Export thread

Hi Gang, Hoping somebody might have run across this problem: My Craftsman tractor has a Briggs & Stratton "Platinum" 540 cc, 21 hp engine. It runs great with a full tank, but stalls out as the fuel level approaches 1/2. I thought it was a fuel line or filter issue, so replaced filters and replaced lines and didn't help. This problem is two seasons old now, just filling the tank is an ok work around, but thought I might try to fix it this summer.

I'm thinking it might be a dirty carb issue, but not sure why the 1/2 tank vs full tank would matter, unless a full tank supplies more pressure to push fuel through??? Not sure if that is even possible.

Before I spend the time take apart the mower to get to the carburetor, I was hoping someone could confirm that it is likely a carburetor problem. If it is, should I replace carb or just clean it? (10 years old tractor).

Adding my "solved" post here for convenience:

UPDATE: Hi All, thank you for all of the input. Yesterday I swapped out the paper filter for one of those red plastic filters (yes, the same one that Steve's video says is worthless) and now the engine runs great right down to empty. I also made a slight change in the fuel line path by bypassing the little plastic harness that hangs off the bottom of the fuel tank. That harness keeps the fuel line from flopping around but also makes the first few inches totally flat instead of a nice downhill feed down to the carb. I believe the original filter was the red plastic type and I changed it out for the "good" kind a few seasons ago because that is what Sear Parts Direct gave me as a compatible filter. I changed it out a 2nd time when this problem came up last year, so a dirty filter was not the issue. I suspect that the paper filter is just too fine unless you have a fuel pump to force the fuel through.

How about posting the units model and serial numbers. Briggs has lots of engines out there and I really really hate guessing which one you have. Look on the valve covers

This time of year, very well could be a carb issue. People are dragging out mowers for the season.

slomo

It also would to have the mower model number too.

We are not physic.

Does your engine have a fuel pump? Might be a partial clog on the carb needle.

I would drain and FLUSH the fuel tank. Install new hoses with a paper filter and a fuel shut-off valve. Clean and or rebuild the carb.

slomo

The Tractor Model # is 917.289223. The serial # on the engine cover is 090 928 ZD 64 948

Thnx!

slomo said:

Does your engine have a fuel pump? Might be a partial clog on the carb needle.

I would drain and FLUSH the fuel tank. Install new hoses with a paper filter and a fuel shut-off valve. Clean and or rebuild the carb.

slomo

Click to expand...

I've already cleaned the fuel tank, lines and changed filters so I guess I'll be pulling the carb tomorrow. Thnx!

Sorry guys, clearly I need help! The right model number from the valve cover is 331877 1371 B1 090925Z

Any additional advice is appreciated. Otherwise, I'll start taking it apart to get to the carb. Thnx!

FatJack said:

Hi Gang, Hoping somebody might have run across this problem: My Craftsman tractor has a Briggs & Stratton "Platinum" 540 cc, 21 hp engine. It runs great with a full tank, but stalls out as the fuel level approaches 1/2. I thought it was a fuel line or filter issue, so replaced filters and replaced lines and didn't help. This problem is two seasons old now, just filling the tank is an ok work around, but thought I might try to fix it this summer.

I'm thinking it might be a dirty carb issue, but not sure why the 1/2 tank vs full tank would matter, unless a full tank supplies more pressure to push fuel through??? Not sure if that is even possible.

Before I spend the time take apart the mower to get to the carburetor, I was hoping someone could confirm that it is likely a carburetor problem. If it is, should I replace carb or just clean it? (10 years old tractor).

Thnx!

Click to expand...

Try to run it again until it shuts off and then take off the fuel cap or unscrew it a little. Maybe it is the cap that is blocking from air from flowing inside.

semimechanicman said:

Try to run it again until it shuts off and then take off the fuel cap or unscrew it a little. Maybe it is the cap that is blocking from air from flowing inside.

Click to expand...

I think I tried that last summer, but I'll give it another shot. If it works it's a lot easier than taking the carb apart. Thnx!

FatJack said:

Hi Gang, Hoping somebody might have run across this problem: My Craftsman tractor has a Briggs & Stratton "Platinum" 540 cc, 21 hp engine. It runs great with a full tank, but stalls out as the fuel level approaches 1/2. I thought it was a fuel line or filter issue, so replaced filters and replaced lines and didn't help. This problem is two seasons old now, just filling the tank is an ok work around, but thought I might try to fix it this summer.

