RACING idle- ideas?

diggerdpilot

Cadet
Joined
Jun 14, 2009
Messages
8
Hi all,
I have a 175HP '88 Johnson. Runs great, normally. Last outing, a shift link bushing cracked, giving me fits that day. Replaced it, and upon starting it today, it goes almost immediately to around 25-2600RPM on startup, with no choke. It was always a bit coldblooded before. If I hold the key in and keep it choked, it will knock down to around 1600. I realize this is on muffs, but I cant get it down to the point to trying the gears, let alone stop gritting my teeth.

I recently blocked off the VRO system (oil alert-will run premix, just one less thing to break). I am running a bit rich pre mix now.

I have pulled the carb shroud, all intake butterflys are closed fully.
I have pulled the throttle linkage at the barrels, still races like this. Linkage is letting the carbs shut completely, even to the point of the stop off the block.
The solenoid lever is in the normal position, and since the choke will decrease the RPMs, I assume it is working.
I reconnected the plug that sounds the oil alert. No change.
I cannot find any evidence of an air leak in the intake system at all.

I considered the timing jumping, but seems kinda a long shot, plus, with the fuel at idle, figured it would run worse. It runs super high, but sounds good.

I would love some help on this one. I even went to the point of putting some duct tape on the hub to try to see if better backpressure would help. I have not put it in the ramp yet to see if water would do this, but I have doubts about it helping. Of course, this happened the night of the fireworks on the lake.

Welcome to boating, kids!
 

mikew2012

Cadet
Joined
Jul 31, 2012
Messages
9
Re: RACING idle- ideas?

Hi,

Did you ever resolve the racing idle? i have the exact problem you have on a 88' johnson 70hp and its driving me mental
 
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