Help! need info on mercury motor

[Kfisch37]

I am new to the boating world and have very little knowledge on boats!
First, I have a mercury 115 HP motor on my pontoon. No idea what year it is, if it's 2, 4 or 6 cycle, or what kind of fuel/oil to put in it. Any ideas or information is greatly appreciated!

 

[JB]

Re: Help! need info on mercury motor

Howdy, Kfisch.

Welcome to iboats. :welcome:

Some of our mercsperts might recognize it, but if you can give us the serial number they can probably tell you all there is to know except maybe the name of the tech who QCed it.

 

[Chris1956]

Re: Help! need info on mercury motor

Remove the wrap cowl and count the spark plugs. Looks like an inline 6, 2 cycle motor from the 70 or early 80s. Normally you would run a 50::1 gas/oil mix for fuel

 

[Kfisch37]

Re: Help! need info on mercury motor

There are 6 connections on the back side, i believe the spark plugs. I can't find a serial number yet, could be on the inside that I can't get to yet. Thanks for your help so far though!

 

[Chris1956]

Re: Help! need info on mercury motor

Serial number would normally be between the transom clamps

 

[calvinator]

Re: Help! need info on mercury motor

Serial # will tell the exact year, but that looks like a 1975 or 1976 Merc 1150. I have the 1500 motor with the same style of cowling - mine is a 1975.

That is a 2 stroke, 6 cylinder motor.
50:1 gasil mix.
Very good motor.


Sounds like you are ramping up your knowledge on your motor. Read up on your water pump impeller, what it does, how to tell it is working, etc. Water pump keeps your engine cooled with lake water. Overheated engines get damaged and the repair cost for these old motors will most likely exceed the value....

 

[Kfisch37]

Re: Help! need info on mercury motor

Serial number is 3947755.
Motor isn't getting any spark. Turns over but no spark to the motor. Any ideas?

 

[Chris1956]

Re: Help! need info on mercury motor

OK< That serial number places it as a 1974. It should have a battery-powered CDI ignition with a distributor. There is a CDIElectronics website with a troubleshooting test,

That motor needs +12VDC on both the red wire on the switchbox and the adjacent white wire on the switchbox to have spark.

 

[Kfisch37]

Re: Help! need info on mercury motor

They said the red and white have power. Unsure what the brown wire is for though

 

[Chris1956]

Re: Help! need info on mercury motor

There may be two brown wires on the switchbox. You may have one next to the red wire for the tach signal. The other one is a distributor trigger wire.

Go to the CDIelectonics web site and run the troubleshooting test for the Mercury battery powered CDI ignition.