1990 80HP 2 Stroke surging, then dying

Hello, I'm a new member looking for some help with a boat that's new to me. It's a 1990 Rinker 16ft runabout with a Merc 80hp 2 stroke. I just purchased it for this season. Last week, when I got it in the water for the first time, it was a bit hard to start, which was to be expected, since it was winterized. Once I got it started, it idled fine for about 20-30 seconds, I got it in gear and it started moving pretty slowly. There was a noticible clicking that got louder over the next 40 seconds, or so. Then, the RPMs shot up to 5,000 and pinned there until the boat eventually died out. The motor was lightly smoking. The motor would not turn immediately after that. It would only click when I turned the key. I was able to paddle the boat over to my slip. About 2 hours later, I was able to start the boat again. It idled for about 30 seconds, then pinned at 5,000 RPM for about 20 seconds, then died. The general consensus is that there is a problem with the choke sticking. The lever that controls the choke does not seem to visibly move anything in the motor when it's operated. There are two rods on the right side of the motor. One of which controls the throttle and the other that I presume controls the choke. I am somewhat mechanical, but this is the first time I've ever seen the inside of an outboard, so I'm lost. Any suggestions or troubleshooting ideas would be greatly appreciated.

Photo:

https://www.flickr.com/gp/141392619@N04/7F748x

This motor may not have choke flappers.------It may have an enricher system.-----You will not see anything move when it is operated.--------One rod may be for the oil injection system.------Do you know if oil injection system is in service or bypassed ?------Did the seller go through the operation / starting procedure with you ?-----------Best to find a manual as mistakes can be very costly.

Thank you for the response. The seller went through normal operation with me, but not anything technical. I contacted him when I begun having problems and he has offered some suggestions, mostly involving the choke. I mix the oil myself. It is 50:1. There doesn't seem to be an injection system on the motor. Does the picture I posted give you any indication that it has a choke or enriched system? Thanks.

I can push the key forward to prime the fuel system when starting. Would that mean that I have the enrichener system?

If you have the year correct it should have the enricher system as opposed to what you may think of as a choke.

The enricher is simply a little valve, electrically operated, the "opens" when you push in the key (to choke prior to starting - key switch sends a small charge to the valve) - and the valve allows some fuel to flow from the upper carb to all three intakes (see diagram below).

Now, this does make a "clicking noise" when you push in the key - you should hear one click when you push in the key and as long as you keep it pushed in the valve will stay open and fuel will flow, bypassing the carbs going right into the intake to help with a cold start.

From what you describe it is "possible" that either the enricher is malfunctioning, or you have a short somewhere in the harness or you key switch is defective and it's activating while you are running (so MAYBE all those clicks you are hearing is the enricher valve operating dumping fuel right into the intake which is in turn causing the high rpm surge.

But you may have a combination of issues here. I am always suspect of any motor or boat/motor that is sold used. The owner didn't get rid of it because it was "perfect" - they most often got rid of it because it rarely got used which in turn means that it most probably didn't see any maintenance for a few years. Typically, they stopped using it all together and after a few years of "sitting around", the significant other finally nagged enough about "getting that eyesore" out of the driveway or the back yard.

Because of that you should undertake a bit of rehab before you ever try and use it for the first time.

That would typically include: cleaning the carbs (and rebuild if necessary), change the spark plugs, check the fuel flow from the fuel pump, replace the oil in the lower unit, minimally inspect the water pump but putting in a new impeller (at minimum) is always cheap insurance of an overheat. Check all the wiring for fraying, damage from mice etc.

I don't trust ever what the previous owner tells me and unless it was bought from a dealer that offered "some warranty" you have to assume "it needs work before taking it out".

Anyhow, here is what the enricher looks like, and it is somewhere to start, but without giving the entire motor a good once over you could find yourself stranded with a couple hundred pounds of scrap aluminum.

Thanks. I suppose that I was referring to the high idle lever that I pull up before starting as the "choke". This is the thing that I thought was sticking. I assumed that moving that lever up and down would mechanically move something back by the motor, though nothing moves. Also, I noticed that when I squeeze the fuel bulb, it seems that it never gets truly firm. It sounds like air/liquid is being pushed into the motor when I squeeze it. I remember that prior to this issue, I could get that bulb pretty firm and I didn't remember being able to actually hear something going into the motor. In other words, it seems like the fuel is bypassing any type of system that would prime it for starting. Squeezing the bulb now eventually leads to fuel leaking out of the motor. Not sure if that is normal, if you squeeze the bulb 3-4 times. What is the best resource for finding a manual for this motor? Thanks again.

There are a couple of manual options.

First there is Seloc's - many guys are "not fans" of Seloc's but I find them more than adequate (and affordable) for the average guy going at one specific motor in their driveway. Covers just about everything you could ever need plus gives you "tips, do's and don't) - sell for about 35 bucks or so - can get them in print or on-line (this site sells them as an example, as would most marine dealers).

Second option is the Factory Service manual - absolutely more detailed and more specific to your exact motor. But it also assumes the user is a Marine Mechanic and familiar with such things as not using carb cleaner on Marelon parts (because it will eat them) - Selcoc's will tell you bits like that, the service manual will not. The last service manual I bought was up in the 80 bucks range - don't know today's "going rate" but can be sourced through any Merc dealer.

Your fuel bulb not getting hard could be a symptom of a few issues.

It could be simply a loose connection somewhere on the fuel lines - you would see gas coming from "somewhere" if that was the case.

The bulb itself might be shot.

You could have a blown diaphragm in the fuel pump and the "extra gas" is passing into the lower crank case (think of internal "flooding").

You could have one or more toasted float valves, again, will cause flooding.

But do grab a manual and tackle one issue at a time. Solve your fuel bulb issue and it may clear up your downstream problems. If not, at least it's not working against your other troubleshooting.