84-85 70hp Evinrude

[Bottom]

A couple weeks ago I was having a problem with my boat. It was bogging down and running like the throttle was half open, when it was all the way open.

Well 1 of the carbs had old gaskets in it, cleaned that and it ran better but not great. It would get on plane but the boat would bounce from the RPMs going up and down ( i assume). You could hear the motor though like it was higher and lower.

The boat would stop bouncing so much and the motor would sound more consistant if I tap the choke every couple seconds. I took the carbs off and didnt see anything in the bowls, checked for a leaks in the gas lines to the carbs and the tank.

I take it to a shop and he says the lower unit seems like it locking up sometimes, and that there was shavings in the oil.

My question is if it is the lower unit would the choke help it run better when I hit it??

Feel free to post any thought you may have as i'm lost.

 

[ezmobee]

Re: 84-85 70hp Evinrude

Nope. That certainly sounds like a fuel delivery issue to me. Instead of hitting the choke, try pumping the fuel primer bulb when it's acting up and see if that helps. If it is, you may have a bad fuel pump.

 

[Bottom]

Re: 84-85 70hp Evinrude

Nope. That certainly sounds like a fuel delivery issue to me. Instead of hitting the choke, try pumping the fuel primer bulb when it's acting up and see if that helps. If it is, you may have a bad fuel pump.

Will do, Im about to take it out and see.

 

[Bottom]

Re: 84-85 70hp Evinrude

Well I didnt take it out today, It was getting dark so I'll take it out tom.

I'd like to hear some more opinions on it though.

Thanks

 

[Bottom]

Re: 84-85 70hp Evinrude

Well I didnt take it out today, It was getting dark so I'll take it out tom.

I'd like to hear some more opinions on it though.

Thanks

So I put a new prop on, changed the lower unit fluid, took the carbs apart and hit them with carb cleaner really and good took it out yesterday. It ran good for alittle while, then started to bog down again (hit choke and it ran good as long as I hit the choke often).


Any help?

 

[Home Cookin']

Re: 84-85 70hp Evinrude

fuel pump, fuel lines, air in fuel lines, carbs need more work.
Inconsistent motor could be spark plugs, too.

 

[Fisherball]

Re: 84-85 70hp Evinrude

Did you install a rebuild kit in the carbs?

I've been running an '81 Johnson 70 hp for 6 years with shavings in the lower unit. Change my fluid twice a season. Someday it will fail & I will rebuild it. (Unless the economy changes & I have the cash b/4 it breaks!)

 

[willamettejeff]

Re: 84-85 70hp Evinrude

You have a fuel delivery problem. Try doing what Ezmobee said first. If problem goes away with pumping the primer bulb, then try running on a different tank and hose. If problem remains, then problem is with the fuel pump or carburetors. Also, be sure to change all your fuel hoses from the carburetors back to the fuel tank with ethanol resistant ones if you have not already done so.

-- Jeff

 

[scrampbell]

Re: 84-85 70hp Evinrude

In your carb cleaning did you physically clear out the orifice plugs? These routinely get gummed up as the alcohol in the fuel causes the fuel lines to sluff off and get stuck in there.

You can clear these out without removing the carbs... Just take off the screw plugs and GENTLY shove a paperclip in there. Just make sure the paperclip goes all the way in... and remember to be GENTLE.

 

[tedious]

Re: 84-85 70hp Evinrude

I agree, it's a fuel delivery problem - could be carbs, fuel pump, or a restriction in the tank, filter, or lines. In your position, I would start with a full carb rebuild - not that difficult to do.

Also, find another shop - why were they fooling with your lower unit (at your expense) while they were supposed to be looking at why the motor was not running well at speed?

Tim

 

[Bottom]

Re: 84-85 70hp Evinrude

I agree, it's a fuel delivery problem - could be carbs, fuel pump, or a restriction in the tank, filter, or lines. In your position, I would start with a full carb rebuild - not that difficult to do.

Also, find another shop - why were they fooling with your lower unit (at your expense) while they were supposed to be looking at why the motor was not running well at speed?

Tim

I took the boat to the shop, they told me they put the motor in the tank to run it and see what the problem was. I was told the lower unit was sticking and unsticking so they didnt go any further and that that was my problem. IDK i'm a motor noob!