Mower stumbling, stalling

[Diggin It]

Craftsman 42" rider, bought in '10, Briggs 24Hp, Vtwin.

First off, it has a starter solenoid problem, clicks multiple times before catching to run the starter. So, I guess I need to find one of those.

Once running, it'll be OK for a while (time varies), but will begin to lose power, stumble and eventually stall. Playing with the choke will keep it running for a bit longer, but eventually it will die. Acts like a fuel problem. Have cleaned tank, blown out hose from tank to filter, replaced gas cap and filter ... no change. Have also tried various fuel treatments and system cleaners.

Thoughts are fuel pump (probably original), maybe fuel lines swelled internally. Also wondering if valve lash might be involved ... has not been checked in far too long. Fuel pump was grotey with buildup. Hit it with Gunk and blew the crud off in case there is a vent hole that needs to breathe.

Gas *** should *** be good as it's only a few months old. BUT, I'm also having similar trouble with a JD X-300. Runs for a while, then stumbles and dies. Same thing with choke to keep it running. Possibility of water in gas, but gas dryer doesn't seem to have made a difference.


I'm really not all that mechanical and don't want to dig too deep.


First step I guess might be to get new gas, maybe Rec Gas.

 

[dodge man]

Gas a few months old? As in two months or 8 months? Ethanol in it? I like to keep my fuel no more than 6 months old and be ethanol free.

Does that model have a fuel pump? Some don’t and are gravity. It might be time to clean the carb and/or rebuild it. That sounds intimidating but its not as hard as it sounds.

 

[Diggin It]

Feeling around in the shed for feeler gauges and I spot a small square box with Stens on it. Brand new starter solenoid I forgot I bought however many years ago.

Click click problem is solved.

Gas is probably 4-6 months old, bought sometime this Summer. Regular corn squeezin's. I'll be passing by a place that sells Rec Gas in a week or so and I'll get 5 gallons of that.

Still gotta find the feeler gauges to be able to check the valves.

Weird carb mounted up front under some of the exhaust for some reason. Stupid place.

Standard vacuum fuel pump, three hoses.

 

[oldnslo]

Compression test will tell you if valves are out of adjustment.

pull the fuel line that goes to the carb and place that in a container then crank engine over to see if you get good fuel flow. Diaphragm pumps can and do fail.

Also can be vacuum leak in line from engine to fuel pump or vacuum leak in fuel lines.

Does that carb have a drain screw in the float bowl? If yes crack it when engine stops to see if any fuel in the carb.

 

[Fuddyduddy1952]

What I have is a universal gas pump ($10 ebay) and clip leads (Harbor Freight). Cut plug off pump, add wire as needed (Dollar store extension cord is fine) with clip leads other end. Then you need a length of fuel line and clean container (1 gallon gas can, milk jug, etc).
Disconnect fuel line at carburetor and plug it.
Now feed carburetor with this, having new fresh gas. Clip pump leads to battery, red is +, black --.
If it runs fine, you have fuel delivery problem.
You can use pump later to fill tank, etc.
If it still has problems a new carburetor may not be expensive. If it's $30-$40 to me not worth rebuilding by the time you buy a kit.

 

[Racer4]

If you put gas dryer in the tank, that’s going to cause issues. BTDT. Drain your carb bowl into a glass cup, I bet you’ll find water in there.

 

[Diggin It]

I don't see a way to drain this carb.

One thing that bugs me though, is even after sitting overnight, I don't see fuel in the filter (clear body).

Thinking about replacing the hose from the tank to the filter.

 

[stevem5215]

My 24hp Craftsman Briggs engine was doing that also. I loan it out to my friend yearly. He said it started running rough in the summer sometime. I brought it home and dumped some "Mechanic in a bottle" that they sell at various places like Lowe's and after about 5 minutes it was back to normal. It cleaned whatever was in the carb and ran fine afterwards for a year (even over the last winter). Other fuel cleaners don't seem to have as good of a cleaning power as this stuff does. Give it a try.

 

[Diggin It]

Ehhh, I'll try anything.

I use MMO, SeaFoam and this stuff:

Rolled it out this morning to chop up some leaves. Ran for 15-20 minutes then started acting up again. Limped it back to the shed and managed to find just enough fuel line hanging in there. Replaced the line from the tank to the filter and from the filter to the fuel pump.

Rolled it back out and ran it for quite a bit longer without issue. Run time isn't consistent though so maybe, maybe not.

Still going to get some Rec Gas to use over the winter for the few odd jobs that always come up.

 

[Racer4]

I don't see a way to drain this carb.

One thing that bugs me though, is even after sitting overnight, I don't see fuel in the filter (clear body).

Thinking about replacing the hose from the tank to the filter.

There usually no way to drain the bowl other than removing the center bolt or shutoff solenoid. Do that and give the bowl a good cleaning. There’s probably water drops in there. When they get sucked into the passages within the carb, it will cause stalling or stumbling.

It’s perfectly normal to have the fuel filter only partially full of fuel. That’s just the way they work. If it’s completely empty, that would indicate a problem with the pump or line or something clogging the fuel outlet of the tank.