1975 Evinrude 85HP Outboard

[Yammerhead]

I have an 85 Evinrude that doesn't want to start cold. I can crank it forever with the cold start lever up and the electric choke on without even so much as a pop.

The primer bulb has been squeezed to fill the float bowls. I then cracked the bowl drains and let a bit of fuel out. I could then squeeze the primer a bit until it got hard again. That tells me the bowls are full and the floats / needles / seats are working.

I removed the carbs and cleaned them. They were pretty clean. I only found a bit of debris in one of the small (pilot?) jets. I put it all back together again with the same result, it would crank forever with no fire.

I shot a bit of gas in the throttle bodies and actuated the electric choke. I cranked it over and it immediately fired and ran at high idle. I shut it off and it would restart again right away. I put earmuffs on it and restarted and it ran good, shifted well and everything. I put the covers back on, quite happy with myself and left it for the night. Next day, I went back out and tried it. I cranked it over and again, it would not fire. I pulled the covers off, shot some more gas in the throttles and it fired up again instantly. Runs good. I tried restarting it a couple it of times over a couple of hours and it fires instantly each time. Next morning, no go again.

Any ideas as why it won't fire at all when its cold? There is gas in the bowls, but it just seems like it woun't pull the gas up into the throttle bodies when cold. Should I add a primer circuit to squirt fuel into the throttle bodies to get it running??

 

[thellcon]

Re: 1975 Evinrude 85HP Outboard

I have the same year and hp evinrude
1. have you done a link and sync and set the pick-up timing at 4 degrees btc this is very important do it by the manual!
2. remove the air intake cover and visually verify that the chokes are closing fully when cranking. If the vaccuum created when cranking causes the chokes to partially open adjust the spring on the top of the choke selonoid so that the choke is completely closed as you crank the engine.
3. If you have a tilt and trim, do not drop the engine to its lowest point keep it level for initial start up.

Try these 3 things before all else.

 

[F_R]

Re: 1975 Evinrude 85HP Outboard

Do you know if the choke solenoid has been rewired? That was a service bulletin.

Anyhow, that is a dual winding solenoid. There should be two wires going to it, purple with white stripe and purple with yellow stripe. First thing you want to do is make sure the solenoid is good. Use a jumper wire from the big red battery cable to one of the choke wires. It should close at least part way. Then do the same to the other choke wire. Should also close at least part way.

Having verified the solenoid is good, but BOTH choke solenoid wires on the screw with the purple/white wire from the harness. Ignore the other purple/yellow wire from the thermal switch, it won't be used any more. With it wired this way, activating the choke switch should slam the choke shut tight and it will start.

 

[wildmaninal]

Re: 1975 Evinrude 85HP Outboard

How long have you owned this motor? I'm not disagreeing with anyone else's post, but if you are new to this motor there is a cold start procedure to follow. Also just to give you a little something to go by, here is a pic of a 85hp motor within the same year as yours, you can compare the picture of yours to this and make sure the marking are lined up with the carb throttle roller as in the picture. This picture shows the position it should be set in when in idle (not warm up position).

For the record this motor in the picture above hasn't had the carbs taken off sense this relative bought it nore has it had any adjustments and this was a running motor.

 

[KewlBird]

Re: 1975 Evinrude 85HP Outboard

I have a same year Johnson and had a same problem. The issue on mine was that the choke plates were not closing completely.
Take your silencer cover off and look at the choke plates when you activate them, they should be completely closed. If not closed completely adjust them. If the choke solenoid was not positioned right after being removed it can interefere with the operation. The choke linkage was hitting the solenoid wires when actuated on mine, so all I had to do is reposition the solenoid.

I know this repeats what thellcon said but it very well maybe the issue.

BTW, I too was looking into putting in primer solenoid until I fixed the problem.

 

[F_R]

Re: 1975 Evinrude 85HP Outboard

This is part of what I wrote about. There are TWO windings in the solenoid. BOTH must be energized for a cold start. One of them will close the choke plates, but not tight enough. That is one reason for putting both wires on the purple/white screw, and the reason for testing to see if both windings are good. The doors have to be closed against the plunger's spring pressure if you want it to start. The other reason for the wiring modification is to prevent flooding during warmup, but that's another story.

 

[thellcon]

Re: 1975 Evinrude 85HP Outboard

FR:
I have elminated the two stage function of my choke but that is an unrelated issue. Eliminating the first stage has more to do with the temp sensor waiting too long or not working at all so that the engine remains at 1/2 choke. When the key is turned to the on position the choke would go on halfway, then when the switch for the choke is lifted the engine goes to full choke, releasing the choke switch would then let the engine return to 1/2 choke untill fully warmed up. I do agree that my engine warms up 100% better since tying the two purple wires together.

Wildanimal:
Not to be contradictive but on the picture of the engine you provided the choke to throttle link that pulls off the choke at full throttle is missing entirely and the idle screw is not resting against it's stop so some carb work has definately been done.

 

[Yammerhead]

Re: 1975 Evinrude 85HP Outboard

Thanks guys, great info here. I went back out this morning and watched the choke plates. They were fluttering when the engine was turning over. The spring connecting the solenoid plunger to the linkage was stretched out pretty badly. I shortened the spring to put more tension on the linkage and viola, the motor fired up.

I checked the solenoid wiring and the purple wires have already been connected to the same terminal. Hopefully should be good to go!