84' 90hp johnson won't start

[donson65]

First off what a great forum ! Thanks for being here. now on to my dilemma.

I have a 1984 Johnson 90hp (J90mlcrd) that I can't get any spark to the plugs.
It has been some time since the motor has ran (1.5 yrs ?). I have fresh fuel, plugs and new battery, of course all that except the battery is a mute point without fire. I need help, all four coils couldn't be bad at one time could they ?
Or maybe the power packs (x2) are both bad at the same time
I'm not really sure which direction to go and would greatly appreciate your words of knowledge.
This motor and boat (17ft alumacraft super bandit) belonged to my father when I was a jr. in High school (long time ago) and I bought it from my cousin who didn't take care of it so I'm restoring it to fishing condition.

Thanks,
Don

 

[jtexas]

Re: 84' 90hp johnson won't start

welcome to iboats!

first rule out the kill circuit: disconnect the red main wiring harness plug and check for spark by jumping the solenoid. best to have all plug wires off & grounded; if she starts like this there's no way to shut her off except manual flooding via the primer. Got spark in this manner, troubleshoot keyswitch, emergency kill switch, wiring harness (black/yellow wire).

battery is hardly a mute point considering that if ya don't spin her fast enough, she can't make any spark.

 

[HighTrim]

Re: 84' 90hp johnson won't start

this FAQ thread should also help you out

http://forums.iboats.com/showthread.php?t=158071

 

[donson65]

Re: 84' 90hp johnson won't start

I will attempt to check these things out this week and let you know what I find. Thanks

 

[donson65]

Re: 84' 90hp johnson won't start

Sorry for taking so long to give some feedback but thats work for ya.
Well guess what I dicovered ! A naked kill switch on the throttle control upfront. now the hunt is on to find it. I had it.
If i'm unable to locate it (3 children) can I simply go to a local marina store and pick up one that fits it and what can I do until then ?
Thx
Don

 

[jtexas]

Re: 84' 90hp johnson won't start

sorry, not familiar with the terminology "naked kill switch" (although I do understand the concept of "naked" ) - the kill switch is normally open, when closed it connects the black/yellow kill wire to ground. So, you can see, the kill switch is "essential safety equipment" (esp. with 3 small children aboard), but not essential to operation of the engine...........

 

[donson65]

Re: 84' 90hp johnson won't start

Can I go by a Marina and purchase the device that fits over the kill switch and depresses it

 

[jtexas]

Re: 84' 90hp johnson won't start

ah, I see........here: http://epc.brp.com/default.aspx?brands=ej&lang=E you will find your engine schematics and part lists (drill down to your year/model - it says evinrude but johnsons are there too), hopefully that part will be pictured and you can get the part number to aid in your search. from www.johnson.com you can get a list of parts dealers in your area. I don't know if any aftermarket parts are compatible.

meanwhile you can just disconnect the switch for troubleshooting - that won't affect the running of the motor. and/or replace it with an aftermarket emergency cutoff switch from basspro, academy, cabelas, etc.

 

[donson65]

Re: 84' 90hp johnson won't start

I actually found the cap & lanyard that goes to the remote control throttle unit kill switch. Attached it and the jhonson cranked right up, well with a little persuasion. Thanks for all the advice, I'm positive I'll have more questions later.
More prep work for today but tomorrow we'll see how she runs on the water.

Don

 

[donson65]

Re: 84' 90hp johnson won't start

Ok, time for an update.

Motor would run as long as I would squeeze the fuel line bulb every little bit but would eventually die out when I stopped, so that meant fuel pump is bad or going bad and it took me looking at a parts schematic to figure out the VRO and Fuel pump are together working off of manifold pressure. Well I new the VRO wasn't functioning from previous owner so that probably meant neither was the F.P. So today I installed a 12v inline fuel pump low pressure. Oh how wonderful to have a great fuel flow. Oh this boat will scat not that I want to go fast but it is fast for what it is, moving on.

I was adjusted the idle, got it to where I wanted it, by ear that is. I currently don't have an rpm gauge installed. But when I place the engine cover back on the engine would die out during idle, hhhmmmm not enough air ? What do you guys think and what is your advice on setting the idle?

Thanks again for all your help and awsome advice

Don

 

[donson65]

Re: 84' 90hp johnson won't start

Ok, time for an update.

Motor would run as long as I would squeeze the fuel line bulb every little bit but would eventually die out when I stopped, so that meant fuel pump is bad or going bad and it took me looking at a parts schematic to figure out the VRO and Fuel pump are together working off of manifold pressure. Well I new the VRO wasn't functioning from previous owner so that probably meant neither was the F.P. So today I installed a 12v inline fuel pump low pressure. Oh how wonderful to have a great fuel flow. Oh this boat will scat not that I want to go fast but it is fast for what it is, moving on.

I was adjusted the idle, got it to where I wanted it, by ear that is. I currently don't have an rpm gauge installed. But when I place the engine cover back on the engine would die out during idle, hhhmmmm not enough air ? What do you guys think and what is your advice on setting the idle?

Thanks again for all your help and awsome advice

Don

I'm posting this quote from my last post in hopes of a response the resident guru's out their. Fuel flow isn't an issue but the motor continues to die out when I put the cover on it. I really just don't know what to do next. I would think it has plenty of air. In some crazy way could the adjustment I made to the idle (using the idle adjustment screw) somehow adversely affecting it, or could the motor shroud be touching something it shouldn't. I just don't know and I need yuz guyz help please

Don

 

[jtexas]

Re: 84' 90hp johnson won't start

you haven't dropped the lower unit recently, have you? for a water pump change or something? if so, did you by any chance forget to put the o-ring back on the driveshaft, up under the splines?

You have to set the idle with the motor in gear and lower unit submerged - I've done it tied to the dock and on the trailer on the ramp. I guess without a tach, you just have to make it "feel good" enough to idle in gear but not to damage the gears.