Can't find idle scew on 87' Merc 120HP 4CYL. Need to turn it up.

[Fordiesel69]

I feel dumb now. I cant find the idle adjustment screw. My choke spring housing was so loose it was almost ready to fall off the carb. I got it all tight now but as you know if was sucking air and allowing it to idle just right. Now that it is tight, it idles too low.

BTW, it is GM/Rochester carburetor.

 

[Bondo]

Re: Can't find idle scew on 87' Merc 120HP 4CYL. Need to turn it up.

Ayuh,... All the answers about that motor,+ drive are in Service Manual #1, which is available in the Adults Only section of this forum...

 

[Don S]

Re: Can't find idle scew on 87' Merc 120HP 4CYL. Need to turn it up.

Can't find idle scew on 87' Merc 120HP 4CYL.

If it's actually an 87 engine, you need manual #10

 

[Fordiesel69]

Re: Can't find idle scew on 87' Merc 120HP 4CYL. Need to turn it up.

Sorry, its a 74'.

I cant download the manuals. My computers at home and at work, say file is corrupt.

could you just tell me where it is.

 

[Don S]

Re: Can't find idle scew on 87' Merc 120HP 4CYL. Need to turn it up.

You will probably need to adjust the idle mixture and speed. Here are pictures of both.

 

[ErieRon]

Re: Can't find idle scew on 87' Merc 120HP 4CYL. Need to turn it up.

If you want, send your email address to me in a PM and I'll email you the applicable pages.

 

[Don S]

Re: Can't find idle scew on 87' Merc 120HP 4CYL. Need to turn it up.

There are 3 different links in the adults only thread for downloading the manual for #1, and I am sure that none of them are corrupt.
If you need small downloads, use this link
http://www.4shared.com/dir/17398521/84b1864e/1sharing.html
Then just scroll down and download the cover. It has the index in it so you know which ones you need to download. You need section 4B for your carbs.

 

[Fordiesel69]

Re: Can't find idle scew on 87' Merc 120HP 4CYL. Need to turn it up.

Excllent illistrations. That solved the problem.

I had the cam in the wrong place after having the lid off the carb. I still had to bump it up 1/2 turn though probably because the the air leak I had.