I'm thinking it might be a dirty carb issue, but not sure why the 1/2 tank vs full tank would matter, unless a full tank supplies more pressure to push fuel through??? Not sure if that is even possible.

Before I spend the time take apart the mower to get to the carburetor, I was hoping someone could confirm that it is likely a carburetor problem. If it is, should I replace carb or just clean it? (10 years old tractor).

Thnx!

Click to expand...

I had a similar problem with my deere d140. It would starve for fuel after running for a while. I changed everything and that did not help. Carried to a national dealer, they changed carburetor ($500), did not help, and wanted to change manifold ($600). I told them to put my old carb back on, and I will pick it up.
I got it home and looked at everything I could , and did not find anything.
Finally I removed the gas tank, and Inside I find a PVC Pipe fitting, A brass Slug about the size of a quarter, and a brass ring like a key ring only bigger.
With the sleeve that is in the filler port of the tank, I was unable to get these items out of the tank, so I removed the intake from tank that feeds the engine. This intake is just a straight pipe with an open end that sits about 1/8" above the bottom of the tank.
The slug in the tank about the size of a quarter was getting suck up to the bottom of the intake pipe by the vacuum from the engine causing it to starve for fuel.
Solution: I cut 4 small "V" shapes in the bottom of the inlet pipe and and reinstalled it in the tank and reinstalled the tank in the mower, the foreign objects are still in the tank, but the engine has not stalled for lack of fuel since.
Not sure this is your problem, but it fixed mine. good luck

FatJack said:

Hi Gang, Hoping somebody might have run across this problem: My Craftsman tractor has a Briggs & Stratton "Platinum" 540 cc, 21 hp engine. It runs great with a full tank, but stalls out as the fuel level approaches 1/2. I thought it was a fuel line or filter issue, so replaced filters and replaced lines and didn't help. This problem is two seasons old now, just filling the tank is an ok work around, but thought I might try to fix it this summer.

I'm thinking it might be a dirty carb issue, but not sure why the 1/2 tank vs full tank would matter, unless a full tank supplies more pressure to push fuel through??? Not sure if that is even possible.

Before I spend the time take apart the mower to get to the carburetor, I was hoping someone could confirm that it is likely a carburetor problem. If it is, should I replace carb or just clean it? (10 years old tractor).

Thnx!

Click to expand...

I had the same problem with a kohler in my craftsman, the manual showed a 51 micron fuel filter which was for an engine with a fuel pump.
mine did not have a pump, after a lot of research, I found that it should be a 75 micron filter.
the only thing I did was put on a kohler 25-05021-s filter and have had no problem since.
might be something to look into.

Some suggestions....

• I've had the same issue with clogged fuel strainers inside the bottom of the fuel tank
• On a tiller recently, there was a bend in the fuel hose coming directly off the fuel tank. It was a tight 90 deg bend. Due to prolonged storage with fuel in the system, the ethanol ate up the inside of the hose and the bend collapsed. Fuel could only get through the blockage when the tank was full because of the "pressure" a full tank created.
• Newer fuel tanks also have elaborate EPA-approved breather systems that only allow air to come in, but keep fumes from escaping the tank. These are usually EXTREMELY delicate flapper systems that newer fuels can make stick closed or make intermittent.

Not saying one of these is your exact issue, but rather the "full tank" requirement means it's far more likely related to the fuel cap, fuel tank, or the hoses and other bits that connect to the carb, rather than something inside the carb.

Next time it happens remove the fuel line from the fuel pump. If fuel is flowing from the tank to the pump, problem is between the pump and carb. No fuel problem is between the tank and pump.

You definitely get more pressure to the pump when the tank is full. Seems like the pump has an issue.

I had that problem with a John Deere for a couple years. I finally fixed it by taking the cap apart carefully and running a drill bit down through the center hole a tiny bit bigger than the original hole.
I had noticed the existing hole had a white scum ring around it from the alcohol in the gas. Reassembled the cap and it has run fine ever since.

Don't know which carb you have. Some had a screen behind the steel hose nipple. If it has a plastic nipple. I don't think it has a screen.

