87 merc 3.0 cold starting

Thuffjr

Petty Officer 3rd Class
Joined
Feb 23, 2010
Messages
77
First off I would like to thank everyone who was kind enough to help me break into the boating world with my first 67 johnson out board. lol never did get that running.
At the moment I have a 87 mercruiser 3.0 that runs but Its a b*tch to start when cold. Usually i have to pull the dog house and spend about 30 mins every time i put it in the water. killed the battery more than once. When i finally get it running it runs great and will start right up after an hour of sitting.
I don't know much about carbs never had a car with one but im sure the problem has to be something to do with the carb. There is no choke as far as i can see and the butterfly seems to just swing freely at all times doesn't stay in one position. so to choke i usually hold the butterfly down while my wife turns the key. (not sure if butterfly is the right term. just what i have been told its called)
I hate being a nooby but i guess everyone is once
any help is greatly appreciated
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,082
Re: 87 merc 3.0 cold starting

I don't know much about carbs

Ayuh,... Odds are, you Need a New 1....

Up in the Adults Only section of this forum you'll find the factory manuals...
Download the 1s for you motor,+ drive....
You can learn about your carb in the motor manual...
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: 87 merc 3.0 cold starting

You could have several issues. Engiine may just need a tuneup, but from the sounds of ti the choke is not working
There is no choke as far as i can see and the butterfly seems to just swing freely at all times doesn't stay in one position.
The "Butterfly" IS the choke. and sounds like it's not hooked up or pieces are missing.
The accelerator pump in the carb may also be defective.
As bondo suggested, get the manual from the adults only sticky and study how a carb works. You should also be pumping the throttle 2-3 times to help prime a cold engine. It also sets the choke when it works.
 

Thuffjr

Petty Officer 3rd Class
Joined
Feb 23, 2010
Messages
77
Re: 87 merc 3.0 cold starting

Yea there seems to be a spring or something missing Im in the process of DLing the service manual Thanks allot
 
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