1998 Johnson J115ELECM idle adjustment help!

[KTEC]

Good evening. Need help adjusting the idle on this engine.

A little background - I bought this engine last year and it would not run. Did a bunch of work last year but never got it to run properly - Just about every gasket exposed to fuel was cracked and falling apart. Work completed last year:

1. Rebuild the carburetors (found many degraded gaskets)
2. Replaced the float chambers (bowls) due to warpage
3. Replaced the vapor separator needle & seat and gasket
4. Rebuilt the vapor pump (bad gaskets)
5. Replaced the VRO pump to fuel pump only and now pre-mix 50:1.
6. Compression ~ 130 - 140 psi on all cylinders

Would run but not good, spitting and sputtering off idle. Ran out of time for the year so winterized it.

Last weekend I finally got around to working on this again:

1. Removed the manifolds and replacing the manifold to block gaskets (found them deteriorated and cracked)
2. Replaced the manifold to carb gaskets (found them flat and not sealing).
3. Checked to verify all four butterflies were closed and then synchronized the carbs to the timing but did not check the timing (I do not have the tester called out in the manual).
4. Adjusted the idle mixture screws to 4-1/2 turns out.

Started it up, seemed to run good and is very responsive now off idle. However, idle is high, around 1200 - 1400 rpm.
How is the idle set or adjusted on this engine? I do not see any throttle screws and the throttle plates are fully closed anyways. I confirmed the throttle cable is not pushing the linkage open.

The manual does not discuss setting the idle only provides a spec. Any ideas? Any help is appreciated.

 

[Chris1956]

My Johnnyrude Service manual covers your motor. The initial idle mixture setting is spec'd at 5-3/4 turns open.

Make sure the motor warms up and the QuickStart system disconnects as that will increase idle RPM to 1200 or so.

 

[KTEC]

My Johnnyrude Service manual covers your motor. The initial idle mixture setting is spec'd at 5-3/4 turns open.

Make sure the motor warms up and the QuickStart system disconnects as that will increase idle RPM to 1200 or so.

Is a timing light the only way to confirm the QuickStart system disconnects? My understanding is this system advances timing by about 10 degrees until warm and then should drop back to normal timing setpoint of 4 degrees ATDC.

 

[Chris1956]

You see/hear the Quickstart system stop. It can take some time. If you need the timing settings for your motor please advise.

 

[KTEC]

You see/hear the Quickstart system stop. It can take some time. If you need the timing settings for your motor please advise.

Chris, thanks for the information. I ran the engine for about 20 minutes with warm water coming out of the engine but did not hear any change and the rpms did not drop. I can hook up a timing light to confirm the change. I believe the initial timing is 4 degress ATDC and full throttle is 20 degrees BTDC.

 

[Chris1956]

Your timing specs are correct. I believe Quickstart advances the idle timing.

If you disconnect the 2 wire sensor on the cylinder head, Quickstart should be disabled.