1977 75hp evinrude 75743s misfire running rough.

[racerone]

My tester would show 145 /150 on a good one of those.----Might try another test gauge.

 

[Landonsideways]

I know the manual says to warm it up for like 15 min and then test it but was unable to at the moment that I loaned the tester. It was cold when I tested it and suspect that might make 5 or 10 psi difference. I've been having to use a regular gas can for my fuel tank and it rained and got water in it and didn't want to put that gas in my motor. Am awaiting a new portable marine tank from eBay. That tank was just so I could see if and how it ran after I got it. Do you have any idea how much if any difference it makes cold to hot?

 

[F_R]

In your original post, you mentioned the kill wire. It is a real possibility that it could be causing some problems. Not just in the picture view, but anywhere along it's route to the ignition switch---or even in the switch itself. That wire can arc out through moisture, dirt, whatever. If it does arc, you will get a misfire, or possibly even quit running.

 

[Landonsideways]

Well I'm supose to get the carb kit and impeller any day, going to get those parts on and if problem persists I will fix that wire, and check to make sure spark is jumping a half inch and go from there. I did have to rewire the whole ignition, had to put 2 controls together to one good one. Went from a switch choke to a push to choke. I think I got everything wired right. I guess it makes sense if a wire is getting grounded anywhere along the way it could be creating problems. Let me get these parts on and see where I am. Thanks for the continuous replys. I learn from you guys. Much appreciated.... I'll take some pics of the carb rebuild. Pictures make everything more interesting. At least it does for me when I'm reading someone's post. Might share a YouTube link of the motor running when I get her back 2get her and going.

 

[Landonsideways]

Well I'm halfway through my carb rebuild and am finding the seat screw for the needle seems to be a size bigger than the existing one. Should I be concerned? Also look at all the crap in the bottom carb, the middle one was clean. Getting ready to do top one but would like to make sure evinrude isn't calling for a size bigger than what I got in my kit. Seems like I remember reading about something like that. Anyone know what they would do?

 

[Landonsideways]

I had a surprise. Got lower unit off and my key and housing don't fit on water pump. Can someone help me figure out what I need to do. Supposed to be a 75 75hp evinrude 1977. Don't know what to do.... Plz help

 

[Landonsideways]

Thanks everyone. Cleaned carbs and kit put in and runs great.... One of the floats was way out of wack and the seats that came with the kit was a size smaller.