Engine flooding out at low speed

[swamp creek]

1981 evinrude 35 hp. The motor had a small skip/jook to it as it was running WOT. It would work fine when some one pressed the bulb as this happened. So i cleaned the carbs and put it back on. It still did it. New bulb, lines, changed 3 tanks, still does it. Now not only that, it will flood out at a low idle speed (no wake) and will not crank up. I'm going to fix the electric choke on it tonight, and maybe adjust the low idler screw. It runs fine on the hose. Like always.

It left me in the florida flats on a 100 degree day for a few hours. Stick steering boat so its not fun crawling to the back. Finally I got it to crank by burning the plugs and sitting them out for a while, and turning it over with them out a couple times.

Any ideas on what might be flodding it out?

 

[flyingscott]

Did you put the float assembly and needle in correctly? Did you change the float height? Needs to be set level with the carb body when it is upside down. Low speed needle should be 1.5 turns out from lightly seated to get a start. Make the rest of the adjustments after it is running and warm. Also sounds like more of a fuel pump problem

 

[swamp creek]

I didn't mess with the float height, and needle went back in correctly. I'm taking it off again today and seeing if it is sitting level. I will probably change the fuel pump out too.. Won't hurt anything for sure.

 

[jakedaawg]

On those 35 you can put the float in upsiide down accidentally.

 

[swamp creek]

I redid everything again. Took it out and still the same damn problem.. This is beyond me, to a mechanic it goes. I have cussed it enough.

 

[gm280]

Is your float fuel soaked? Is sounds like that is the problem. JMHO

 

[scout-j-m]

The fact that pumping the primer bulb helped at high speed and that it only floods at low speed leads me to think that you have a bad fuel pump. The diaphragm may be ruptured just enough that it is whats causing fuel to leak through it directly into the crankcase and creating too rich of an idle speed mixture but then at high speed the ruptured diaphragm isn't able to draw up enough fuel to run well without pumping the bulb.

 

[boobie]

Edit.....

 

[swamp creek]

when i rebuilt the carb the skip at high speed went away, but the low idle problem continued. It could be the fuel pump. I wanna see what this guy finds out.

 

[valvebounce]

Don't know the engine,but I would be looking at the float fuel cut off pin/valve.
If it is sticking or worn it could be failing to cut off,and the top end could be effected if it is jamming before it reaches wide open.
In theory,whatever the amount of fuel supplied by the pump is,it should be controlled by the float and needle cut off.

 

[Vic.S]

What valvebounce says.!

If it is flooding then its because the float and needle valve are not controlling the fuel flow into the carb the fuel flow into the carb. Cannot really be much else.

Inspect the float, check its installed correctly and check the height.

Look at the needle valve for debris on the needle tip and on the valve seat,......... probably just as well to replace them . The whole assembly is under $10.
Be sure to fit the little spring clip that links the needle to the float arm or you'll have the opposite trouble.

 

[scout-j-m]

What valvebounce says.!

If it is flooding then its because the float and needle valve are not controlling the fuel flow into the carb the fuel flow into the carb. Cannot really be much else.

Inspect the float, check its installed correctly and check the height.

Look at the needle valve for debris on the needle tip and on the valve seat,......... probably just as well to replace them . The whole assembly is under $10.
Be sure to fit the little spring clip that links the needle to the float arm or you'll have the opposite trouble.

I think he said pumping the bulb at WOT helped which would mean it is starving for fuel. Maybe I misinterpreted it, but I think he was saying pumping the the bulb at WOT helped it smooth out. Op said it was flooding at low speed but I'm not sure how that was confirmed.

 

[valvebounce]

SOUNDS LIKE THE CUT OFF PIN CLIP IS NOT ON CORRECTLY___ IF THE FLOAT DOESNT DROP THE BOWL WILL EMPTY
IT MAY DROP WITH VIBRATION OR UNDER ITS OWN WEIGHT IF IT STICKS IN THE DOWN POSITION IT WILL FLOOD
MY APOLOGIES FOR USING CAPITALS<THE PC IS PLAYING UP>

 

[swamp creek]

$75 and its working like new. I've already invested more than that with my time trying to figure it out. He adjusted the float and needle, and adjusted the carb. I trolled around a lake the other day with no cut offs, it ran 22-23 mph WOT.