1985 Mercury Black Max 150 XR2

[79XLT]

I have not received my service manual yet, so I am looking for a little help. I am wondering what the "module" is that is on the top port side of the motor behind the flywheel. It has three wires coming out of it. Part number is 93772a2. It is NLA from Mercury, mine is disconnected and so am thinking this is nothing critical to running? Thank you for your help.

1985 Mercury 150 XR2, ser. no. A139148

 

[superbang]

Re: 1985 Mercury Black Max 150 XR2

Try taking a couple shots of what you are talking about and post it up. That may help you get some feedback.

GL!

 

[79XLT]

Re: 1985 Mercury Black Max 150 XR2

Thank you for the reply. I will try and post a picture when I get home this weekend.

 

[Faztbullet]

Re: 1985 Mercury Black Max 150 XR2

It is a combination low speed/high speed spark advance module. Take it off and throw it away as it can damage engine if defective.

 

[j_martin]

Re: 1985 Mercury Black Max 150 XR2

It is a combination low speed/high speed spark advance module. Take it off and throw it away as it can damage engine if defective.

When you do, do a link n sync. Your WOT timing is probably at 19* now, and without the module should be at 23*.

Other than that, the module advances the timing a bit if idle speed goes below a certain point, and it advances the timing 4 degrees at 5000 rpm, and maybe retards it at 6 degrees at 5500. If it shorts out at WOT, it'll grenade yer powerhead before you can figure out what the strange noise (preignition) is.

hope it helps
John

 

[79XLT]

Re: 1985 Mercury Black Max 150 XR2

Okay, so just to be sure I understand - my module is already disconnected(bought it that way). What do I need to set the timing at at WOT?