Lawnmower Fires then Dies

All,

Patient is a 2 month old Craftsman with a 4.5 HP Briggs and Straton motor. Gas is fresh, oil is up to full mark. Mower has been working OK. Last used about 1.5 weeks ago.

The mower will fire briefly if the primer dome is pushed. Then it dies after using the gas supplied by the primer push.

I have tried taking the air filter off and have tried loosening the gas cap (one thing at a time) with no change in results.

Seems as though it is not pulling gas after the initial firing. This is a new mower with only one run speed. The carb seems bone simple.

Any ideas where to start?

Douglas

Reply to
Douglas Fifield
Loading thread data ...

Do you have a suggestion on how to check for a pin hole? Thanks.

D.

Reply to
Douglas Fifield

could be you have water in the bowl or dirt in the bowl nut orfice

Reply to
ds549

I called Sears and the "kid" I talked to said that if I brought it in, they would send it out for repairs. Probably take 1.5 to 2 weeks. Before I did that, I wanted to check with the wisdom of the list and see if there was something simple I could check and perhaps avoid the hassle.

D.

Reply to
Douglas Fifield

Check and make sure you have not gotten a small pin hole in the primer bulb. If this happens, it will do exactly what you are describing.

Reply to
Old_boat

Sure, start at Sears. At two months it is under warranty ad you don't want to tinker with it and void the warranty. Let them figure it out.

Reply to
Edwin Pawlowski

No not really I found it on my sears mower by accident, Thing drove me nuts. Seemed that the primer bulb has a tiny hole in it around the edge where it was connected to the housing. I smeared some some blue permatex and it fised the problem.

LJ

Reply to
Old_boat

Take it in there, and tell them you want a "loaner" to mow your grass with while yours is out for repairs.

By the way, this isn't a "list", it's a newsgroup.

Reply to
Dan C

Float is stuck??? Maybe....

I'd remove the bowl and gumout everything.

Check to make sure that dirty gas isnt clogging up the fuel tank would be good too. Gravity needs to have it flow nice and easy.

Reply to
BocesLib

The fuel tank is underneath the carburator. Gravity is not a friend in this case.

D.

Reply to
Douglas Fifield

Fuel tank is underneath??? What the???

Crappy design then. If thats the case then there has to be some sort of pump to get the gas into the bowl. Sometimes they use a small diaphram pump that works off of crankcase pressure. These do go bad too.

What are you worried about right now if its under warranty then have it taken care of by them ASAP. Then just get back to us and say what the problem is/was

Tom

Reply to
BocesLib

UPDATE:

Tried the mower today and it started and ran fine. Only difference between today and two days ago is:

1) passage of time, and

2) temperature and humidity.

Two days ago it was beastly hot and humid. Today, the temps are in the low 70's (F) and the humidity is much lower. Everything else is the same.

Douglas

Reply to
Douglas Fifield

How does it keep the constant flow coming into the carb with the pulse vacuum of the engine in one of these types of carbs????

Reply to
BocesLib

Yeah, this happened to me. In my case, the ventri was clogged from the varnishes in the gas. Of course when you choke it and start up, you are basically manually making the rich mix in the carb. So it starts fine and dies in 2 seconds. If you don't use gasoline stabilizer, DO. It prevents gum-up in the venturi. I swear by this now after several weeks of intermitent behavior and crazy starts. I would add this to your gas can, and to the remaining gas in your tank. Consider cleaning your carb if this is recurring. The other thing about humidity could be a leaky electrical connection.. Is the plug new?

Reply to
les

He said the mower was 2 months old, and the gas was fresh. Do you really think the "ventri" is clogged? Do you think you need stabilizer over the summer when it's used every week?

You're quite the mechanic, huh?

Reply to
Dan C

Dan... Sure, I stick to my guns. I had new gas and the venturi was plugged from week to week.Small embuli of crude was contaminating the orifice akin to a cardiac vessel, and resurfaced once the pressure pulled it back into position. I'm offering possible scenarios. I'm not a mechanic, though a doctor sees things from his perspective and is willing to share experiences. Hope you feel better.......

Les

>
Reply to
les

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.