2005 90 hp idle adjustment

[bcj.jones]

Just rebuilt the carbs on my 90 hp 2 stroke mercury. Wouldn't idle before and now it idles great but a little high. My question is about the sequence of adjustments as the factory service manual is a little vague. I have the carb adjustment needles all 1-1/2 turns out from slightly seated. This gets it firing right up and runs great, but with it idling around 1800 rpms it'll slam into gear when shifting. I can turn in the low mixture speed screw and get the idle down to 1000 rpm's but it'll cause the motor to die when put into gear. I know there is a timing advance/retard adjustment "idle" screw as well. My question is, do I leave the idle adjustment screw completely bottomed out until I adjust the carbs, then once I get the carbs adjusted using the idle adjustment screw to slow the idle down?

I am adjusting the low mixture screw on the carbs with the boat tied to the dock and in forward gear

 

[racerone]

You need to adjust the idle stop screw.----The mixture adjusting screws should be left at about 1-1/2 turns out !!------The mixture screws are NOT TO BE USED to control idle speed.----Idle mixture screw may need to be adjusted with engine in gear at the dock.----If motor stumbles on acceleration you open needles 1/4 turn at a time.

 

[bcj.jones]

Yea, sorry for how that read. I understand that the mixture screws aren't designed to control idle, I was just mentioning that when tuning them in the idle would go down. My fault. They ended up running best at 1 1/2 turns like you said, anymore lean and it would lean sneeze.

Just for my knowledge as well, when screwing in the idle adjustment screw, does that advance or retard the timing? I'm assuming it retards the timing, but I hate assuming!

 

[racerone]

Idle RPM is controlled by changing the timing and NOT carburetion !------Fact----A 2 stroke idling needs fuel to go into the engine because fuel contains the lubricating oil !----You can not shut off the fuel to control idle speed.