1996 25hp johnson questions

[miller6323]

Hey everyone, I'm new to outboards but build hotrods as a hobby so I'm hoping to pick up on it pretty quickly. I've got alot of questions so please bear with me. My 1996 25hp Johnson was coughing and dying out at idle but would run great at wot so I was trying to do some carb tuning on it yesterday. When it died it backfired and spun what I'm guessing is the timing assembly around. (Under the flywheel) I was able to get it all back in place but it broke the plastic clip for the throttle control rod. I tried to start it after getting everything back in place and now it's acting like things are in a bind. Any thoughts are appreciated.

 

[Michawilden]

If you have a backfire it can break the timing / woodruff key in the crankshaft. If you hav not touched the stator plate ( ignition under the flywheel) than that will probably be good and wil not bind. Flywheel might be spinning on the crank tap now so first check the key. Coughing at low rmp is starving for fuel. could be that the low rpm circuit is clogged or just to lean. Try to back out the mixture screw in front on top of the carb.

 

[miller6323]

If you have a backfire it can break the timing / woodruff key in the crankshaft. If you hav not touched the stator plate ( ignition under the flywheel) than that will probably be good and wil not bind. Flywheel might be spinning on the crank tap now so first check the key. Coughing at low rmp is starving for fuel. could be that the low rpm circuit is clogged or just to lean. Try to back out the mixture screw in front on top of the carb.

So I need to pull the flywheel to inspect everything correct? What's the purpose for the throttle control rod?

 

[Michawilden]

Can you post a picture of what you are talking about? I think you're talking about the rod that is attached to the stator that turns the stator under the flywheel? That is for the timing of the spark.

 

[miller6323]

Can you post a picture of what you are talking about? I think you're talking about the rod that is attached to the stator that turns the stator under the flywheel? That is for the timing of the spark.

In not at home and didn't take a picture last night. It's on the port side of the motor and runs from the carb back to where the fast idle connects. It's got a barrel slide thing with a set screw in it. I'll try and find a picture online.

 

[miller6323]

Can you post a picture of what you are talking about? I think you're talking about the rod that is attached to the stator that turns the stator under the flywheel? That is for the timing of the spark.

Where it broke is the red arrow. It's connects on the other side to the linkage on the top of the carb.

 

[racerone]

If that rod opens carburetor too early the motor will stumble and stall.-----I often see that adjustment wrong.-----It looks wrong when it is correct.

 

[miller6323]

Where it connects on the carb from what I've found online it's supposed to start opening the butterfly between the timing marks and I've got that set right. But on the side you can see in the picture idk where to set the stop and can't find much online.

 

[Michawilden]

There is a cam on your stator which has timing marks, The rod (i think ) should only control the throttle body at 1/2 till full throttle or something. before that it is the cam on the stator. But first check the woodruff key. You can test it by marking the nut and the flywheel.

 

[racerone]

The cam opens the throttle plate at the marks.-----See your manual for the correct adjustment of the stop on that rod !!

 

[miller6323]

I'm the 4th owner of this boat that's pushing 30 years old.The manual is long gone at this point. That's why I'm here.

 

[davidmbv]

eBay has a service manual for your motor currently selling for 25$ free shipping . I picked one up for my 50 year old Johnson few years ago. Lots of valuable info for all kinds of service work.

 

[racerone]

If you take a close look at the operation of the linkages , you will see.-----That rod and that goofy spring holds ignition fully advanced.----When you back off the throttle it hold ignition fully advanced and allows throttle plate to close.----A fuel saving feature.-----Hurry to your local friendly shop and have them adjust it in minutes.

 

[miller6323]

Is it normal for a backfire to spin the timing around jamming it up? I'm talking about what's under the flywheel...it spun around way past where the the thing that has the marks on it is and wedged itself in.

 

[racerone]

Something is / was loose under the flywheel.----Or components were not adjusted properly and flywheel is catching on them.-----Time to pull it and make the needed repairs !!

 

[3rdtimesthecharm]

Get a factory service manual off of eBay.