Tracing ing electric on 1978 1150 mercury

"recently purchased a boat wit

"recently purchased a boat with a 1978 1150 inline 6 115 hp hasn.t been run in about 3 years i havn't tried strrating it yet. just thru checking compression all cyls run about 120 except #2 cyl is about 10 psi lower. my question is about the ing circuit. i have power showing to and from ing switch back to the switch box on the white wire, should my test lite show power on the green wire to the coil at this point? jimg984 in north carolina"

"No, there should not be power

"No, there should not be power on the green wire with the motor not running. Since its been sitting for a few years there are some other things that should be done. Change the oil in the LU and replace the impeller (it can dry rot from sitting). Check all the other hoses for cracks. You most likely will have to rebuild the fuel pump and carbs as fuel can gel from sitting and clog things up. Those old towers of power are good motors and there are a lot of them still out there running strong."

"thank you!! for taking the t

"thank you!! for taking the time to reply and give me good information also I need to know if any of the wires, brown, black, and white from the switch box to the distributor show power with the engine not running with the switch key turned on. I purchased a Seloc repair manual that has good wiring diagrams and other good info.. just wanting to go slow and easy on getting this TOWER of POWER going.

what do think about #2 cyl being 10 psi lower than the other cyls

jimg984"

"James
IBNFISHN is right on t

"James
IBNFISHN is right on the money. I own a 115 merc.
Fuel Pump, Carbs And Impeller. Top carb could be starved for fuel. Impeler is just as important, You don't want to over heat and snap a ring.
The Slammmer"

"James, Here is the diagnosti

"James, Here is the diagnostic procedure for that distributor ignition. Courtesy of Clams Canino. You need to have +12V on both red (always hot) and the white (ignition on)wires on the switchbox. This test assumes the ignition coil is good.

Disconnect wiring harness, remove the three dist leads from the switchbox. jumper the white and brown distributor connections on the switchbox together. reconnect wiring harness and turn key to on position. Now jumper black switchbox terminal to ground and ignition coil should fire each time you touch ground.

If it fires each time, switchbox is good, and distributor trigger may be bad."

the part of your information t

the part of your information that isn't clear to me is when jumpering brown and white together is it the wires or the terminals


ths
james