Link n Sync Help

[mercurymang]

I have a '75 650 3 cyl with a distributor. I took it out last night and I could hardly keep it running at idle. I tried to do a link n sync on it today but I have a question. I am able to the throttle pick up point which I have at around 4 degrees as well as the cutoff point which i have around 23 degrees. The thing I'm not sure about is the idle. When the mercontrol is in neutral, my spark is around 10 degrees After TDC. When I get underway, I don't hit my pick up point until the throttle is past 45 degrees or so. I feel like the throttle has to gar way to far before it's opening the carb up and hitting the pickup point.
Can someone help me fill in some gaps on this?

 

[jimmbo]

These engine do most or all of the spark advance with the carb butterflies closed or nearly closed. Once full advance occurs then the linkage opens the carb. By doing it this way allows, once the boat is planning to close the throttle greatly while maintaining full advance. This is what Mercury call the Fuel Economizer linkage. Also, the old MerControl boxes used until about 1978, were not very linear. Almost all the go-go was in the final 25 degrees of rotation

 

[mercurymang]

Perhaps a better question is what is the correct procedure to adjust the throttle cable?