1984 75HP Mercury won’t go over 1800RPM

[DoingTheBestICan]

My Mercury won’t get over 1800 RPM in gear. Idles and starts perfectly but as soon as I put it in gear it cuts off. If I put it in gear quick and push the throttle down it runs but will not get above 1500 - 1800 RPM, when I slow it back down to idle it often cuts off. I’m guessing this could be a clogged carburetor or should I be looking at something else? I just got this boat and it sat without being tun from October of last year till about 2 weeks ago. Thank you for your help.

 

[racerone]

Basics to be done.-----Are both carburetors opening up?----Compression test numbers ?-----Spark on all cylinders ?----Severe damage can be done by running with a suspected clogged carburetor.----Cleaning them is a good idea.----Tried opening the low speed mixture needles 1/2 turn ?