Need help on awakening a 1980 75 hp Evinrude

[rivertripp]

Hey guys,

I just bought a 1979 16 foot Cajun Special with a 1980 75 hp Evinrude on the back. I have replaced all three spark plugs, put a new fuel line, fuel connectors, and gas tank on, and I have put in a new battery and sprayed carb. cleaner into the three carberators. When I got to fire the engine up it just turns over but never fires all the way up. I am also going to change out the lower unit grease here in the next couple of days. This i my first boat I have officially owned, and need help on what I can do to figure out what is causing the engine to not fire up all the way. Any Suggestions?

Thanks,
Tripp

 

[kenmyfam]

Re: Need help on awakening a 1980 75 hp Evinrude

This link should help you out with what you need to know.
Welcome to iboats

http://forums.iboats.com/showthread.php?t=158086

 

[1946Zephyr]

Re: Need help on awakening a 1980 75 hp Evinrude

Agreed. A very good read and a lot of good tips.

 

[rivertripp]

Re: Need help on awakening a 1980 75 hp Evinrude

Thanks for the tip, I will def. check it out!

 

[rivertripp]

Re: Need help on awakening a 1980 75 hp Evinrude

New Problem... So along with what I did in my first post I have also replaced all the dry rotted fuel pump lines and changed out the lower unit grease. I am able to get the engine to turn over and fire when i spray some engine starting fluid into the carbs. but it will only run for around four seconds then turn off. It sounds like the carbs are not able to get fuel through them. I checked the fuel pump and each new line and fuel is getting TO the carbs. but that is all I have been able to determine so far. Anyone have suggestions on why the motor is not able to keep running after it is fired up? I am thinking I might have to rebuild the three carbs. in the motor so fuel will deliver through them.

-Tripp

 

[ScottinAZ]

Re: Need help on awakening a 1980 75 hp Evinrude

if the motor was parked without draining the carbs, they are most likely full of varnish. this will definitely make the engine run like crap until they are properly cleaned

 

[ezeke]

Re: Need help on awakening a 1980 75 hp Evinrude

Are you following the cold start instructions in your owner's manual?
Are you using a warmup lever?
Are you using the chokes as instructed in the owner's manual?
Are the carburetors synchronized?

http://forums.iboats.com/showthread.php?t=225510

 

[rivertripp]

Re: Need help on awakening a 1980 75 hp Evinrude

I will look through my owner's manual on cold start's and what to do, thanks for that advice. I am also curious to know about possible fuel pump malfunctions when the engine is running. Since I don't see any wires coming from the fuel pump I am assuming it is like a vacuum pump pulling fuel in the pushing fuel out. Are there turning wheels in the pump that could get lodged and jammed?

 

[ezeke]

Re: Need help on awakening a 1980 75 hp Evinrude

The fuel pump is strictly mechanical, working off the pulse created by one the pistons. That moves a diaphragm in the back of the pump, which opens and closes small valves.

The pump's only function is to lift the fuel from the tank to the carburetors' float bowls. After that, the pistons create a vacuum which pulls the fuel through the carburetors.

More on the fuel pumps here, with pictures: http://forums.iboats.com/showthread.php?t=240864&highlight=fuel+pump+sticky

 

[rivertripp]

Re: Need help on awakening a 1980 75 hp Evinrude

Thanks for the fuel pump link that helped out a lot. Looks like I am going to have to concentrate on the carbs.

 

[rivertripp]

Re: Need help on awakening a 1980 75 hp Evinrude

Well I got back after the evinrude today. I pulled the carbs. off and due to the carb rebuild kits I ordered two weeks ago still not coming in I decided to just clean them. I got the all three carbs pulled apart and cleaned, (they were extremly gummed up inside the bowls). I then put everything back on and added a fuel stabilizer. When I went to crank it up I sprayed to starting fluid into the throats and she fired right up....for about 20 seconds the shut off. This was better then my initial try which would only fire up for about 4 seconds. I then made sure the fuel pump lines were tight, and all was good. What do you guys think is going on? I also pulled apart the fuel pump and it was clean. Also another problem that has now arised is the choke on the side of the carbs is no longer working when I push the key into the ignition. Did I assemble to choke wrong or something when remounting the carbs? Thanks for the help!

 

[Jet Wrench]

Re: Need help on awakening a 1980 75 hp Evinrude

The carbs need to be disassembled and soaked in a carb cleaning solutuion overnight. Make sure that you remove the jets so that the solution can get inside the passages of the jets. Also, remove any rubber/nylon parts prior to dipping the carbs in the solution. You can purchase a can of this at an auto parts store, it's the size of a paint can and usually has a basket in it so you can place all of your small parts in. This will remove all of the varnish. Use an air compressor to blow all of the passages out after they have soaked, just be gentle without too much pressure.

 

[rivertripp]

Re: Need help on awakening a 1980 75 hp Evinrude

Hey Wrench,

I have already done that as well as bought a can of carb cleaner to give the cleaning some extra detail. I soaked them for about an hour and they looked great afterward.

 

[Bret L]

Re: Need help on awakening a 1980 75 hp Evinrude

Still sounds carb related to me. Check the jets themselves for obstruction. Should be soaked overnight but Ive cleaned them in an hour too. The elec choke you would have to break down the issue with a test light. Double check your jets themselves though, if fuel cant pass through them, she wont run.

 

[rivertripp]

Re: Need help on awakening a 1980 75 hp Evinrude

Thanks for the info Bret. Well good news I got the engine running!! The carbs turned out to be fine after all, however the choke still is not operating. When I push the key in, the valve that make the click sound and moves in and out of the choke silenoid is working, but it looks like the spring wire going to the choke links has been bent up and pulled around. I noticed it was like that when I bought the boat but I must have made it worse when I pulled apart the carbs. So to get the engine running I had to move the choke linkages by hand so the throats have the right air amount. How do I get this spring wire fixed, or do I need to buy a new one. Also the other adjustment I need to make is the engines idle. After the engine has warmed up and I pull the throttle down so the engine is in low idle it slows down then shuts off. I looked in my manual but could not find where to adjust the idle at. What do I need to do about this adjustment, and where do I find it?