Merc 850 Died when shifted?

[Chrisravosa36]

1973 Merc 85hp (850) 4cyl
Brought to the marine and said it looked good, changed plugs. they also said it just needed to be ran. Wasn't running for a few years


Hello, I'm am new to this forum and I had a infesting adventure today. I got to the boat ramp, tried to start the motor, put the nutria Rpms to half, then I held the choke and turned the key, started then I put down the rpm stick all the way and then shifted and died, after 15mins I got it started I had to keep the neutral rom stock somewhat up when running it, it did out a few ties on the water, and took a few minutes to warm up with the rpm stick at half then shifted to forward, sometimes it would start or it wouldn't. We ran it for another hour or so and got it so you don't have to run it with the rpm stick.
So I'm not sure what the problem is and how I can resolve it, I've looked up a lot of things, it could be sucking air? The carb could need to be cleaned? It needs to be run? Not sure what to do? The motor seemed to have gotten better from the start of the day till the end. I'm going out tomorrow and wanted to see if there where any suggestions ? I was considering bringing it to the shop.

Any advice is welcomed!

 

[Chris1956]

That happens all the time with motors like yours'. The usual suspects are dirty carbs, misadjusted idle mixture, idle set too low, idle timing incorrect.

You might also check the spark plug wires for arcing. Be real careful with the distributor cap and rotor. They are real expensive, and the rotor is non-removeable.

If it were me, I would get a Merc Service Manual and check the timing, compression and spark to all cylinders. Then clean the carbs and adjust the idle mixtures. It is likely the carbs, but rule out the other stuff first. Cleaning the carbs means clean the metal parts, install new floats, inlet needle and seat and gaskets.