1977 Mercury 1500, Need Help Bad

[Blevins Gap Outdoors]

Ok guys, I have a 1977 Mercury 1500 inline six that will start at home every time I try it but will not run when I get to the lake or will start and then stop like you turn the key off. Some times it will start and when I put it in gear it like I turned the key off. It is driving me crazy...

I have put a new trigger in it and new internal wiring harness in it plus changed out the ignition switch. I disconnected the mercury tilt switch. It also has a new stator.

Can anyone give me some ideas what to check next. Anything will help.

Thanks

 

[bktheking]

Re: 1977 Mercury 1500, Need Help Bad

Any water on the spark plugs after it' been run in the lake?

 

[Faztbullet]

Re: 1977 Mercury 1500, Need Help Bad

Sounds like your dropping voltage to switchbox, next time you go to lake take a test light and place it on white wire of box. When engine wont start or quits see if light is weak or off. If off you have a break in wiring(loose/bad pin in side connector) or if still on possible a bad switch box or defective trigger..

 

[Blevins Gap Outdoors]

Re: 1977 Mercury 1500, Need Help Bad

There is no water on plugs. As far a wiring problem goes, you said if the tester light is weak or off you have a break in wiring(loose/bad pin in side connector). Do you mean the connector on the switchbox. (white wire)

 

[Faztbullet]

Re: 1977 Mercury 1500, Need Help Bad

Your harness where it plugs into side of engine...

 

[Blevins Gap Outdoors]

Re: 1977 Mercury 1500, Need Help Bad

Your harness where it plugs into side of engine...

Got you, I have replaced the internal wiring harness so I will check the harness from the control.