1977 75hp evinrude 75743s misfire running rough.

[Landonsideways]

Hi. I am in the middle of trying to get this engine I just got, for 250$, ready to take fishing this spring. Have checked spark and is good in all 3. Will be checking compression this Friday when I get a gauge, payday. I t started up the second turn of the key, so I'm expecting it to be fairly acceptable. It did run, which was happy with that seems how I got it pretty cheap. Guy said he was pulling some skiers last year and started acting weird, so got a 115. Seemed to be getting plenty fuel, almost like it was too rich. Anyways, is it possible that the ground wire(going into the power pack) could be doing some sneaky stuff? I could see where that might affect some things if that wire is frayed in one part and open to the elements and not at full strength so to speak. Let me know your thoughts plz. Maybe some recommendations on what else I should be looking at too. Thanks for your time guys....

Tried uploading an attachment picture file, but didn't work.

 

[Landonsideways]

By the way, for anyone reading this needing help, buy the real oem manual and not the cheap $9.00 one I got as a pdf

 

[oldboat1]

When you measured spark, what did you get?

Sounds like the boat didn't come with it, and maybe an old built in tank and fuel -- can be a good thing. You will want to run with fresh fuel using a 50:1 mix. For testing, running in a large barrel would be better than on muffs (lake is best). Can't goose it in the yard, but could get it up to temp (around 140F, not over 160), then put on a pair of gloves and pull off plug boots one at a time. Loss in rpms is good -- no change can mean that the plug isn't firing. (If you have a timing gun, you can check that way -- just clamp on wires and check for flash.) Make sure it's pumping water, and doesn't overheat.

Frayed wiring sure can be the problem, if that is what you are finding. (might be able to borrow a compression tester from an auto parts store, btw.)

Possible the motor just didn't have the ponies your bud needed -- might have a super deal there.

 

[F_R]

Can be one of several possibilities. Spark, Spark plug, dirty carburetor, ruptured fuel pump diaphragm, compression (engine damage), water ingestion into a cylinder, busted reed, to name just a few. In other words, you have some troubleshooting to do.

 

[Landonsideways]

Water injection to the cylinder can make it run rough? I knew it could make it overheat. It has a telltail installed on it and the stream was there, but not strong, I pulled the engine warm up lever a little bit and the stream almost went away completely so I put back down. Plan on new impeller, maybe whole pump assembly. New spark plugs on it before I started thread so should be good there. Will get gap tester and do the formal test instead of holding to ground and do compression test and report back. How about that... Thanks guys

 

[Landonsideways]

And yeah, I'm restoring a 1977 glastron 15' bass boat I got for 250 and this motor for 250. Whatever gets me and my family on the water I'm happy

 

[David Young]

If the compression checks out good, I would buy a 'complete' carb rebuild kit. New floats and everything. I would also order a 'complete' rebuild kit for the water pump (impeller) kit. Comes with a new metal plate that the impeller spins on. My old one was the factory original one and had grooves worn on it. Try to stick with factory original replacement parts, they seem to be higher quality and fit better

 

[Landonsideways]

Thank you dave. Will do this weekend. Planned on rebuilding the carb, done a lot of research and know I want to take my time and clean everything real good and label and note take. If I had the money I would just buy a new motor and take it to the mechanic every time it acted up but I don't. I want to give my son the same experiences I had growing up on the water. On the flip side, the best way to get to know your motor is to do stuff like this to it from the get go. Might be a blessing in disguise. Will get back to you all after doing all this. Thanks again. No idea how greatful I am having someone to talk through issues I might have with someone more knowledgeable than me....

 

[Landonsideways]

You guys use this site to get most of your parts?

 

[racerone]

Not interested in supporting your local boat repair shop ?

 

[Landonsideways]

I live in Meade ks, pop 1000. No boat shop. Closest is 2.5 hrs away

 

[F_R]

Yep, there's lots of miles out there in Kansas. I used to make regular trips between Wichita and Garden City and Colby. Garden City has a great zoo.

iboats has normal service parts such as carb kits, etc., and hosts this free forum. For other stuff go to the BRP website, http://shop.evinrude.com/

 

[David Young]

I know this isn't the same motor as yours or mine but this is the video I went by on 'how to remove the carb linkage'. I had a hard time trying to figure it out until I saw this video https://youtu.be/VDn9fAn7sjo

 

[Landonsideways]

Will check it out. And yeah, it's ok sometimes not living in the crowded parts but anytime you need anything more than a piece of bread you got to drive 2 hours to get it or wait a week until ups can get there lol.

 

[Landonsideways]

Ok guys, I'm feeling a bit relieved. Got the compression knocked out and reads 125, 125, and 130. From what I read that is very good. I wanted to wait till I confirmed compression before I started ordering carburetor kits and impeller. So time to order parts and check spark gap. Will probably be a week or so before I can get all that tackled but will get back with you all. Thanks

 

[randyray41]

Great find on the 77 75hp motor. I have a 78 70 hp that runs great. Knock on wood!!! Would love to find a 75 hp running for $250

 

[Landonsideways]

Finally got figured out how to reduce picture file size so I can post some pics. Am supposed to be getting carb kit and the entire water pump kit within next few days. Here are a few pics so you know what I'm feeling with. Got a pic of that wire I was asking if it should be of concern too.

 

[Landonsideways]

I am going to have to do a few things on the restoring side of things but will be threading a different place for that I guess is how it should be. It's a 77 15ft glastron bass boat so it probably needs a little attention

 

[racerone]

That wire is part of the " kill / stop " circuit.-------Looks like the motor has been apart for rebuild already.

 

[Landonsideways]

Well it does look like some attention has been payed to it. Head seal isn't factory. Should I be concerned if the compression reads 125 on 2 and 130 on the other?