1981 90hp merc vacuum hose question serial # 5783439

motor serial # 5783439 on the back side of my motor, between the spark plugs there is a vacuum hose that comes out. I believe its suppose to connect to something like the fuel regulator, or something. The opposite end of the hose is cut off and missing. I'm not sure where the location is that the other end is suppose to connect. I've searched many times, but i cant find any parts that look to be missing a connection like a vacuum hose. The engine seems to run just fine and smooth. This vacuum hose will drip a little water sometimes while the engine is running. It was like this when i bought it, I downloaded (purchased) a very extensive manual for this motor online, which is very informational, but this manual covers many different motors of that type but varying sizes. I'm a little lost, but I have a brand new replacement vacuum hose that has brass threaded connectors, looks to be really easy to switch out. But i'm wondering if i have to disassemble much of the engine to find the location of the part. Thanks alot for any helpful tips.

Re: 1981 90hp merc vacuum hose question serial # 5783439

More than likely it's for a water pressure gauge at the helm. Some of the older towers used this location for the tell tale feed, but I believe on yours the tell tale should be plumbed off the top of the block. Check where your tell tale is plumbed to, if to top of block and you don't have a water pressure gauge, you can remove barb fitting from engine and install a pipe plug, should be 1/8" npt.

Also, if you're only getting a drip of water from there, and the hose/fitting is not blocked, recommend servicing the water pump.