Something amiss on 70 Evinrude high idle??

[joetheis]

Got a 1991 Evinrude on a Grumman fishing boat.
Runs good, but when I got it in the water my idle was 1500 RPM.
I just got a shop manual and a parts manual for it last week from Ebay, so it was reading and plan of attack time until I could get to it, (it's 220 miles away from me at Clayton N.Y).
I figured I'd check all the alignment marks up, check the idle mixtures, even them out, turn the idle screw a turn or 2 and go play!
What I found was the engine timing marks are all golden, but the high speed cable was all but 3 turns turned out, as well as the idle speed screw turned all the way in????????????
The cam wasn't hitting the idle speed screw until I used up the last 3 turns.
The mixture screws were all even- 1 1/12 out
Someone had the carbs off, as they were marked.
The cams on the carbs although close were a tiny bit different.
Also you could see rust marks where the screw had been before on those cams. The screw wasn't in that same location?????????
I got the idle to 900 by taking the last 3 turns out of the cable and went to go play.
(I figured it's running, time is getting short, I'll attack it when I hauled it home for the winter).
I THINK the cams on the carbs are the problem, I THINK if I sync the carbs up (I use the drill bit in the throttle blades method like I do on my BMW dual carb bike- Turn the throttle and lock it to a drill bit size-the other ones should open the same size bit).
Then perhaps take the cable off and back the idle speed screw down and set the linkages so it idles @ 700 er so, and then adjust the idle speed screw, and finally the cable.
At least that's my plan...
Thoughts?
Ideas?
Joe

 

[Bob_VT]

MOST <<<<< of the time the high idle is the cable adjustment coming into the front of the motor. I would start there.

 

[joetheis]

After the coffee kicked in, I noticed the lever wasn't hitting the idle screw, ( that was zipped all the way in).
Then I noticed there was only 3 turns left on the cable at the adjustment.
That was my first adjustment, (well, attempt to get it down)
(I WAS hoping there was a cable adjustment at the controls, but looking in the shop manual, nope)
I was able to get the lever to hit the idle screw, (still zipped all the way in), by taking ALL the adjustment out of the cable, (this left me with a idle of 900 RPM).
So, ALL of the cable adjustment is used up, as well as ALL of the idle screw adjustment, before I can even get started.
This is leading me to believe that when the carbs were done or????, the linkage cams on those carbs and the arm on the lever cam when all three of them are controlled are amiss, (remember the rust the rust marks that didn't make sense on the carb cams). (the pic in the shop manual of the arm on the cam where all 3 carbs meet is in a different angle than mine is)????
So to recap,
I have the fast idle cable adjustment used all up
The idle screw adjustment used up
All the timing marks appear to be in the correct position, all the motor levers, arms, etc moving freely, lubed up nice.
The carb cams set a bit different on all 3 carbs
rust marks on the carb cams where it looks like the screw may have been seated at one time, but NOT NOW
All 3 carb mixture low speed adjustment all the same (1 1/12 turn out)
A idle of 900 RPM
Confused Joe