

[ChampioNman]

Ohm it out.

[jay's snake]

OK, I cannot find anything wrong with the ignition switch. However, I was not able to duplicate the situation where it has no spark at any cylinder.

I ran it on the water again today and once again, it worked perfectly until I slowed down. Once again it would not idle well and it would die when I tried to accelerate. I even disconnected the ground for the shift interrupt switch and it did not make a difference. I checked with a timing light for a spark at each cylinder and it showed all cylinders had a spark. However, I pulled the spark plug leads one at a time with it running and found that the middle cylinder on each side was not contributing. I then swapped the plugs, wires and coils, but could not make the problem move to a different cylinder.

So the timing light shows that those 2 cylinders are firing, but maybe the spark is too weak.

What could be the likely cause since the plugs, coils and wires are not the problem.

I checked the compression and all cylinders are within 5%.

[ChampioNman]

Thanks, I'll try that tubing idea. I just checked and that roller is $20 to order online. What a joke!

Maybe with shipping www.marineengine.com has them for $7.82, 0432869 and the O ring is 0324878 is $4.03.

Try pushing in on the key to give it a shot of fuel when you start to accelerate and see if it helps. Check movement on your timer base also.

[jay's snake]

Maybe with shipping www.marineengine.com has them for $7.82, 0432869 and the O ring is 0324878 is $4.03.

Try pushing in on the key to give it a shot of fuel when you start to accelerate and see if it helps. Check movement on your timer base also.

I put some tubing on that pivot pin and it looks like it should work fine.
The timer base does move, so I think it is OK.

I think the question now is what is the reason that cylinders 3 and 4 don't seem to be working very well? Yesterday I ran the engine in my driveway and pulled off each plug wire one at a time with it running. All except 3 and 4 showed a good drop in RPM, but 3 and 4 didn't seem to be contributing at all. I swapped coils, wires and plugs with no change. Can the powerpack or stator cause an issue with just 2 cylinders?

[ChampioNman]

It could be a pack. Don't think it is a stator or timer base as there are two charge coils on the stator one coil powers cylinder 1,3,5 and the 2,4,6 on the other coil same with the stator.

[ChampioNman]

If you shoot me a PM with your email address, and I'll email you the CDI troubleshooting guide.

[jay's snake]

PM sent.