Old Johnson Powershift II 85hp

[mdk0420]

Hello. Newer to the boat scene so still learning a bit about boat motors. Only ever worked on cars and motorcycles.

First and foremost I need to figure out this engine's year. Unfortunately it seems like the plate on the transom mount is gone. I assume there will be an engraved serial number somewhere on the block or some components that I might be able to work it down to the model year. The motor isn't original to the 1988 bayliner that it is on. Its a 4V Johnson Powershift II 85 HP 2 stroke motor. So my first question is where should I try to look for some identifying numbers? My initial looks found me nothing but its pretty dirty in there so it might be hiding pretty well. From my research it seems that the powershift models were made between 1973 and 1976. The 1976 apparently had a green lower. Mine does not. So I have a small range of years but if I need parts I want to make sure I'm ordering the correct year parts for it.

For the issue that I'm having it seems to be related to the choke. I was having throttle response issues which I removed the carbs, make sure parts were good cleaned up the injector pins (One was clogged and another partial), and it runs real nice now. The problem is starting it...

I'm not entirely sure what the issue could be with the choke solenoid yet. When I removed the carb assembly I sanded down the ground connection before reinstalling. It seems like a very expensive part for some reason. I guess they just don't make them anymore. So I would like to diagnose the issue as much as possible before spending $100 on one. Its odd that it works sometimes and other times it doesn't. I haven't traced the choke switch yet. That will be my next step.

EDIT: I'm a little confused on the choke situation. I found some comments about some years having a dual choke or a thermal electric choke. Someone posted a picture of what the usual wiring is which seems to have the one choke wire connected to this thermal switch. Mine is not setup that way though and looks to be bypassed. So both wires are connected to the choke switch. The reason this confuses me is on how the choke still operates automatically. I'm going to go back out and see if I can find a 4th wire but I'm pretty sure I only saw three wires which would be the two choke solenoid wires and the choke switch wire. Definitely something fishy here since if it is bypassed, I would assume the choke switch should just open it on and off and nothing more. But something is stopping it from operating and it seems maybe have something to do with the thermal sensor

 

[mdk0420]

Just a quick reply. I still don't know exactly what year my motor is but they look fairly similar. I found the choke or what looks to be the choke and it actually looks like. I deleted that part of my post because it seems irrelevant since apparently thats how the spring is actually designed. I'm still not sure about the wiring though

 

[jimmbo]

Post a Picture of the Cowl

 

[mdk0420]

 

[jimmbo]

I asked for Picture of the Cowl, but there was enough of it in the Pic. 1973

A 73 wouldn't have a Water Pisser. Someone has been butchering
Defiantly needs a Prop, and a Skeg

 

[mdk0420]

I asked for Picture of the Cowl, but there was enough of it in the Pic. 1973

A 73 wouldn't have a Water Pisser. Someone has been butchering
Defiantly needs a Prop, and a Skeg

It must've cropped the rest of the cowling out. I know about the minor things like a prop, needs new coil wires, and a few other small details. Mostly worried about the choke issue.

I'll have to look at a wiring diagram to see if I can trace what's going on with it. I thought I had it running on the automatic choke after manually choking it but after messing with it a bit I must've been mistake.

Having it on automatic choke just doesn't work at all. If I choke it, start it up it chugs and eventually bogs down and shuts off. It probably gets some fuel going so when I put the choke to on it starts right up and runs good once it's running. Would be nice if I could just get this solenoid to operate correctly so I can choke it from the console. But it's hit or miss if it works.

I haven't found a consistent result with the choke switch on the throttle controls. Sometimes it works, sometimes it doesn't. Sometimes it just stops in the middle of turning the motor over. Sometimes it works while the motor is on and I can force it to bog down flipping it on and off.

Does the powerhead look original? Or did they just run a Water pisser for some reason?

 

[jimmbo]

 

[mdk0420]

View attachment 388161

Thank you. I'll be running some tests tomorrow and see if I can solve the issue. I have a feeling there are some wiring issues. But could be the solenoid too I suppose.

 

[brodmann]

That's a great wiring diagram! Very simple and clear to understand. Wish I could find some like that when I have issues. Looks like the solenoid is grounded by the mounting surface, so giving 12v to either lead should activate it, right? To make sure, check resistance between the two wires coming off of it. If there's little or no resistance, then both wires do the same thing. Basically activate the solenoid. I think adding the tell tale is a good idea, but it could have been done a little "prettier", with a grommit for the hose to go through and not just hanging out. But that's just my opinion. Maybe we're going strictly for function. I certainly get that. My dad had a 70 HP about that same year model. The choke switch on the remote control is a toggle switch, right?

 

[jimmbo]

If you are referring to the Choke Solenoid, it is a two stage Solenoid, hence the two Inputs

 

[F_R]

That motor came with a two-stage choke solenoid. There was a factory service bulletin advising to move the SOLENOID wire coming from the thermal switch over to the terminal strip screw which presently holds the solenoid wire coming from the choke switch (along with the present wire from the choke switch). When done, operating the choke switch activated BOTH choke solenoid windings for a cold start-up (and ONLY when the driver operates the choke switch).

This removes the thermal switch from the system and eliminates the unwanted over choking problem.