Sounds like your gas tank vent is clogged and your building up a vacuum in your tank. If there is a vent hole , you can clear it out with a small drill bit. Husqvarna tractor fuel tank caps are notorious for this.

Does the fuel line come out the top of the fuel tank? If so, it may have a leak about halfway down inside the tank.

Is it a gravity fuel system or does it have a fuel pump?

Hammermechanicman said:

Is it a gravity fuel system or does it have a fuel pump?

Click to expand...

Great question. OP disappeared. As they say on Duck Dynasty, "He gone".

slomo

Hi All, Thanks for all the input. I was away and computer free for the weekend so apologies for the delay. There is no fuel pump, gravity fed, so I am going to wait for it to happen again and then investigate in order: 1) air lock/vent in tank/cap 2) fuel filter (too fine?) 3) the whole fuel line end to tend 4) carb.

I will post what I find out.

Common issue on gravity systems is wrong fuel filter. Many paper type filters have small enough pores that the fuel surface tension causes fuel to stop flowing at a certain level in the tank. Also, a fuel line that ruses up higher than the bottom of the tank will cause fuel flow to stop at the height of the fuel line.

slomo said:

Great question. OP disappeared. As they say on Duck Dynasty, "He gone".

slomo

Click to expand...

"I'm back, Jack"!


Generally on gravity feds i usually fit the red or white briggs filters, however i've also used Wix 33011 on my own gravity fed systems with no issues.

Scrubcadet10 said:

"I'm back, Jack"!


Generally on gravity feds i usually fit the red or white briggs filters, however i've also used Wix 33011 on my own gravity fed systems with no issues.

Click to expand...

The stens paper filter seems to work ok with gravity systems but i fit the red screen filters on customer machines just to be sure. Every year i get a couple mowers in where cust wanted a better filter and installed a paper one and then have fuel flow problems.

Never had a problem with paper filters. All mowers will suck the tank dry.

slomo

slomo said:

Click to expand...

I think Steve was too busy emptying those cans behind him when he filmed this one.
Yes a paper filter will filter finer than the screen
However if the crud is fine enough to pass through the screen, it will also pass through the main jet & on most carbs the idle jet as well

Probably tens of millions push mowers came with no type of fuel filter. When equipment started having fuel pumps it was easy to add a filter. The original filters were there because metal tanks were prone to rusting. With the switch to plastic tanks rust isn't much of a problem but filters don't hurt anything so they stayed. I have changed hundreds of fuel filters and the only plugged up ones was from water or the jelly like phase separation goo you get from old E-gas. I have cleaned hundreds of carbs and i i can't remember the last one that actually had a problem from dirt. Usually old gas is the problem. Most fine dirt settles out in the bowl of float type carbs and not cause a problem.
Use or don't use your filer of choice. Whatever works for you.

bertsmobile1 said:

I think Steve was too busy emptying those cans behind him when he filmed this one.
Yes a paper filter will filter finer than the screen
However if the crud is fine enough to pass through the screen, it will also pass through the main jet & on most carbs the idle jet as well

Click to expand...

People watch this and then go out and put a filter on thay MAY or MAY NOT work. Depending on the height of tank above the carb and the micron size of the paper element things might not work properly.

FatJack said:

Hi Gang, Hoping somebody might have run across this problem: My Craftsman tractor has a Briggs & Stratton "Platinum" 540 cc, 21 hp engine. It runs great with a full tank, but stalls out as the fuel level approaches 1/2. I thought it was a fuel line or filter issue, so replaced filters and replaced lines and didn't help. This problem is two seasons old now, just filling the tank is an ok work around, but thought I might try to fix it this summer.

I'm thinking it might be a dirty carb issue, but not sure why the 1/2 tank vs full tank would matter, unless a full tank supplies more pressure to push fuel through??? Not sure if that is even possible.

Before I spend the time take apart the mower to get to the carburetor, I was hoping someone could confirm that it is likely a carburetor problem. If it is, should I replace carb or just clean it? (10 years old tractor).

Click to expand...

UPDATE: Hi All, thank you for all of the input. Yesterday I swapped out the paper filter for one of those red plastic filters (yes, the same one that Steve's video says is worthless) and now the engine runs great right down to empty. I also made a slight change in the fuel line path by bypassing the little plastic harness that hangs off the bottom of the fuel tank. That harness keeps the fuel line from flopping around but also makes the first few inches totally flat instead of a nice downhill feed down to the carb. I believe the original filter was the red plastic type and I changed it out for the "good" kind a few seasons ago because that is what Sear Parts Direct gave me as a compatible filter. I changed it out a 2nd time when this problem came up last year, so a dirty filter was not the issue. I suspect that the paper filter is just too fine unless you have a fuel pump to force the fuel through.

