Lawnmower Running Issues

[Warstud]

I have a Troy Bilt 6.75 Lawnmower with a re-occuring running / starting issue . When it first started giving me trouble .... I drained out the fuel tank and put in new gas and it ran fine for a couple weeks .

The second time it gave me trouble I took off the Carburator and removed the bowl and soaked it Gas and then it ran great .

The other day it just wouldnt start .

Today I got it running on Sea Foam and tilting the mower on a 45 degree angle with the carb facing down . It's obviously a fuel issue ...... any idea what could be causing it ?

 

[spasm3]

Sounds like the float needs adjustment or cleaning.

Check needle seat.

 

[JohnnyG]

Pull out the main jet and get that little piece of dirt out, it'll run like new.

 

[fantastic]

Probably a good carb cleaning is in order (Taking it apart). That may be a new carb if yours is old or new gasket set for your existing one. If you use starting fluid does it start? If so then it's a fuel issue. I would start at the carb.

 

[MRC01]

Another way to test whether it's the carb is to put fresh gas into a hand spray bottle, set the nozzle to thin stream rather than wide spray. Remove the air filter to expose the intake throat and give a squirt of gasoline straight into it. Then start it. If it starts and you can keep it running by giving it a little squirt each time the engine slows down and is about to stop, then it's the carb. In other words, it means the engine has compression & spark, the only thing missing is fuel/air mixture.

 

[mk378]

With the carb removed check that gas flows freely out of the tank through the fuel hose. Briggs used some bad fuel hose that swells inside and becomes clogged.

 

[Oro_O]

Does it run ok once you get it started?

If it runs at least “acceptably” - I’d operate it with the recommended amount of Seafoam in the fuel and let it clean up any issues. It works very well at that and it has saved me MANY hours of carb work with old motorcycles and OPM over the years.

ETA: Chemtool B-12 also works great for this and is cheaper, though you already have the SeaFoam on hand.

 

[Cujet]

I’d operate it with the recommended amount of Seafoam in the fuel and let it clean up any issues. ETA: Chemtool B-12 also works great for this

If there is varnish, maybe. But no cleaning product will dissolve sand or dirt in the carb.

 

[Oro_O]

If there is varnish, maybe. But no cleaning product will dissolve sand or dirt in the carb.

Correct, but my point was it’s worth trying this first to potentially save a lot of labor and aggravation. It’s a first step.

It’s usually varnish and not foreign object obstruction that causes this. So a low-cost/no effort solution at first is usually better than jumping into a potentially more problematic carb tear-down. It’s the automotive equivalent of “take two aspirin and call me in the morning.”

 

[Warstud]

Does it run ok once you get it started?

If it runs at least “acceptably” - I’d operate it with the recommended amount of Seafoam in the fuel and let it clean up any issues. It works very well at that and it has saved me MANY hours of carb work with old motorcycles and OPM over the years.

ETA: Chemtool B-12 also works great for this and is cheaper, though you already have the SeaFoam on hand.

It seems to start normally most of the time then dies after a few seconds . I managed to keep it from stalling by tilting the mower but it ran rough then cleared up and I mowed the whole front yard . A couple hours later it will start but not stay running ..... even if I tilt the mower .

 

[Rmay635703]

It seems to start normally most of the time then dies after a few seconds . I managed to keep it from stalling by tilting the mower but it ran rough then cleared up and I mowed the whole front yard . A couple hours later it will start but not stay running ..... even if I tilt the mower .

If this thing is Cali compliant (last 20 years) or newer than 10 years you probably don’t have a choke, nor do you have an old school “primer” that dumps gas in the mower.

Our inverter generator was this way.

Only way it would start below 60F was if you tipped it until gas spilled out the carb. It was that way day 1.
If you didn’t do this you can pull and stall 20 minutes before it would run.

If you don’t replace the carb with a chinesium antique that has a choke your idea to tilt the thing should work to start it.

In other words it’s designed that way. Either work around it or replace the carb, they are all garbage

 

[97prizm]

I have a Troy Bilt 6.75 Lawnmower with a re-occuring running / starting issue . When it first started giving me trouble .... I drained out the fuel tank and put in new gas and it ran fine for a couple weeks .

The second time it gave me trouble I took off the Carburator and removed the bowl and soaked it Gas and then it ran great .

The other day it just wouldnt start .

Today I got it running on Sea Foam and tilting the mower on a 45 degree angle with the carb facing down . It's obviously a fuel issue ...... any idea what could be causing it ?

Possible fuel line collapse or dirt blocking flow.

 

[97prizm]

Possible fuel line collapse or dirt blocking flow.

Or fuel filter. I had an air filter get really dirty exhibit the same symptoms

 

[Dinoburner]

When it stops pull the spark plug and check spark. Have had a problem with a weak spark when it warms up. With good spark then fuel is the problem.

 

[Rmay635703]

Or fuel filter. I had an air filter get really dirty exhibit the same symptoms

If it smells like raw gas, (easy to check the plug or remove the air filter)
my experience is you usually get too little fuel or bad gas.

Newer rigs are hard to keep running in cold humid weather

 

[Lubener]

I have a Troy Bilt 6.75 Lawnmower with a re-occuring running / starting issue . When it first started giving me trouble .... I drained out the fuel tank and put in new gas and it ran fine for a couple weeks .

The second time it gave me trouble I took off the Carburator and removed the bowl and soaked it Gas and then it ran great .

The other day it just wouldnt start .

Today I got it running on Sea Foam and tilting the mower on a 45 degree angle with the carb facing down . It's obviously a fuel issue ...... any idea what could be causing it ?

Had the same issue before on those engines.. The float could be sticking due to a corroded hinge pin for the float.

 

[JohnnyJohnson]

I'd run a couple tanks of gas through it with Techron fuel system cleaner.

 

[Warstud]

If this thing is Cali compliant (last 20 years) or newer than 10 years you probably don’t have a choke, nor do you have an old school “primer” that dumps gas in the mower.

Your right on .... no choke no primer and I'd have to tilt it to get it to start . A couple weeks ago though I took the Carb off and soaked it in gas and it started on the second pull for about four times and ran great .

 

[Warstud]

Or fuel filter. I had an air filter get really dirty exhibit the same symptoms

No fuel filter and the air filter is new . I'm gonna check that fuel line though

 

[Warstud]

Before starting it up today I decided to fill the fuel tank up before I started it (wasn't low on fuel ) it started on the second pull and ran fine . Fuel Line ?