1985 Johnson 115 - Help adjusting idle

[Bama John]

New to me 1985 Johnson 115 wants to die when going in gear. From what I read this could be caused by a low idle speed and I hope to get back to the lake Friday to see if I can adjust the idle if that appears to be the problem. I have searched and read a lot on the subject but I am far from sure I understand so your help is much appreciated.

Do I adjust the idle using the threaded rod at the red arrow? If so which direction to increase idle?
Do I need to give slack at the Green arrow and then snug it down once the idle is correct?
Or straighten me out altogether...

https://photos.app.goo.gl/ALdoyGFijC1VLmvZ2 Link to Photo of Motor - I tried to embed the image but this is my first post and I could not make the embed from another location option work...

 

[flyingscott]

First thing to do is a compression and spark test.

 

[ondarvr]

Yes to the green arrow screw, but that's only if a low idle setting is the issue.

 

[spybot]

The green arrow adjusts your idle the top red one adjusts your timing.
Im sure others with more knowledge than me will help out. Mr Joe Reeves has this documented on here some where.
But if the idle is causing this ????? The green arrow is the one to adjust

 

[interalian]

Agree with Flyingscott - check compression. And do not adjust the rod at the red arrow - that sets your maximum timing advance and you could wreck your engine. Unless the motor has been apart or a new timer base installed, no reason to ever touch that.

 

[Bama John]

I checked compression and spark today. Getting spark on all 4 but compression may not be so good. I did not have the throttle open during my compression tests but it seems I should have. Do you have to jump out the starter or such to crank over with the throttle advanced? This motor has the fast idle lever on the control box, I can't put it in neutral and open the throttle.

Port Starboard
75 -- 90
90 -- 90

Thanks again for the help.

 

[racerone]

The throttle position simply does NOT matter on a 2 stroke engine like yours.----Either your gauge is faulty or the motor needs internal work !!----Remove cylinder head that shows 75 psi and have a look in there.