float adjustment for mercarb kb 12 a

[ab2df]

I was having trouble with an old 70's mercury 7.5 hp 75 I got from my neighbor. Put some new parts into it and cleaned the carb. But I was getting some surging while running it. I ordered up new needle valve and seat, and gaskets but I'm not sure how to adjust the arms for needle valve / float. the carb is a mercarb k 12 a similar to k 11 a (which is the only one close I could find a picture of) much less float setting. Any help / info would be greatly appreciated. Thank you in advance. Sorry I have pics of carb but being new to forum I cannot attach them.

michael,
ab2df.

 

[jerryjerry05]

Shutterfly helps add photos.
​Someplace on your motor is a # that id's it.
Model# always add that when asking about repairs.
They use a bunch of different carbs over the years
Most carbs: float level.
Turn the carb upside down.
The float should be level with the body.
Then turn right side up.
​The float "drop" it should just about touch the main stem of the body.(depending on the carb)

​The air screw set at 1 1/2 turn out from lightly seated.

 

[ab2df]

The mercury is 7.5 hp (75) serial # 3274967. The float is not attached to upper carb. Body, it just rides on a center pin extending from the bottom of the float bowl. When you detach float bowl the float stays in it. Also there are 2 arms (one from left, one from right) that are above float to control the needle valve. Again the carb is a (mercury k12a). Thanks.

Michael,
ab2df.

 

[jerryjerry05]

That's something I've NO experience with.
​Actually never saw a free floating float?
Someone will help.

 

[ab2df]

Ok thanks.