Spitting gas.

[titaniumneck]

My friends 1985 70 hp evinrude is spitting gas from the top low pressure, idle jet. I was told that he has had the carburetor rebuilt a couple of times. From the amount of build up of old fuel down the front of lower section of motor and front of bracket completely covered with years of old fuel. It's has been spitting gas for years.
Now, question is, put rubber plug in each of the 3 carburetors low idle Jets and that stopped the gas from spitting out and idles the same. Forgot to mention adjustment screws were screwed in bottomed out, almost stripped heads of screws trying to get them out. Will plugging these Jets hurt anything?

 

[racerone]

What do these adjusting screws look like ?----Are you sure these carburetors have mixture adjusting screws ?----Gas spitting out of carburetors should be drawn into the engine via a drain hose at the bottom of the air box.

 

[boobie]

Got a model # ??

 

[wrench 3]

How about a picture?

 

[titaniumneck]

Screw is above carburetor throat, took out, believe it to be brass, quarter inch long, 8/32 size, 1/16 hole through middle. I believe the problem is that he has had them, carburetors rebuilt twice in the past, but looks like they did the bare bones kit with of rings, float, gaskets, and float needle valve.
I think that the rest of each of them need to go ahead and have all the brass changed out. Seats, low speed pickup jet, high speed jet and so on. It looks like all the brass is original 1985 and is just worn out. Because Jets are all clean and clear, just worn out over 33 years. What ya think.

 

[racerone]

Those wee brass jets are not adjustable.----They are screwed in tight.-----Spitting of fuel may be normal on that engine.---Your opinion may vary on that.----What other trouble shooting has been done on this engine ?

 

[flyingscott]

Spitting of fuel is very normal for that motor. That is not a 1/16" hole in there, the hole size will be on the jet itself. They are NOT adjustable and You CANNOT plug that orifice with a rubber plug it needs to draw air in through that hole. The fuel running over the motor is normal when the airbox gasket fails or the reclaim hose is not reconnected. Also make sure the gasket between the carbs and airbox are in good shape especially where they cover the idle orifice.

 

[oldboat1]

Isn't that a carb with both a fixed air bleed orifice and an adjustable low speed needle? Seems like kind of a strange duck, and it might be possible for the thing to work with the orifice plugged, using the needle adjustment to compensate.

It sounds like the carb is long overdue for a thorough cleaning -- thinking if the passages and vents are clear the problem might go away (or be improved, anyway -- although sounds like some leaking is a feature).

That point about jets wearing out came up recently in another thread, and don't know what to make of that. They are easily damaged by attempted removal or aggressive cleaning, but don't know about the wear issue. If it were mine, I would pull the carb apart and open it up for soaking and cleaning, leaving fixed jet(s) in place -- see if there was an improvement after that.

 

[flyingscott]

Only the early model 1985 70 hp will have the adjustable needle later ones got a different carb. Give us a pic of the carb to know which one we are dealing with. And get a book that tells you how a carb works before you cause some real damage to it.

 

[boobie]

Agree, a pic would be real nice.

 

[titaniumneck]

No Title

The brass one is the existing jet, the others are the ones I want to replace with, stainless steel allen head.

 

[interalian]

The brass one is the existing jet, the others are the ones I want to replace with, stainless steel allen head.

You don't replace jets with plugs. That defeats the design of the carb. If you've boogered up the jet, just get a new one to match.

 

[flyingscott]

The brass one is the existing jet, the others are the ones I want to replace with, stainless steel allen head.

Go back to post #7 and GET A MANUAL and learn how carbs work before you do something you can't fix.

 

[racerone]

Are we trying to re-invent the wheel ?

 

[boobie]

If I remember right it was normal for that motor to spit fuel out of that jet on the upper carb. I can't remember the cause but this info came from OMC at the time.

 

[emdsapmgr]

The throat of the upper carb will spit a little fuel. Normal. The carb has an internal crank oiling circuit that winds up spitting a little fuel out the throat of the top carb after the crank is oiled. The slight residue collects at the bottom of the airbox and is recirculated into the crankcase to be burned.

 

[titaniumneck]

Ok, everyone, my thick skull gets it now. I will put in the original jet screws and make sure the "recycling" pipe from the cover is not clogged. Did find that bottom gasket of breather cover is broken which explains why so much gas/oil mixture is caked all over the front of motor.

 

[daselbee]

Can you not tell that the brass jet has a hole through it, and the steel plugs you show DO NOT?

 

[wrench 3]

Can you not tell that the brass jet has a hole through it, and the steel plugs you show DO NOT?

That's because he wanted to get rid of the hole. But it sounds like he's educated now.

 

[titaniumneck]

With all due respect, chill out commander. The whole reason I thought about replacing them is because the gas was spitting out of the hole. And the stainless didn't have hole for gas to spit out of.
Now that I know that it is not uncommon, and that there is a recycle tube, that the biggest problem is that the gasket being torn at the bottom of carburetor cover was leaking gas faster than the pickup tube could recycle.
I may be slow, but not dumb.