1985 Mecury 75hp, kill circuit

[N1265]

Hi Guys,

No spark on my 1985 Mecury OB. I have tested the tilt switch ( ok ) fully charged the battery and looked at the wiring for anything obvious ( nothing apparent )

Before tearing into the quicksilver , witch I am not exactly sure how it comes apart, I wanted to test the kill circuit by disconnecting it. I removed the black and yellow leads that are staked at the engine side but still did not get any spark, but I am not 100% sure if this is the correct method to test this circuit.

What is the correct procedure to ruel out the kill circuit is keeping the motor from running ?

Also, what is that hole in front of the quicksilver for ?

Many Thanks,

 

[Faztbullet]

Disconnect the blk yell wire from connection, make sure motor is spinning fast. hole is for harness to wire in tach,trim gauge

 

[frustratedboater]

Got a meter?

 

[N1265]

Both wires were disconnected from block and each other, motor seems to be spinning fast enough to me and still no spark.

I do have a volt meter. what is the next step to figure out a no spark condition

 

[Faztbullet]

Check your voltage on stator

 

[N1265]

tried to find a you tube video on how to do this but could not find one that was mecury specfic, do you have to pull the stator on this motor to test it ?

 

[N1265]

Can anybody tell me the thread size of the flywheel puller so I can get the right one ? (1985 75 Hp)

 

[Faztbullet]

You do not have to remove stator to test it...Go here and read

Page 24 - Mercury Mariner outboard ignition troubleshooter

Testing 1978-97 four cylinder Mercury Mariner engines using a single switch box and four ignition coils

www.outboardignition.com

 

[N1265]

Hi Guys,
Can anybody tell me the part numbers for a Trigger and the Electrical box on a 1985 75hp Mercury OB ?

 

[Chris1956]

You can look them up on crowleymarine. The switchbox and trigger should be in wide use so you can get one at many places on the web.

 

[racerone]

Parts are expensive !----What testing was done on trigger unit ?----I would start with getting battery load tested. ---Often a free service at some battery retailers.-----And I would take starter apart for ohm check on armature.-----Should show infinity.-----Possibly new brushes.-----But if beer tokens are not an issue go ahead and order a new switch box and trigger.

 

[N1265]

Parts are expensive !----What testing was done on trigger unit ?----I would start with getting battery load tested. ---Often a free service at some battery retailers.-----And I would take starter apart for ohm check on armature.-----Should show infinity.-----Possibly new brushes.-----But if beer tokens are not an issue go ahead and order a new switch box and trigger.

I do not know what testing was done on trigger, I had to have a mobil mechanic come out to diagnose the problem because I could not find anything wrong. He told me the flywheel, magnets and wireing was good but the trigger was bad. He said he could not diagnose further until trigger was replaced. he said the switch box is usually what goes but he could not diagnose it with a bad trigger.