1979 Evinrude 75 hp WON'T GO!

drewkuch

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Apr 30, 2012
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Have a 1979 evinrude 75 hp outboard that starts and idles on land, but doesn't accelerate on water. I have to adjust with the choke and carb linkages to get it to go faster than 5 miles per hour on water. Otherwise, when you throttle forward, it just bogs down.

I've taken the carbs off and cleaned them, everything seems put back together correctly. I made new gaskets for my air intake box, but I highly doubt they are causing this problem.

Carbs need rebuilt?

Carb #323714

Engine #75943R
 

fireman57

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Re: 1979 Evinrude 75 hp WON'T GO!

Sounds like you missed some stuff in your carbs. You really need to run a small wire like from a bread wrapper twist tie through all the jets and orafices. You high speed jet is located behind the drain plug on the front of your carb. You also might need to do a link n sync to make sure that you have everything opening and closing at the right time. Do a search for it on here, it's a simple procedure. Also, make sure that your timing advance arm under the flywheel is traveling the full distance to the stop. It may be sticking.
 

boobie

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Re: 1979 Evinrude 75 hp WON'T GO!

Pull one spark plug wire at time when running and see if it's hitting on all the cyls.
 

drewkuch

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Re: 1979 Evinrude 75 hp WON'T GO!

Sounds like you missed some stuff in your carbs. You really need to run a small wire like from a bread wrapper twist tie through all the jets and orafices. You high speed jet is located behind the drain plug on the front of your carb. You also might need to do a link n sync to make sure that you have everything opening and closing at the right time. Do a search for it on here, it's a simple procedure. Also, make sure that your timing advance arm under the flywheel is traveling the full distance to the stop. It may be sticking.

Great, thank you for the information. Going to take the carbs back apart and make sure to clean them jets and orafices thoroughly. I searched for "link n sync" but couldn't find the post. Would you happen to have the url for it? Thanks for your time!
 

drewkuch

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Re: 1979 Evinrude 75 hp WON'T GO!

Pull one spark plug wire at time when running and see if it's hitting on all the cyls.

Great idea, why didn't I think of that? ha! Thanks for the advice. Going to work on it now, I'll see what I come up with.
 

fireman57

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Re: 1979 Evinrude 75 hp WON'T GO!

boobie if he has to mess with choke and stuff I have to believe it's fuel related. Drew there are a ton of posts on link n sync but I'm still betting on you not getting crud out of the carbs. Go to the search feature at the top of the page and type in link n sync.
 

boobie

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Re: 1979 Evinrude 75 hp WON'T GO!

Fireman, I guess it's just an old habit along with checking compression when I have a problem mtr. By pulling the plug wires you can pin point a bad cyl if it is a fuel prob.
 

fireman57

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Re: 1979 Evinrude 75 hp WON'T GO!

I understand. It seems like all I tell people to do is clean carbs anymore. I guess it's that time of year again.
 

drewkuch

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Re: 1979 Evinrude 75 hp WON'T GO!

My top carb's float needle is missing the rubber tip, so it's not sealing. I'll find a new needle and install it. Hopefully this fixes the problem!

Does anyone know how to adjust the throttle and gear cables? The round adjusting knobs the shape of a quarter, I'm just not sure what OEM specs are on how to adjust.
 

fireman57

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Re: 1979 Evinrude 75 hp WON'T GO!

Take the holder off and rotate the black knob to where your idle is where you want it. Then you will see above it a long bolt with a rubber tip.Screw that in to where it stops. do the same for your gear cable to where it goes into reverse and forward with the same amount of travel both ways. Put your cables back in your holder.
 

drewkuch

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Apr 30, 2012
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Re: 1979 Evinrude 75 hp WON'T GO!

Does anyone know where to find the "link and sync" post on here?
 

fireman57

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Re: 1979 Evinrude 75 hp WON'T GO!

just go to the search feature at the top and type it in. There are numerous threads on it. As long as your butterflies are opening evenly and your timing advance arm under the flywheel are going at the same time you should be fine. At idle does your roller cam line up with the start lines?
 
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