merc 165 carb idle adjustment screw???

[bribraf]

I have a 1970's era merc 165 inboard straight 6 cyl GM motor with a rochester 2 bbl carb that I just had rebuilt and I can't locate the idle adjustment screw.My manual state's that it is hidden somewhere in the back of the carb by the throttle assembly,but I cannot locate it.I have located the idle fuel mixture two screw's but not the actual idle screw.Can somebody offer any advice?

 

[1972 searay]

Re: merc 165 carb idle adjustment screw???

here is a webite with the instruction sheet for the model 210 rochester carb.

http://www.surplussales.com/Automobile/Carburetors/pdf/ato-77-1312.pdf

 

[1972 searay]

Re: merc 165 carb idle adjustment screw???

reference number 51 is the idle adjustment screws. good luck.

 

[jtybt]

Re: merc 165 carb idle adjustment screw???

Ya know, I looked at the schematic and didn't see the idle adjustment screw.

#51 is the low speed air screw.

The idle screw is usually on the port side of the carb...same side as the throttle cable. It HAS to be pressing on a tab that is attached to the throttle plate shaft that goes thru the carb. I is usually a little above the throttle shaft and pointed at a 2 o'clock angle.

 

[ziggy]

Re: merc 165 carb idle adjustment screw???

the screw on the bottom right is the idle speed screw (all ya can see are the screw threads of the screw in my pic). it's on the same lever that the throttle cable attaches too. normally it rests on the cam. when turned, it slowly opens the throttle plates. item 51 are the idle mix screws..

 

[bribraf]

Re: merc 165 carb idle adjustment screw???

the screw on the bottom right is the idle speed screw (all ya can see are the screw threads of the screw in my pic). it's on the same lever that the throttle cable attaches too. normally it rests on the cam. when turned, it slowly opens the throttle plates. item 51 are the idle mix screws..

Hey ziggy thanks for your help I found it.But now problem is that the idle screw is not long enough to open up the idle,it needs about another 1/8 of an inch.Is this a common problem?What should I do?

 

[Rob_NC]

Re: merc 165 carb idle adjustment screw???

..then the cam has flipped around...some one been working on the choke...

 

[ziggy]

Re: merc 165 carb idle adjustment screw???

ok, now i remember my sequece of events and why it's not happened to me for a while. that cam can flip onto the wrong side. when i rebuilt my carb. i rebuilt the one off my trisonics L6. so i don't have the carb on my boat that it came with. it's in the basement. i just went and fliped the cam onto the wrong side. it put up a little resistance but it did flip to the wrong side. w/o looking at it to close, i'd think worn linkage holes or pivot points allows this to happen. i know it's not supposed to, but it does on the one on my bench and i remember it happening when it was on my boat too. i believe my first sign was the choke worked improper and thats where it lead me. flip the cam back and i was hip. perhaps this has occurred with the op too.
the screw needs to be pointing at the curved side of the cam. not the back side. if the screw is pointing towards the back side of the cam, it won't reach. the screw should be pointing towards the curved part of the cam. the choke linkage would come down on the starboard side of the cam and looks sraight up and down. if the choke link is tilted to port at the bottom where it connects to the cam, it's fliped over...

if ya want a pic of what i just said, let me know. i can probably snap a few off for ya..

 

[Rob_NC]

Re: merc 165 carb idle adjustment screw???

..good....