1976 Johnson 85HP cannot start

dmcneill3 · Jul 11, 2011

Fuel appears fine and good flow
How do I verify that I have good spark?
What does the Power Pack do and how do you know it is working?

dmcneill3 · Jul 11, 2011

Re: 1976 Johnson 85HP cannot start

Does anyone know if there is an online manual for this engine available?

Daviet · Jul 11, 2011

Re: 1976 Johnson 85HP cannot start

You should start with a spark and compression test. The spark should jump a 7/16" air gap. check with your local auto parts store, they should sell some type of an adjustable spark checker. Compression should be some where around 100-125 psi and within 10% of each other.
About the only place to find a factory manual is on e-bay or google Ken Cook, he sells factory manuals. Make sure and order by using your model number for thecorrect manual.

dmcneill3 · Jul 11, 2011

Re: 1976 Johnson 85HP cannot start

I have checked the compression and all 4 cylinders are good. If I had a bad kill circuit on the power pack is that the black and yellow wire and if I took that off for testing purposes would that hurt anything?

Daviet · Jul 11, 2011

Re: 1976 Johnson 85HP cannot start

Yes, remove the black/yellow wire to test the system. If the engine should start you will have to choke the engine off.

dmcneill3 · Jul 11, 2011

Re: 1976 Johnson 85HP cannot start

I cannot just touch the black/yellow wire to the terminal with the switch off to kill engine

Daviet · Jul 11, 2011

Re: 1976 Johnson 85HP cannot start

Sorry, yes you can, I was confusing you with another problem.

dmcneill3 · Jul 11, 2011

Re: 1976 Johnson 85HP cannot start

Thanks for your help

dmcneill3 · Jul 11, 2011

Re: 1976 Johnson 85HP cannot start

So I tried to start the engine with the kill wire on the powerpack removed no luck. I bought a sparkplug inline wire tester and tesed all plugs and no spark to any of them. What should try next? By the way this engine ran great last year.

dmcneill3 · Jul 11, 2011

Re: 1976 Johnson 85HP cannot start

I also noticed that there was spark when the spark plug was out but not when screwed in. I also removed the two yellow wired of the rectifier and tested but no spark. The fact that there is spark with the plug removed I was reading suggested that the battery might not be charged which it is, there might be a bad connection from the battery to the engine, the RPMs are not high enough to generate the spark do to possible starter issue or something internally in the engine.

How can I test the RPM's?

dmcneill3 · Jul 11, 2011

Re: 1976 Johnson 85HP cannot start

I found that the battery cables were corroded just enough to not get a fast enough RPM. Once I cleaned them then I could get the engine started. But now I have a problem with the engine idling out of control. Is there something that would cause this?

emdsapmgr · Jul 12, 2011

Re: 1976 Johnson 85HP cannot start

The starter on that engine must rotate the engine approx 200-250 rpm in order to fire the ignition system. Good find on your part. Does the engine race when when the boat is floating normally in the water? Or when sitting on the trailer? Make sure the spark advance lever is moving easily and that the spark lever is moving the timer base fully rearward when the throttle handle is in neutral.

dmcneill3 · Jul 12, 2011

Re: 1976 Johnson 85HP cannot start

Sorry to be such an idiot here but what does the spark advance lever and the timer base look like.
All of this testing so far has been on the trailor. Don't want to go to water until I know it will not break down on me.

emdsapmgr · Jul 12, 2011

Re: 1976 Johnson 85HP cannot start

You can look at the factory exploded parts diagrams online at: epc.brp.com. They will help you see the parts in question. An original factory service manual can be obtained from: outboardbooks.com.

dmcneill3 · Jul 12, 2011

Re: 1976 Johnson 85HP cannot start

Thanks

1976 Johnson 85HP cannot start

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