'85 Johnson 30hp wont start, please help!

[Bradley_G]

I recently bought a boat with a J30elcoa '85 30hp Johnson outboard. When testing the motor it ran fine while I tested it. I replaced the impeller, spark plugs and lower unit oil, and took it out today. Idled fine, and then I started to hear a squealing noise soudned like it was coming from the ignition/gear shift.... I turned off the engine and started again after a few mins, noise was gone and seemed to run fine, then after I got to the wake zone I opened it up a little bit and it seemed to be holding back, then after about 2 minutes the engine slowly faded out, as if the gas was running out, but never sputtered, and then it died. there was a bit of smoke, seemed to be electrical by the smell and i took off the cover to try and see if anything was melted but everything seemed to look fine, but I dont really know what all I was looking for.

Anyways I couldnt start it again and had to use the trolling motor to get back.

Any troubleshooting tips would be appreciated, Im certainly a rookie when it comes to engine repair but am capable of handling repairs when I have an idea what to do......

 

[matt9923]

Re: '85 Johnson 30hp wont start, please help!

Its hard to tell. Can you get it running out of the water on the muffs? Try starting it and look and see if anything smoke or looks cooked.
someone else probably has a better idea.
Matt

 

[Bradley_G]

Re: '85 Johnson 30hp wont start, please help!

havent tried it yet but will tomorrow.. Does not appear to have anything cooked.

 

[jbjennings]

Re: '85 Johnson 30hp wont start, please help!

Curious,
After you changed the water pump impeller did you still have a good tell -tale stream coming out?
I'm just worried after you changed the impeller you might have missed getting the water tube in the grommet and burned the powerhead up due to lack of cooling water.
What you described sounds like an overheat to me.
Hopefully, that's not the case!
JBJ

 

[Mas]

Re: '85 Johnson 30hp wont start, please help!

May have a pinched water tube grommet upon reinstall. Definitely sounds like you overheated!

MAS

 

[tashasdaddy]

Re: '85 Johnson 30hp wont start, please help!

agree. check grommet, impeller key. check compression and spark also.

 

[Bradley_G]

Photo Attached......

Photo Attached......

I didnt check the stream after install, and couldnt get it started today w/ the muffs. notice two cinged wires, one black w/ yellow tracer (kill switch?) and one brown wire that goes into the engine. perhaps this happened because of overheating, if so, what all damage might I have done?

Pulled out the plugs to check for spark (which were brand new) and noticed that there was debris (carbon?) stuck on them and on one bridging the gap. I cleaned them up and tested and confirmed there is spark.

Also, when attmepting to start the engine, sometimes the starter cog (whatever its called) stays engaged withe the engine cog (i think one of those is a flyweel?) and sometimes it goes down, could this be an issue as well?

 

[Bradley_G]

Re: '85 Johnson 30hp wont start, please help!

bump

 

[Bradley_G]

Re: '85 Johnson 30hp wont start, please help!

so I am guessing by what I have managed to read that the squealing was a overheat alarm, but I had no clue as I dont have gauges and didnt look for a tell tale... this is my first boat so I'm definately paying that price.

My question now, what will I need to do to check the damage, repair and get this thing running again?

 

[samo_ott]

Re: '85 Johnson 30hp wont start, please help!

Sounds like an overheat to me also. I would check the compression first. It's one of the biggest indicators as to the internal condition. Then what happens next depends on the #'s. You might need to pull the head.

 

[Bradley_G]

Re: '85 Johnson 30hp wont start, please help!

I will pickup a compression tester tomorrow morning and see about checking it.

 

[Mas]

Re: '85 Johnson 30hp wont start, please help!

You want the compression numbers to be even...very uneven numbers means trouble. I'm not sure what standard compression is for your motor, but my '94 20 hp I've got 125 psi in each hole.

MAS

 

[Bradley_G]

Re: '85 Johnson 30hp wont start, please help!

couldn't pick up the compression meter yesterday, will have to pick it up today...

 

[Bradley_G]

Re: '85 Johnson 30hp wont start, please help!

can anyone help me identify the brown wire that goes into the head? (pictured above) It has the insulation melted and I am assuming it is grounding out, which I assume that I will need to replace. Is this the heat sensor? is there a way to bypass this to test if it is the reason that the engine is not starting? once it stops raining I plan to do a compression test.

 

[ezeke]

Re: '85 Johnson 30hp wont start, please help!

That is the tan wire for the overheat switch in the cylinder head. The wire should have a quick disconnect several inches out from the head. That wire is a simple ground for the horn which is activated when the temperature switch recognizes an overheat condition.

There is normally not enough power in the tan wire to burn the insulation before the horn, so look for external causes of the overheat, or a short somewhere in the harness.

You might want to disconnect the black and yellow kill wire temporarily and try to start the motor. Be prepared to choke the engine or disconnect the fuel to stop it if the engine starts.

 

[Bradley_G]

Re: '85 Johnson 30hp wont start, please help!

I think the heat of the motor melted the wires (both kill and brown wire into head) they melted where there was contact with the block. Looks like the weather wont hold up for me today so I'll have to attack this tomorrow.

 

[Bradley_G]

Re: '85 Johnson 30hp wont start, please help!

ran the compression test, 30psi in each cylinder. Im assuming that is terrible news.
I did remove the lower end unit and reinstall the water tube correctly, it was misaligned.

Now that I know that I dont have the compression, what's next?

 

[samo_ott]

Re: '85 Johnson 30hp wont start, please help!

Ooh. That's real bad. are you sure you did it right? Was that the highest reading you got? were you using electric start or pull start?

You best hope is that it's the head gasket, the worst case is rings, pistons, etc...

 

[Bradley_G]

Re: '85 Johnson 30hp wont start, please help!

this is what I did:

Removed both spark plug wires, removed top spark plug and attached compression tool.
Choked and cranked from electric starter and watched until gauge reached maximum psi (30) (3-7 seconds perhaps). tried to raise fast idle lever and no increase/decrease in PSI.

removed lower spark plug and replaced upper, repeated above process.

I also tried the test with both spark plugs removed, and compression tool in each cylinder separately with same results. only 30psi compression.

I also disconnected the brown (or tan?) wire that enters the powerhead at the quick disconnect point to do so.

If by chance could the kill switch have prohibited the motor from turning at its proper compression? is there a way to bypass the kill switch feature? it appears to enter a connector joined with multiple wires, so I did not think to disconnect it.

 

[jbjennings]

Re: '85 Johnson 30hp wont start, please help!

I find it hard to believe that it's that low, even though it sounds like you really got it awful hot. The next step is no doubt to remove the head and take a look. I'd also remove the bypass covers and look at the rings. You might push on 'em and see if they have any spring left and see if they're stuck in the grooves. If you truly have 30lbs. in each cylinder that powerhead is toast. BUt hopefully it's just a head gasket problem. With only 30lbs., you should really see some obvious problems when you pull the head. If you see deep scoring and burnt pistons, you're ready for a new used powerhead. If not, you may be able to refinish the head and use a new gasket.
I'm hoping you find the latter! You never know until you pull the head.
Got my fingers and toes crossed for you,:redface:
JBJ