Hammermechanicman said:

The stens paper filter seems to work ok with gravity systems but i fit the red screen filters on customer machines just to be sure. Every year i get a couple mowers in where cust wanted a better filter and installed a paper one and then have fuel flow problems.

Click to expand...

Yep! That was me, though I didn't ask for a better filter, it's just what Sear's sent me as the "compatible" filter. Now that I know a micron from Nikon, I know better.

Don't pat yourself on the back too fast. You forgot to ask "Why?"

Why is the filter clogged ? I've owned a TroyBilt with a Honda engine for 17 years. The filter is not clogged on it.

What I'm saying is that the clogged filter is merely a Symptom of another problem. Unless you fix the real problem, then you need to be buying your filters by the case. And you can buy any color you want because they'll all be clogged again in short order.

FatJack said:

UPDATE: Hi All, thank you for all of the input. Yesterday I swapped out the paper filter for one of those red plastic filters (yes, the same one that Steve's video says is worthless) and now the engine runs great right down to empty. I also made a slight change in the fuel line path by bypassing the little plastic harness that hangs off the bottom of the fuel tank. That harness keeps the fuel line from flopping around but also makes the first few inches totally flat instead of a nice downhill feed down to the carb. I believe the original filter was the red plastic type and I changed it out for the "good" kind a few seasons ago because that is what Sear Parts Direct gave me as a compatible filter. I changed it out a 2nd time when this problem came up last year, so a dirty filter was not the issue. I suspect that the paper filter is just too fine unless you have a fuel pump to force the fuel through.

Click to expand...

I like Steve's videos but he needs to sober up and study up on fuel filters and fluids.??‍

Hammermechanicman said:

I like Steve's videos but he needs to sober up and study up on fuel filters and fluids.??‍

Click to expand...

"How well does a ice cold Beer flow through a red briggs filter, compared to a paper filter"

Scrubcadet10 said:

"How well does a ice cold Beer flow through a red briggs filter, compared to a paper filter"

Click to expand...

I need to do go get a couple more cases of beer. I'll get back to you tororrow.

Used the Briggs 691035 style filters on all of the smaller Kohler, Briggs, Tecumseh powered riders for years without fuel flow issues. Started having issues with fuel not flowing properly out of fuel tanks in 2012 which is the year that they discontinued the vented fuel caps and started using the vapor recovery type systems which operate under a slight tank vacuum. So for the non fuel pump riders I use the white pancake type Briggs filter. I will not use the red pancake style filter on any engine Long story for another time but had issues in early 2000's with sand infiltration through the red pancake filters causing the float valve not to seal.

It smells funny to me as well.
The pressure head should be more than enough to allow the fuel to flow.
I was thinking about water contamination blocking the filter but usually only happens with the felt filters

There is nothing fishy about it. Some tanks are literally even with the top of the carb the pressure head is almost zero. All fluids have some sort of surface tension. Gasoline is very low compared to water

From the petroleum institute of America

"The surface tension of water is approximately 72.3(10 -3 ) N/ml, whereas the surface tension of gasoline is 21.60 (10 -3 ) N/ml [24] .Dec 24, 2020"

When the pore size of the filter element is small enough at a certain point the fuel will stop flowing. Usually around 1/2 full. What also happens is the fuel stops from fuel starvation and they pull off the fuel line which breaks the surface tension and then capillary action starts and fuel flows freely then they put the fuel line back on and after the float bowl fills the flow rate drops to zero again and surface tension stops flow through the filter and engine dies in a few minutes. most riders have the tank a little higher so you can usually but not always use a paper filer on a gravity fed rider. I have had mowers come in the shop that have been to dealerships with real mechanics and not a hack like me with surging and fuel delivery problems from the wrong filter. They usually have new carbs and coils and fuel lines too.

bertsmobile1 said:

...but usually only happens with the felt filters

Click to expand...

Two ways we can answer this....

• That's exactly the way I felt.
• Stop groping those filters before installation.