Carb. throttle shutter plate

I just finished winterizeing my motor 1985 75hp seriel#6613274. I first sprayed Deep Creep into her and shut it down. While waiting for it to work it's magic I moved the throttle to wot. I noticed the upper plate was wide open while the lower was not. I can open it up an other 1/8th to 1/4 inch if I reach behind with my finger to the throttle shaft linkage. Is there an adjustment for this? I have a Seloc manuel but can not find any info on this. Also when I pulled the plugs the top two were a dark color while the lower two looked like they were brand new especially #4. Both idle/mixture screws are open 1 1/2 turns. By the bottom throttle plate not being wide open cause a leaner mixture. The motor ran perfectly all season. Am I just an old worry wart or should this be addressed. Thanks "God I love my old Mercury"

Re: Carb. throttle shutter plate

The connecting linkage is working a verticle throttle shaft on the old direct charge motors I believe--there is a tiny "plate" that the shafts slip over when putting them on. But the more critical adjustment is that both plates are completely closed at idle, or it won't idle. The bottom carb would atually be richer if partially open, would it not? But inspecting that plastic link between the carbs (I believe there is a sync adjustment on there somewhere) should ease your mind. I'm with you, those old DC 4 clyinders where solid.

Re: Carb. throttle shutter plate

Ben Thanks for the reply. I'll take a look closer at it when I get the melon jobs (honeydo's) finished today. The old girl,not the wife,idled just fine. Both are closed at idle.Thanks again

Re: Carb. throttle shutter plate

Just an up date on my problem. Adjusted lower carb. shutter so now both are at wot. Also took the Clams Canino crash course on timeing and sync. What a difference. Got the idle down were it belongs and she really jumps up on step when you punch it. The color of #4 plug still has me wondering but the motor is refogged and I'll just have to wait till next spring to deal with it. Thanks for the help