flooding engine

[Yooper Knight]

Hello All

I have a Walbro carb on a B&S engine which no matter what I have done to it it still floods on start up. So bad that she won't even fire up and pours gas out of the muffler and up into the air filter. Checked the float, no problem, adjusted the screws from all the way in all the way out. Same problem. What's next ? As usual I am at a loss.

 

[Russ2251]

Has to be float related.
Needle could be sticking or damaged along with leaking seat.
May be maladjusted float level.
Pull float and place in a cup of gas for a few minutes to be sure it actually does float.
High and low speed adjustments would not cause this.

 

[Yooper Knight]

Well I took the carb apart, the float " floats " the needle valve looks good, 1 1/4 turns out on the screw, choke is free and clear, no crap in the bottom of the bowl also no leaks, I am trying to figure out how to adjust the float level. Thanks for the direction Russ but if I could pick yours or anyone else's brain a little bit more I would appreciate your help.

Red

 

[Kenny_McCormic]

How are you feeding it fuel?

 

[Russ2251]

There is (or should be) a tab on float that touches needle.
Bending this tab up or down determines float level.
Bent too far down and engine will flood.
There is a spec for this dimension and is not one size fits all.
What is make/model of carb?
Your carb may or may not look like that pictured.
See attached:

 

[Yooper Knight]

Hi Kenny : Gravity

Russ : Walbro Carb and the float is plastic

and Thanks Guys

Red

 

[Yooper Knight]

OK NOW it starts and runs for about 4 to 5 minutes then quits and FLOODS again to the point of dumping fuel out of the muffler ( a HOT one I might add can someone say " fireball " ? ) Until it does warm up in the few minutes it has, it is not smooth running, until right before it quits. Any ideas ?

Thanks again Guys


Red

 

[Kenny_McCormic]

Looks good and is good are different, put it under a microscope and you might get a different story. Check the seat.

 

[Russ2251]

Dump the plastic. It was crap, it is crap, it will always be crap.
I don't bother with anything other than fully adjustable metal carbs.
Is likely one of 4 things.
Cracked body (internal or external)
bad needle
bad seat
bad float (leak or maladjusted)
It's common for plastic Walbro's to crack.
Check body, float and jet areas carefully (as Mr. McCormic suggested).
Best bet would be to replace carb.
Did this flooding condition just suddenly appear?
Or did problem appear after dis-assembly/re-assembly?

 

[Kenny_McCormic]

Wait! they make plastic carbs!?!

 

[Russ2251]

Wait! they make plastic carbs!?!

Yup...I got a box full of 'em.
I have several Briggs and Lawn-boy types going back to 1980 on up to present.
Some folks remove jets to clean them and upon re-installing will over tighten them and crack the bodies. Doesn't take much to ruin them.

 

[Kenny_McCormic]

What a bunch of BS!

 

[jr dragster T]

That looks like the carb that was on the lawnboy 2 cycle I found in the garbage. Untill the mower pissed me off and I chucked it back into the garbage.

 

[Russ2251]

What a bunch of BS!

As in Briggs & Stratton?
Do a web search on plastic intake manifolds. You'll be amazed at what's out there. An example:
http://www.autoclinix.com/Manifold.htm
Ford is not alone in this.

 

[crazycart]

Reminds me of our truck...99 gmc burban has a plastic intake gasket...gotta put in a new one this weekend. They fail and make it burn oil and coolant.

 

[Kenny_McCormic]

Properly designed(metal where needed) a manifold could easily be plastic, but plastic cams just piss me off. The B&S 17hp OHV we have has a plasic intake mani and it is plenty strong.

But plastic cams are friggin ridiculous, whats next? Zinc flywheels? Plastic blocks?

 

[Russ2251]

I have used zinc flywheels because of the needed inertia but have since gone back to aluminum.
Plastic engine blocks have already been prototyped.
I also agree that plastic cams are friggin ridiculous but as yet I have not witnessed any problems with them. They've been in use for at least the last decade.

 

[Yooper Knight]

Thanks for your insight Gentlemen.

Russ this problem just started this season IDK where it came from it just started acting up one day and has grown progressively worse with time.

Oh well looks like a rebuild kit is in order here HOPEFULLY I can find one with a metal cast float.

 

[jr dragster T]

Thanks for your insight Gentlemen.

Russ this problem just started this season IDK where it came from it just started acting up one day and has grown progressively worse with time.

Oh well looks like a rebuild kit is in order here HOPEFULLY I can find one with a metal cast float.

Lol is desihned to float man Not be a rock and sink! You wont realy find cast float!

 

[Kenny_McCormic]

Metal floats are stamped and soldered sheet brass.