throttle cable/idle stop problem

[Thumpbass]

I bought a 1979 100hp Johnson back in the spring and am still trying to work all the kinks out. When I got the motor it was set to where it would idle around 1500 rpms on the muffs and around 750 rpms in the water. I was going to lower the idle speed to the recomended 650(max) only to find that the idle stop screw was not (and would not) make contact with the stop...even with the screw all the way in it's still a fair amount away from the stop. So I adjusted the throttle cable to pull the screw back to where it will contact the stop enabling the adjustment to function like it should. But now I can only get the motor up to around 900 rpms (on the muffs) with the idle screw in all the way....I haven't had a chance to go to the lake since I discovered this so I'm not sure what the idle will be in gear in the water but I'm almost positive it;s going to be too low and with no room to raise on the screw. What needs to be done here?

 

[F_R]

Re: throttle cable/idle stop problem

The correct procedure is to adjust the idle speed with it manually up against the stop and the cable disconnected. Then adjust the cable so it just does pull the lever back against the idle stop.

 

[Thumpbass]

Re: throttle cable/idle stop problem

The correct procedure is to adjust the idle speed with it manually up against the stop and the cable disconnected. Then adjust the cable so it just does pull the lever back against the idle stop.

I think that's what I did...may be I wasn't clear or just ignorant8) but anyway...I didn't physically disconect the throttle cable casing guide/trunion assembly from the throttle lever but I took the trunion assembly out of the airsilencer base (where the trunion is held in place) and manually pushed the throttle lever back against the stop, adjusted the trunion to where it would fit back down into the air silencer base with the screw still against the stop...with that being the case I could not set the idle any higher than 900 rpms on the muffs with the idle adjustment screw which I'm thinking it will need to be significantly higher to achieve the 650 in the water.

Just for reference, my original Johnson manual says "if the idle stop screw will not go against the stop, turn throttle adjusting nut until the stop screw contacts with light pressure"[/i]

Any thoughts? thanks for the info

 

[Silvertip]

Re: throttle cable/idle stop problem

This all falls into the link&sync process. If the linkages are not adjusted to spec, all the twiddling with the idle screw and cable length adjustments leads to frustration. Get a manual and do it right. Idle mixture and idle speed are the last steps in t he process. Not the first.

 

[Thumpbass]

Re: throttle cable/idle stop problem

This all falls into the link&sync process. If the linkages are not adjusted to spec, all the twiddling with the idle screw and cable length adjustments leads to frustration. Get a manual and do it right. Idle mixture and idle speed are the last steps in t he process. Not the first.

I have the manual and have synchronized the throttle valves, adjusted the throttle pick up point, adjusted the throttle cable (as stated), and adjusted the choke linkage. I have stopped there mainly because I do not own a timing light and the next step is synchronizing the throttle and timer linkage. I guess this could be where my problem is...according to the manual I should raise the warm up lever until the timing reads 4* BTDC and then adjust the cam yoke to where the top scribe alighns with the roller. May be my idle timing is off.