Logo
FULL SITE MENU

Size air orifice?

J

JamesRo

Member
1988 40 horse evinrude, E40elccs spitting gas from the air orifice above the throttle. . I was reading another thread was talking about the air orifice should be a number 30. Mine reads 40. Is this the problem?
 
Thanks Tim. We know it's getting too much gas but I've lowered the floats to lower the levels.the stem goes from top to bottom of the carburetor so even a little bit of gas at the bottom of the bowl is going to get in it. I can blow through the hose with the carburetor upside down. I can't get air to go through. I don't know what else to do.
 
Just from my information, a 40 is within recommendations......did the symptoms start AFTER the carb overhaul?
 
No sir. It's been doing this since I bought it. I just didn't tear it down until I enjoyed it a few times. It actually runs pretty good like this. But I don't like seeing gas get in the water even if it's a little bit.
 
Thanks. You know, Tim. I don't think I've paid any attention. But I'll look tomorrow. What are you getting at?
I was just thinking. Maybe it's not how soon the floats closes the needle valve. But rather how little the floats opens to allow gas in. This is something I haven't adjusted. Probably won't matter�� And I guess the last carb guy didn't either. As I said it's been doing this all a long. Thing about it is. The seller brought the boat to his boat mechanic's business to show me it has good compression and assure me there wasn't too much wrong for $1,800 dollars. Which I think is a great deal for a welded aluminum boat, running 40 horse Evinrude and galvanized trailer. �� So why didn't his mechanic know this if it turns out it's this simple? ��
 
So why didn't his mechanic know this if it turns out it's this simple?
Click to expand...

Because engines can have cylinder damage and still have good compression. A compression test only proves cylinder will support combustin and is not a good indicator of engine condition. That why its more important to do a leak down. Also float level has nothing to do with fuel blown out idle jet, usually a reed problem or scuffed piston on exhaust.
 
Ok thank you. So it could be a reed problem. Would a scuffed piston on exhaust allow it to still function properly except for blowing gas from the idle jet. Btw, my grandkids call me pappy too. Makes me smile.
 
I have seen cowling insulation break down and get sucked into the carbs like a vacuum cleaner. You guessed it.......stuck in a reed valve or two.
 
What did you find with the reeds. In all my years of outboard repair, the only problem I've found in reeds is either rust related, debris related, or mechanic related. You must know, at your age and experience.......they sell tools to anyone. Pappy is one of our sharpest mechanics here.....now you guys make up. I've lost my temper with other techs here......but you know what? I still deeply appreciate what they do, to help guide complete strangers in the repair their motors........spending hours upon hours with little reward.
 
Last edited:
You said it idles good and runs good, Maybe looking for problems that are not there?Have you checked the primer? Which way is the red lever facing? Have you checked to see if it is leaking by? You set the floats with the carb upside down and the float level to the body?
 
Thanks, Scott. A lot of people are saying this is normal. As long as I don't run for a long time trimmed up it's not as bad. The primer works great, the arrow is pointing toward the top where the wires come out. I rebuilt the carburetors I held it upside down so the float would close the needle and tried to blow air through, no air went through. The only thing I didn't do was adjust the tab on the back of the float so it can't go down very far. Which I think this only would affect it if there's no gas in the bowl at all? ? Apparently gas is too readily available in the carburetor is reason it's spitting out of the air orifice.
 
I took the primer hoses off the carburetors and plugged the line on the carburetors. Accidentally pressed the key in because this is how I start it. I was surprised to see how much gas squirted out. A lot! But after it started, the problem persist. I hope I said it right because I remember moving the red needle making sure I had it manually off. I hope I turned it off again. I think off is pointing towards the wires coming out.
 
JamesRo said:
1988 40 horse evinrude, E40elccs spitting gas from the air orifice above the throttle. . I was reading another thread was talking about the air orifice should be a number 30. Mine reads 40. Is this the problem?
Click to expand...

The 1988 35hp & 40hp Idle Air Bleed requires a #40 (.040) air bleed jet.

Fuel being sprayed out the Idle Air Bleed jet would be due to the downward force of the piston(s) escaping somehow past the leaf valves of the intake manifold plate into the rear portion of the carburetor via the small holes just aft of the throttle butterfly.

Don't play with the float setting... there is but one setting, as follows:
********************
(Carburetor Float Setting)
(J. Reeves)

With the carburetor body held upside down, the float being viewed from the side, adjust the float so that the free end of the float (the end opposite the hinge pin) is ever so slightly higher (just ever so slightly off level) than the other end. And when viewed from the end, make sure it is not cocked.
********************
 
Last edited:
JamesRo said:
Thank you. Will do. I ordered leaf valves. Any advice here?
Click to expand...

Make sure the coverage overlap is as equal as possible on both edges of the leaf... and check the leaf for which side is better suited when seated over the openings as one side or the other may result in a slight air gap.

If a gap exists on both sides, crankcase pressure will no doubt slam it shut so that's really no big deal, but if one side makes it perfect, so much better.
 
Wow! Thank you, Joe. Awesome. I've worked on cars, motorcycles, small engines. I've pulled these two carburetors three times rebuilding them the third time. Runs the same. Runs great, just waste gas. And I'm a perfectionist. Ah haha. It's really not that bad unless I no wake with the motor trimmed up. I've never worked on a 2 stroke or reeds. You're third one who said reeds so I think it's right. I guess it's really the last thing to do unless I rebuild it. It's just that we wanted to enjoy the boat before I tore into the motor. I really appreciate you're tips too! I'm pretty sure to find something obviously obstructing or venting the reeds. And I know the problem might not even be visible. :)
Thanks again. ✌️
 
Back
Top