1973 Mercruiser Inline 6 Starting problems

theck4291

Petty Officer 3rd Class
Joined
Jul 19, 2015
Messages
87
Finally got the boat into the water after my reno, and it is giving me a tough time starting. It just cranks and cranks, and will fire, but dies almost instantly, unless I have the throttle just under WOT. Any ideas or things to look for? Thanks guys, by the way I just filled the tank with 25 gallons of 100% gasoline, was that the right thing to do? Thanks
 

johnkom

Petty Officer 2nd Class
Joined
Jul 26, 2004
Messages
178
"...after reno." I'd guess fuel system. Can you squirt fuel into the carb and have it start? After a three year renovation on my old L6 powered boat, it was the anti siphon valve and junk in the carburetor bowl.

JK
 

theck4291

Petty Officer 3rd Class
Joined
Jul 19, 2015
Messages
87
it was only about a 4 month reno... and it was working fine before... i mean, it will start if i put it to wide open throttle, and slowly back it off, but once im in neutral it seems to be running rough.....
 

theck4291

Petty Officer 3rd Class
Joined
Jul 19, 2015
Messages
87
Carb Questions

Ok, so I am new at working with carbs and don't know much about them. Here is how mine is set up right now. The butterfly is closed at cold, does that need to be adjusted so it is open? Also when I put it full throttle my FIL said that the butterfly should close? Mine does now. How can I correct this and/or how is it supposed to be when not running, trying to start, and running WOT? 1973 Mercruiser inline 6
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,344
Generally speaking with the throttle advanced on a cold engine, the choke butterfly should close to within an 1/8 inch.
Most carb`d engines need a few pumps of the throttle to get a squirt of gas from the accell pump circuit and then need the throttle slightly advanced when starting
either an electric element or a choke stove provides heat for the choke spring to open the choke plate.
Google it, theres a ton of carb info available
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,079
Ok, so I am new at working with carbs

Ayuh,.... 'n probably has everything to do with yer startin' problem,....

All one issue, so keep it All in one thread,.....

I merged the two ya had goin',...
 
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