reduce idle speed johnson 1968 20hp ?

[kawaboy-zx11]

Hi, I have a 1968 Johnson 20hp on a 14ft StarCraft aluminum boat, I would like to be able to troll with the 20hp, I have the mixture screw set to the smoothest idle as listed on this forum. problem is, its too fast for tolling with fishing lures at idle speed. is there any way to slow down the idle speed? Thanks

 

[racerone]

Is there not a stop on the linkage ( below and outside of the cowling ) on this motor ?

 

[kawaboy-zx11]

you may be correct! I totally forgot about that, I think I adjusted it years ago before I cleaned the carb, it idled faster after the carb clean last year. Thanks