1978 Johnson 85 HP Choke Issues

[Bassboating]

First thank you to all who replied
Second it’s a 77 not a 78. Don’t know if that matters
Model 85ETLR77S
No. J4762735
4500 TO 5500 R P.M R.P.M.

 

[Bassboating]

Cut one piece of wire 24 inches long.----Remover 1/4" insulation from ends.----Find choke wire on the terminal. strip.----Find positive terminal from battery on the solenoid.----Touch one end of that jumper wire on choke terminal.----The other end on + solenoid terminal.---Choke solenoid should click.

To make sure the terminal strip is the power pack we just replaced?

 

[Crosbyman]

see similar.. design on a 1980 engine maybe not identical but just fyi
see the choke solenoid's purple white to the fat connector then over to the switch where it is activated as needed . (bottom right hand side of the switch diagram)

Power to the switch comes from the purple-red on the fuse and according to the switch position...... it transfers power (purple) to various parts (accessories, ignition, temp buzzer and... "choke" on it's purple white back to the "choke " itself

if everything works except the choke... either switch +12 on purple -white is not reaching the choke itself or the choke inner core winding is open... or the key's choke function is bad .

if you have such a fat connector check the plug's wire female-male surfaces for corrosion.

test to find your +12 with a simple one side grounded bulb or VOM while the key is on choke

wiring designs vary of course... ... this one is from the maxrules site which you can consult at this link
https://maxrules.com/graphics/omc/wiring/80_81_V4.jpg

 

[racerone]

Time to visit your local friendly boat shop and pay the mechanic I think.

 

[Crosbyman]

naaa....just some reading of DC testing and using a VOM on utube should provide basic skills. learning is half the fun !

 

[F_R]

First thank you to all who replied
Second it’s a 77 not a 78. Don’t know if that matters
Model 85ETLR77S
No. J4762735
4500 TO 5500 R P.M R.P.M.

No wonder you are getting so many incorrect replies. I wonder how many other things are wrong. Does it even have the correct carburetors? Or did somebody swap out some bigger carbs in a go-faster attempt?

 

[Bassboating]

So, this evening I found where the choke was going on a strip mounted to the top of the engine.
I took a wire and touched the positive of the battery to the screw head where the choke wire was terminated. Nothing happened.
I saw above someone said to turn the key and press in and then try that test, I may try that tomorrow.
I want to learn how this works and I have watched so many videos and read so many things I am starting to be able to pick the different engine parts out by site now.

 

[racerone]

By using the jumper you have bypassed the function of the ignition switch.-----No need to turn the key and push it in at all.----

 

[jimmbo]

I suspect the Manual Choke Lever was removed by a previous Owner, Why? who knows
It would have contacted the Roller#16, shown in your last Pic


Going through the Parts Books for both the 77 and 78, there were some Big Changes and some Little Changes. The Blocks are not interchangeable, Mid Sections are very different, as the Power Trim Systems. Carbs and Linkages are different, there appears to be changes to the Ignition Systems. Even the Air Silencer in front of the Carbs is Different

 

[Faztbullet]

If the tie is holding the choke position open the solenoid will not pull choke plunger down. It will only wiggle when activated

 

[Bassboating]

Well, lots has happened since this.
I found out my starter was all but dead, the bendix was not engaging and going up.
Also I had a rectifier that one of the cables had basically corroded off, a simple pull broke the one or two remaining strands.
also i did test that choke solenoid and it did not respond, maybe because of rectifier but i do not know for sure.

i am going to replace rectifier, choke solenoid and maybe starter solenoid.

In other news before the rectifier went sideways i managed to find a like new starter here locally but it was spinning up then it would lock up totally and got so hot when i tried to take the wing nuts off my battery it left a blister on my thumb.

I am hoping that a new starter solenoid helps resolve this.

I am learning a lot and will knwo this engine pretty well soon.

 

[racerone]

Rectifier has nothing to do with the choke.-----Check gear oil.-----Post compression test values here.-----Do not spend any hard earned money until after you do a complete evaluation of this motor.----Install a new water pump impeller before you launch the boat !----Test you overheat warning horn.

 

[Crosbyman]

also i did test that choke solenoid and it did not respond because...?

1. the inside magnet coil was tested open with a ohmeter
2. the solenoid was not grounded properly
3. the solenoid was mecanically impaired ...as in stuck

btw rectifiers (4 way diode bridge) are dirt cheapon amazon. YOu could get a 25-50 amp one and use it for testing and then if you must ...buy a 40-70$ one
yellows go on AC pins

Amazon.com