Mercury 90hp no spark?

[wilson750]

I recently received a 90 hp mercury, 3 cylinder, year 88. I don't know much about the motor except it was clean and stored indoors for years. Has good compression on all 3. So today I plugged in the harness to see if it got spark. And it did not. I hooked the two yellow wires together to bypass the neutral switch and still nothing. The only wire not hooked to anything Is a brown wire. Anyone know what the brown wire gets connected too? I was thinking the alarm?
If anyone has some input on what wires need to be hooked up to receive spark please help me out.

 

[Texasmark]

If no answer answer yourself with the word "Bump". Like my reply is going to do, it will put your question back first in line where it can get more visibility. There are folks on here that can answer that question. I can't as my experience is with later engines and no brown wires were used.......tan and tan/light blue stripe (over temp and low oil alarm signals) but no brown.

 

[GA_Boater]

What two yellow wires? Where is the brown wire - At the end of the harness or inside the cowl?

The only yellow wires inside the cowl are the stator wires to the rectifier.

Wiring diagrams start on this page - http://boatinfo.no/lib/mercury/manuals/70-75-80-90-100-115.html#/72

 

[wrench 3]

The simple answer to"what wires need to be hooked up to receive spark" is none. Providing every thing is hooked up on the engine itself.You just have to have the battery hooked up to crank the engine over. Powering the yellow wire will activate the starter solenoid.
You have to ground the black with yellow wire to stop the engine.
Your disconnected brown wire could be a problem since it runs between the trigger and the switch box. (both ignition components) See the wiring diagram on page 72 at the link GA Boater gave you.

BTW GA' for some reason links to boatinfo won't take you to the page only to the front of the manual.

 

[GA_Boater]

Just tried with my Alt-Mod user name and it did take me to page 72. :noidea: why you didn't get the page, Wrench. Darned computers!

 

[wrench 3]

Just tried with my Alt-Mod user name and it did take me to page 72. :noidea: why you didn't get the page, Wrench. Darned computers!

Every time I post one of their links I try it to make sure it works and it never goes to the page. Maybe I just don't rate?

 

[GA_Boater]

Every time I post one of their links I try it to make sure it works and it never goes to the page. Maybe I just don't rate?

On a smartphone? They seem to have special problems with this version of VBulletin which IT is trying to fix.

 

[wilson750]

The simple answer to"what wires need to be hooked up to receive spark" is none. Providing every thing is hooked up on the engine itself.You just have to have the battery hooked up to crank the engine over. Powering the yellow wire will activate the starter solenoid.
You have to ground the black with yellow wire to stop the engine.
Your disconnected brown wire could be a problem since it runs between the trigger and the switch box. (both ignition components) See the wiring diagram on page 72 at the link GA Boater gave you.

BTW GA' for some reason links to boatinfo won't take you to the page only to the front of the manual.

The Brown wire Is coming out of the harness.I will look at the diagram and see if taht is the problem. Thanks for your help!!

 

[wrench 3]

I would expect that the brown wire that I'm talking about would be coming out of a small four wire harness along with a white, purple and a white/black.
A minor edit on my last post to you. The wire to activate the starter solenoid should read as the yellow/red wire.

 

[wrench 3]

On a smartphone? They seem to have special problems with this version of VBulletin which IT is trying to fix.

At the risk of hijacking the thread I'll give a short reply. I'm using a lap top computer.

 

[wilson750]

Ok Well lets bump this to the top. I was told if I disconnect the wire harness and jump the starter it should have spark. Well it still doesnt. So I assume it's either the the trigger or stator?

Can anyone give some info on testing them? I did a search and came up empty.

 

[goldstem]

I believe the brown wire is for the tach. do not hook anything to it

 

[wilson750]

Thanks, I'm looking on how to test trigger or stator if that is true when you unplug the harness and jump starter that the motor should get spark.

 

[wrench 3]

Test procedures start on page 21 of the link that GA Boater gave you.