Should there be any 'vacuum' detected before the fuel filter?

[texasgeezer]

Just finished a couple of days troubleshooting zero turn with partial loss of torque in heavy grass.

Problem was due to partial blockage of air into fuel tank that showed up only under heavy load.

Thinking that it was probably causing a lean fuel condition even under light load & just wasn't showing up.

I was wondering if a check for a vacuum condition before the fuel pump would be a good thing to do every now & then. It would be simple to put a 'T' in line & use a vacuum gauge to check for partial blockage.

Problem is I don't know if it is normal to have a little vacuum reading or not.

Does anyone know?

 

[kuboman]

Just finished a couple of days troubleshooting zero turn with partial loss of torque in heavy grass.

Problem was due to partial blockage of air into fuel tank that showed up only under heavy load.

Thinking that it was probably causing a lean fuel condition even under light load & just wasn't showing up.

I was wondering if a check for a vacuum condition before the fuel pump would be a good thing to do every now & then. It would be simple to put a 'T' in line & use a vacuum gauge to check for partial blockage.

Problem is I don't know if it is normal to have a little vacuum reading or not.

Does anyone know?

There should not be any vacuum ahead of the filter. If you have a vacuum then you either have a venting problem with the tank or a restriction in the line,

 

[texasgeezer]

Thanks, that is what I thought, but didn't have any experience with that subject. I tore my failing fuel cap apart & found about five internal parts were coated with a layer of crud that had been sucked in during the 260 hours of run time.

Guessing all the parts help reduce air pollution & probably help prevent fuel from coming out if the mower overturned.

After researching I've decided to put an in-line low fuel pressure gauge between the fuel pump & carburetor. Autozone has a gauge and kit with a 'lifetime' warranty for about $15 (Spectre 59013).

That should show either a weak fuel pump or blockage before the fuel pump. Might help to prevent damage to engine due to leaner running condition.