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1972 85hp outboard problem

J

Joshua Rogel

New member
Hello all,

I have a 1972 Johnson 85hp outboard. I have never had any success in getting this motor to idle correctly. I have rebuilt the carbs, checked compression, replaced plug wires. I have been eyeballing the points, they don't look like they are in the best of condition.

My question is, is their an ignition system upgrade for this motor? Point run 65$ each. Kinda want to move to more of a reliable system, if ya know what I mean.

Thanks in advance..
 
Set the points at 0.010"------------clean the distributor cap and rotor.-------------Points on that motor should last the life of the motor.------Replace the anti-reversing spring.
 
The carbs have been rebuilt. If thats what you mean. I have points and anti reverse spring on order. See if this helps.

Also, I noticed that when in neutral at the controals, the lower unit is actually in drive. I did recently drop the lower unit and reconnected that cables. I didt swap the cable then the motor started acting funny and wouldnt go into gear.
 
Motor only shifts from drive to nuetral when it is TURNING.-------------In other words when the motor is stopped it should be in forward.-------------------Motor running and 12 volts applied to the green puts it in nuetral.-----------12 volts applied to green and blue gets you reverse.
 
Re: 1972 85hp outboard problem: UPDATE With video

Here is an update on the issue.
Points have been replaced. New wires on the points. the old ones that looked bad. They have been gapped to .010. New anti rotation spring. here is a vid of here running.

 
It doesn't look or sound bad to me. The poster who mentioned the decarb is talking about the seafoam treatment.
cheap and worth a try.
How does it perform on the water?
 
I will give the sea foam a shot. Do you just dump it into the carbs or do you hook up to fuel lines?

Also, i performed my own compression test. The guy who I got the boat from said it was good. Just going off him. Anyways, the compression is at 40 psi on each cylinder. Is this good?

Havent taken her out to the water since the points change.
 
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40 PSI on each cylinder is way to low.-------------My guess is that the gauge you are using is way out of calibration.-------------Low speed mixture screw turned in gently seated and then backed out 7/8 turn for initial start-up ???
 
sorry , my mistake .------- the 72 85 HP was one of the first to be equipped with fixed low speed jets.--No adjustment other than opening the up 0.002 " or so.
 
try squirting a bit of oil down the bores,then wind her over a few times,then do another compression check.see if it goes up.you should have at least about 90 psi
 
I tried the sea foam deal. I gal of gas and a bottle of sea foam. Ran it for about 10-15 min. Smoked a little. Didn't seem to change anything. Returned back to normal and ran for a bit.


Everytime I start her up and let her run. She smokes like a chimey.
 
With one gauge showing 40psig and another gauge showing 35psig on compression I would suspect worn rings. As budgie14 suggested, squirt some oil in each sparkplug hole and run another compression check. If the pressure goes up the piston rings will need to be replaced.
 
Assuming your talking about using WD40? If that doesnt raise the psi, any other ideals on what causes that?

On another note, I did replace the two inner/outer gaskets for the exhaust cover.
 
Went out and got a new compression gauge, compression test reads 120psi on each cylinder. Got her running a little better. It seems like cylinder #4 has a cough coming out the the carb. Any ideals on this? when it coughs it bogs down the motor.
 
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