1992 OMC 9.9/15 HP Idle Adjustment

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wmk0002
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Location: Cullman, Alabama

1992 OMC 9.9/15 HP Idle Adjustment

Post by wmk0002 » 03 Aug 2016, 11:02

I recently picked up a nice little 1992 Johnson 9.9 hp with a 15 hp carb. I have a couple of the same motors from the early 80's with the gear/teeth throttle control and the side idle adjustment screw but this one has the cable system (which is one specific reason I got this one). I received my factory service manual in the mail yesterday and was reading through it last night. From my interpretation, the manual seem to contradict itself on the idle adjustment. In an early section it states to adjust the forward idle by adjusting the trunnion ball on the cable system, which pops into a space in the lower cowling. However, in a later section relating to the tiller handle, the manual states to use the idle adjustment piece on the end of the tiller handle.

From the little I have toyed with it, I have found that the adjuster on the handle is too fine and has too little range to accomplish this. It seems more like a fine tune adjuster for after you adjust the trunnion ball to get you in the ball park. I've also found that using that adjuster decreases the easy of motion of the twist grip. Should I proceed with adjusting the trunnion ball first to get a low enough idle and then use the tiller handle adjustment as necessary? My only fear here is that I totally get the cable system out of wack and it mess up things like making sure the timing plate opens all the way up when the twist grip is at full throttle.
2016 Alumacraft 1648 NCS - 1992 Johnson 9.9 HP Tiller
http://www.tinboats.net/forum/viewtopic ... 21&t=40764

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