Mercury 7.5hp starting problem

[bryemotors]

I have a 1973 7.5hp Mercury outboard (serial 3730677). The motor will
only start when I spray gas in the carb. The choke seems to do nothing but
it does close all the way when its pulled out. Once the motor starts the first time it runs fine the rest of the day. I have cleaned the carb out and put in a new needle and gasket kit including the diaphragm. Can you tell me how does the gas get into the carb when the choke is on? Also how do I make
sure the float level is adjusted properly? The motor does run good at all
speeds, just the initial starting I have to pull the cover and spray a little
gas in it and it takes right off. The carb is a Mercarb BB-2A.

 

[woody66912]

Re: Mercury 7.5hp starting problem

make sure your low speed needle is out 1 1/8 to 1 1/4 to start with. then with engine in gear set at lowest idle speed turn in low speed till it sneezes then back out 1/4 turn .the fuel comes up the high speed pick up tube and many other circuits when you close the choke.after your first start up you have fuel puddled in the crank case witch will scavenge into the combustion chamber allowing it to start the rest of the day.

 

[8075mercury]

Re: Mercury 7.5hp starting problem

I agree with above, a little too rich is better for starting than a little too lean.

When you start it cold, you might try the following which usually always works for me (these motors can be finicky to cold start):
*bulb tight, choke out (make sure if closes fully which you said it did)
*throttle at fast idle or start
*slow roll it over with the pull cord about 8 to 12 compression strokes
(if it starts here, push the choke in super quick)
*if it does not start during the slow roll, first pull the rope out about 2inches to engage the starter pawls, and pull the rope super quick about 2ft.

Good luck and super little motors !