It will start as usual, run at speed, and idle with a slightly advanced throttle all day (hours and hours i've run it). But when I put the throttle back to 0, it stalls out. 100 hours on the motor, model year 2000, bought new. It sat for about six months being started occasionally, but would not idle then either.
Emptied the gas tank and put in fresh gas. No change.
Replaced the plugs. No change.
I ran a 4x solution of carb treatment through the engine (two jugs in six gallons of gas) at slightly advanced throttle. Emptied the tank and put fresh gas in. No change.
Sprayed lots of carb cleaner at it, running and not running. No change. I've sprayed carb cleaner down all the air inlets and bleed ports. No change.
It's got 3x2 barrel carbs, and they look very clean inside.
I have not adjusted any screws, needles, or linkages on the carbs or motor to attempt to rig it, or otherwise fool around with it (although i know that tweaking the throttle linkage forward would make it idle, i know that's not the right solution). The **** service manual is back ordered, so I'm in the dark about what does what.
Thoughts? Suggestions? PDF files of relevant pages in the service manual? I really don't want to take it to a dealer, i want to fix it and understand what's wrong with it so i can take care of it myself.
Thanks.
Mercury 175 XR2 powerhead won't idle
Linear Mode
