1994 115 mercury missing and alarm going off not reaching 5200 rpms only 4400 rpms

i just picked up a 17 whaler 1973 with a 1994 mercury 115 engine. it is all in very good condition, but the last owner only ran the motor on the muff a few times a year for two years. i looked it over and it looked fine. i put a 12 galon tank mouler fueled up 89 octain and qicksilver oil all new. man, it cranked right up i headed out gave it the gas and up we went but it started missing. it caught up and ran fast, but each time i tried to get it up it would miss and than find it self and run but the max rpm would be 4400rpm i thouht it needed to be run. was that a mistake? i ran it for 2hours stoping starting pumping the ball trying to run it out of her. when she was running she ran great but never could get 5200 rpm. on the way in she really seemed to stop missing. at the end i was taking it easy 3200rpm and the alarm goes off and stayed on until i walked it home slow.
someone told me if it is a fuel issue i could be in trouble because the fuel goes in to the carbs on the bottom and it was not getting fuel to the top carb; therefor, the top pistons were not being lubed from gas and oil and i could have damaged the top of the head. what should i do. bring it to a mercury man. are change the plugs and fuel filter and try it again. it ran fine on the muff after this trip. i cleaned the plugs and it really fired up. no missing and alot of reaction to gas. no alarm sounding off. do you have any advice?

Re: 1994 115 mercury missing and alarm going off not reaching 5200 rpms only 4400 rpm

Sitting up that long could have resulted in varnished carbs which results in clogged jets.

Higher speeds under loads like you mentioned require more fuel. If the jets are clogged, the engine cannot supply enough fuel to run at the higher rpm's under load.

What you say is true about a carb not supplying fuel to that cylinder. Removing the spark plug and looking into that cylinder may allow you to determine if you have any damage. Look at the plug tip for metal shavings...shouldn't be any, and look at the sides of the cylinders for scoring....should be mirror shiny. Look on the head of the piston for alum chips....shouldn't be any.

Rebuild your carbs and might as well get a fuel pump repair kit.

HTH

Mark