carburetor idle issue

[millz90]

just wanted to see if any one knew if there was a spring of somthing that i am missing on my carborator.

I have a 1995 175 Series so it has a Mercruise 3.0 in it.

The flap covering the injections just flaps around and doesnt open or close based on where the throttle is. (Shouldnt the flap open ALL the way up when i have it floored and only open a little at idile?

I tried to take pictures of the mechanisim which looks like it should be attached to where the throttle cable comes in.

If there i am missing a spring or something can i buy the top end of the carb only? Anyone have the guts to get ride of?
I believe this is part of my issue why its idiling so bad.

 

[millz90]

Does anyone happen to have a place or a PDF of a guide to ALL parts on the carbuertor? I could see what parts are their and what the guide has to determine if something has fallen off.....?

ANY help would be appreciated!

 

[chumbley]

The plate you are pointing to in the pic is the choke plate. It should be partially closed when cold, then open (either via electric or mechanical choke heater). After the engine is warm, it should be open (and stay open) all the time. There is a choke over-ride which pushes the plate open slightly at full throttle (to help clear flooding), but that's not in play here.

Sounds like you are missing some of your choke linkage or components, but I can't tell from the pics which ones.

 

[millz90]

So would that make it so i could set the idil speed correctly? I am having an issue where when i put the boat in gear it sounds like its ripping the gears out and then it takes off there really isnt a slow speed when the boat is in gear making it tough to dock it also goes in reverse REALLY hard.

 

[Scottbenson]

The hex shaped brass screw on the right side of your 1st carb picture is the idle speed adjusment screw. If you turn in counter clockwise, your engine speed should slow down at idle. Correct idle speed is approx. 750 RPM. If you idle speed does not change when you turn this screw, your throttle cable could be too tight which is holding open the lower throttle plates open a little.

 

[BonBini]

If I could add to what Scottbenson said: That idle adjustment screw looks to be on a cam. Meaning when the choke plate closes some, the engine will idle faster. Play around with it some and you'll see how it works. Also on that cam lever, there is most likely a hole in the end where a peace of choke stat control linkage would go. If you cant find the choke stat control linkage, you could wire it off via where the choke linkage would normally go. May be a little cold blooded. Getting a choke stove working on it would be the way I’d go.

 

[millz90]

Great i will check it out tomorrow.

 

[chumbley]

If that choke plate is loose - wire it open. Then work your idle issue. Then go back and figure out the choke thing.