Repairs Have to prime by blowing into tube -- runs super rich after that. Help!

[Grasschop]

I'm hoping to resurrect my Dad's early 80's Lawnboy push mowever. (Not sure of model, will update post when I can look for it. Looks like THIS though.)

It will not prime by pushing the button any less than an infinite amount of times.
I found if you pull the hose off the prime button and just blow in it until gas drips out of the air filter, it will then start no problem. I'm assuming its pulling the gas in through the air filter and starting at that point.

So now once it's started, it smokes a decent amount which I'm assuming is a result of running very rich. It works fine like this but I don't want to annoy my neighbors with the little blue cloud that will follow me around.


If I were to try repair myself (which I'm very interested in) any idea what parts are the culprits?

Should I get a quote to have it repaired or is it just past its time?

Thanks!

 

[Two-Stroke]

I sounds like the primer bulb isn't pumping and should be replaced. The primer bulb is actually an air pump -- it pumps air into the carb which then pumps a little gas into the engine. If you disconnect the tube (the one from the bulb to the carb) and press the bulb does it pump any air?

Also... is the tube in good shape?

 

[Grasschop]

Thanks for the reply.

The bulb is new as of 2 years ago, same with the hose. They're both in great shape but I will disconnect from carb and test that it does actually blow air and will repost.

 

[Grasschop]

OK So it's a Lawnboy 5124.

Runs VERY rich when cold. Decently rich when warm.

The bulb does work beautifully, however the carb must just require an insane amount of air to get going.

Any idea on what would need to be replaced to fix the rich problem?

 

[Two-Stroke]

The first thing I'd check is the float valve. If it isn't shutting off the flow of gas when the float chamber is full, the gas will continue to flow -- so way too much goes through the carb.

Assuming the air filter isn't clogged (that will make it run too rich) then too much gas is flowing. Your mission is to find out how.

 

[Grasschop]

Great, thanks for the help. You've given me direction where before I had none.

 

[Grasschop]

So I wimped out and had it repaired.

But for those interested, this is what it got and it runs great now:
Rebuild carb
remove old fuel from tank/carb
adjuts ignition and carb
clean air filter
champion spark plug (instead of ngk which I had)
shorten primer/fuel line
sharpen/balance blad
cleaned/adjusted reed valve
float valve kit

 

[WhyZed]

Well I supposed I best get myself into the shop for those upgrades cuz Im almost always looking for someone to blow into my tube to get me primed! :laughing: