Merc 3cyl. 650 Won't Idle

robtmyer

Cadet
Joined
Oct 21, 2003
Messages
16
I runs good at high speed but stall's at low speed's. With Warm-up lever at full overly fast but when you pull lever to mid point or lower it dies then you must choke it to start it agian. It act as if it is out of gas but bulb is tight. Do you think idle curcuit is clogged or idle mixture needs to be adjusted? Buying motor with boat he said he had motor rebuilt. :( Used deep creep so far.
 

The Marine Doctor

Commander
Joined
Jul 25, 2003
Messages
2,177
Re: Merc 3cyl. 650 Won't Idle

If you have to choke it, it generally means a lean condition. Which means dirty carbs.<br /><br />The engine could also be worn out too.<br /><br />TMD
 

robtmyer

Cadet
Joined
Oct 21, 2003
Messages
16
Re: Merc 3cyl. 650 Won't Idle

Thanks for your advice Marine Doctor I hope its<br />dirty carbs and not a worn-out motor.
 

bob58

Petty Officer 2nd Class
Joined
Sep 27, 2003
Messages
114
Re: Merc 3cyl. 650 Won't Idle

Could also be sucking air into the fuel system.<br />Check that the fuel line from tank to fuel pump is in good shape and all connections are tight.
 

robtmyer

Cadet
Joined
Oct 21, 2003
Messages
16
Re: Merc 3cyl. 650 Won't Idle

Thanks you Still Learning I will check it out this<br />weekend.
 

robtmyer

Cadet
Joined
Oct 21, 2003
Messages
16
Re: Merc 3cyl. 650 Won't Idle

I ajusted Idle Mixture screws one turn counter-clockwise and it runs fine now.
 

bill cook

Cadet
Joined
Apr 6, 2003
Messages
12
Re: Merc 3cyl. 650 Won't Idle

I have had the same problem with my 650, 4 cyl. where is the idle mixture set screw located?
 
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