Logo
FULL SITE MENU

Evinrude 70hp 1989 idle and throttle problems

D

dazzer

New member
Looking for some help with my Evinrude 70hp. It’s a 1989 VRO model with the VRO removed.


Model BE70TLCEM


Its been sitting up for about 2 years now I just got it out last week. It takes a while for it to start up and then idles rough and splutters every now and again. When I give it throttle it just cuts out. If I turn the low idle screw I can increase the rpm but if I turn the cam arm on carbs to rev the engine it dies.


I’ve cleaned carbs and made sure nothing was blocked. Replaced fuel filter and spark plugs. Good compression in all 3 cylinders.


I also noticed it’s not passing water through the tell tale. I replaced the impeller (old impeller was perfect) and made sure there no blockages by using compressed air through the water pipe.


Sometimes if I rev up the engine the water will start to come out but other times nothing. Could this be because it’s not idling right?


Is there anything else I should check? I brought it to a mechanic and he said the carbs were gone but wasn’t 100%. No interest in working with the older outboards so trying to figure it out myself.
 
I would revisit the carb work. I would also run a trimmer string up the pee hole could be blocked. I would also get a factory manual and do a link and sync. Also idle is set in gear and running.
 
flyingscott said:
I would revisit the carb work. I would also run a trimmer string up the pee hole could be blocked. I would also get a factory manual and do a link and sync. Also idle is set in gear and running.
Click to expand...

Iv done a link and sync. I followed the video on YouTube of a guy who recorded the OMC link and sync instruction tape.

Is there anything I should be looking out for when I strip the carbs? Is it possible I have them installed the wrong way i.e top carb is on the bottom and bottom is on the top? I know the middle carb can only be in middle because the arm that attaches to it is different from the other 2.

I stuck the air gun into the air tube in the lower unit and I could feel it coming out the pee hole on the upper unit but I’ll give the string a try.
 
Last edited:
Look at the main jet which is behind the brass screw in the bowl. Top and bottom are interchangeable. Where does the pee hole line come out on that? Is it the top of the block or the side? are you sure you have the water tube lined up correctly to the water pump housing? What is good compression?
 
flyingscott said:
Look at the main jet which is behind the brass screw in the bowl. Top and bottom are interchangeable. Where does the pee hole line come out on that? Is it the top of the block or the side? are you sure you have the water tube lined up correctly to the water pump housing? What is good compression?
Click to expand...


Ok iv had another go at it again today. I stripped the lower unit off and checked the water pump and pipes. I used compress air from the end of the pipe that sits over the water pump and could feel a strong flow of air out the pee hole. I then used a spray gun and shot water up the water pipe and water made it out the pee hole so im 100% sure now it’s not blocked. I tired with strimming wire but it wasn’t able to make it past the first bend.

There is still currently no water pumping out but it seems to tick over steadier now. I had to increase the low idle adjustment screw so it’s idling around 1,100rpm in a bucket of water. Once I get a chance to bring it down to dock I will reset the idle screw. Still sounds rough.

Is there anything else I can try with the water not pumping? The impeller is in good condition. There was about half an inch of play when I tuned the impeller on shaft not sure if that could be the cause?

And these are the results of compression test:
Cyl 1 105psi
Cyl 2 105psi
Cyl 3 100psi
 
flyingscott said:
Where does the pee hole line come out on that? Is it the top of the block or the side? are you sure you have the water tube lined up correctly to the water pump housing? What is good compression?
Click to expand...

The pee hole is on the side. And yeah I doubled checked today that the water pipe was aligned to the water pump housing when I was putting it back together.
 
Have you tried a drop test on it? While running, pull each spark plug wire one at a time to see if there is any change in engine performance.
Could impeller blades be curved the wrong direction? Would that make a difference? I'm not sure, but some of these experienced guys will know.
 
riopga said:
Have you tried a drop test on it? While running, pull each spark plug wire one at a time to see if there is any change in engine performance.
Could impeller blades be curved the wrong direction? Would that make a difference? I'm not sure, but some of these experienced guys will know.
Click to expand...

I haven’t but I will definitely give that a go. I’m a bit nervous running the engine again until i get some water pumping.

Yeah the blades are in the correct position. It was pumping water and then just stopped when I started having the idling issues. Iv ordered a new water pump kit so I will swap out all the parts and see what happens. It’s a pretty simple system so hopefully the new pump will sort it
 
There was a service bulletin that came out in 1994 to move the tell tale fitting to the top of the block !!----Your has not been done for some reason.----The latest factory water pump kit has information for you to upgrade the cooling system !
 
racerone said:
There was a service bulletin that came out in 1994 to move the tell tale fitting to the top of the block !!----Your has not been done for some reason.----The latest factory water pump kit has information for you to upgrade the cooling system !
Click to expand...


The tell tale on mine is on outside of the casing. If you look at the back of the engine, there’s a small plastic hole on the front right side. Is that the new position or should it be somewhere else?
 
dazzer said:
Looking for some help with my Evinrude 70hp. It’s a 1989 VRO model with the VRO removed.


Model BE70TLCEM


Its been sitting up for about 2 years now I just got it out last week. It takes a while for it to start up and then idles rough and splutters every now and again. When I give it throttle it just cuts out. If I turn the low idle screw I can increase the rpm but if I turn the cam arm on carbs to rev the engine it dies.


I’ve cleaned carbs and made sure nothing was blocked. Replaced fuel filter and spark plugs. Good compression in all 3 cylinders.


I also noticed it’s not passing water through the tell tale. I replaced the impeller (old impeller was perfect) and made sure there no blockages by using compressed air through the water pipe.


Sometimes if I rev up the engine the water will start to come out but other times nothing. Could this be because it’s not idling right?


Is there anything else I should check? I brought it to a mechanic and he said the carbs were gone but wasn’t 100%. No interest in working with the older outboards so trying to figure it out myself.
Click to expand...

Just a thought make sure your float is not upside down when rebuild.Yes it could have been dirty to begin with but failed again because the float was upside down
 
Does the tell tale hose fitting where hose attaches come out of the exhaust manifold on the port side ( boat speak ) of the block, yes or no ?---The factory service bulletin has instructions to plug that hole and drill a new hole on top of the block for the hose to come off.----The pisser outlet location stays the same at the back of the lower cowling.
 
Back
Top