StainOut 71-502 Big Mouth™ High Heat Injection Sprayer with Rear Fill Port | GTIN 865183000151

The StainOut Systems 71-502 Big Mouth™ Injection Sprayer is a professional inline chemical injection sprayer designed for carpet cleaning, upholstery cleaning, tile and grout cleaning, and restoration work. Built around a rugged 5-quart rotomolded bottle with a large rear fill opening, the 71-502 offers reliable chemical application while reducing operator fatigue and refill time.

Compatible with most portable carpet extractors and truckmounts operating from approximately 30–1000 PSI, the StainOut 71-502 automatically injects concentrated cleaning solution into the water stream, eliminating the need for traditional pump-up sprayers.

Professional Features 

• Heavy-duty 5 Quart Big Mouth™ rotomolded bottle
• Large rear fill opening for fast chemical refills
• High temperature compatible
• UV dye compatible
• 30 to 1000 PSI operating range
• Professional ergonomic pressure gun
• Heavy-duty stainless steel wand
• Anti-drip spray jet
• 8006 Brass TeeJet spray tip
• Brass & stainless suction strainer
• Excellent filtration system
• Viton chemical-resistant seals
• 7-inch comfort foam grip
• 2-inch heavy-duty Velcro bottle strap
• Wide stable base helps prevent tipping
• Translucent bottle for easy chemical level monitoring

Why Rotomolded Bottles Outlast Blow-Molded Bottles

Not all injection sprayers are built the same. While many economy injection sprayers use thin-wall blow-molded bottles, the StainOut 71-502 features a heavy-duty rotomolded polyethylene bottle designed for years of commercial service.

Rotational molding allows the bottle walls to be substantially thicker than typical blow-molded containers. The result is a stronger bottle with improved impact resistance, excellent resistance to stress cracking, and a much more rigid structure that stands up to the daily abuse of professional carpet cleaning. Rotomolded products are commonly selected for applications where thicker walls, durability, and long service life are important.

Professional cleaners frequently load their sprayers into vans, trailers, and truckmounts, where they are exposed to vibration, chemicals, dropping, dragging, and years of repeated use. Thin blow-molded bottles can eventually become brittle or develop cracks around high-stress areas after repeated commercial use.

By comparison, the StainOut rotomolded bottle is built with longevity in mind. Many owners report using the same bottle for many years, and it is not uncommon for the bottle to outlast the rest of the sprayer assembly.

Rotomolded Bottle Advantages

• Much thicker wall construction
• Outstanding impact resistance
• Excellent resistance to environmental stress cracking
• More durable around the bottle neck and fittings
• Less likely to crack if accidentally dropped
• Designed for years of commercial service
• Often eliminates the need for future bottle replacement

If you clean professionally every day, investing in a rotomolded bottle can reduce downtime, replacement costs, and the inconvenience of replacing worn or cracked bottles over the life of your equipment.

Why Professionals Prefer the Big Mouth Design

Unlike older injection sprayers that require removing the complete spray assembly to refill the bottle, the Big Mouth™ design incorporates a large rear fill port with a tethered cap. This allows operators to quickly refill chemicals while leaving the spray gun attached, reducing downtime on commercial cleaning jobs.

The rotomolded polyethylene bottle is significantly stronger than many molded containers, resisting dents, cracking, and chemical attack while remaining lightweight enough for all-day operation.

The History Behind the StainOut 71-502

Many professional carpet cleaners immediately recognize this sprayer because its design originated with the famous Mytee injection sprayers that became industry standards for decades.

After the Mytee company changed ownership, members of the LaBarbera family continued designing professional cleaning products under the StainOut Systems name. The StainOut 71-502 carries forward the same proven injection sprayer concept while incorporating numerous improvements including a stronger bottle, high-temperature capability, improved filtration, Viton seals, stainless steel components, and UV compatibility.

If you've been searching for a replacement for a Mytee 9500 injection sprayer or simply want the latest evolution of this proven design, the StainOut 71-502 is an excellent choice.

How an Inline Injection Sprayer Works

The StainOut 71-502 connects directly to your extractor's high-pressure solution hose. As water passes through the injector, concentrated cleaning solution is automatically drawn from the 5-quart bottle and mixed into the water stream before being sprayed onto the carpet or hard surface.

This allows operators to apply consistent preconditioning chemicals without carrying separate pump-up sprayers or repeatedly mixing solutions throughout the day.

Approximate Injection Ratios

Actual ratios vary depending upon solution viscosity, pressure, hose length, and operating temperature.

Typical Applications

• Residential carpet cleaning
• Commercial carpet cleaning
• Restaurant carpet maintenance
• Apartment turnover cleaning
• Hotel housekeeping
• Tile & grout cleaning
• Stone cleaning
• Restoration cleaning
• Traffic lane preconditioning
• Truckmount carpet cleaning systems
• Portable carpet extractors

Specifications

Frequently Asked Questions

Can this replace my older Mytee injection sprayer?

Yes. Many professionals purchase the StainOut 71-502 specifically as a replacement for older Mytee injection sprayers because the design evolved from the same product family while adding several modern improvements.

Will it work with my portable extractor?

The 71-502 is compatible with most professional extractors and truckmounts operating between approximately 30 and 1000 PSI.

Does it include metering tips?

Current factory production includes the yellow metering tip. Beginning in 2024, the manufacturer discontinued including the assortment of additional metering tips that had previously shipped with some units.

Can I use high-temperature solution?

Yes. The StainOut Big Mouth is designed for high-temperature operation and incorporates Viton seals and stainless-steel components for long service life.

Specifications and included accessories are subject to change without notice. Product images may show optional accessories or previous production versions. Always follow the cleaning chemical manufacturer's instructions and verify surface compatibility before use.

Watch: Injection Sprayer Maintenance & Troubleshooting

Keep your StainOut 71-502 operating like new by performing a few simple maintenance procedures. In this exclusive Steam-Brite training video, Donald Cook demonstrates proper care, cleaning, and troubleshooting techniques that can dramatically extend the service life of your injection sprayer.

In this video you'll learn:

• How to properly flush the sprayer after every job
• How to prevent clogged injectors and spray tips
• How to clean the internal strainer
• How to inspect seals and fittings for leaks
• Common reasons an injection sprayer stops drawing chemical
• Preventive maintenance tips to maximize service life

Steam-Brite Tip: Always flush the injection sprayer with clean water after using presprays, degreasers, or specialty chemicals. Routine flushing helps prevent chemical buildup, clogged injectors, and premature seal wear, keeping your sprayer performing at its best for years of dependable service.

The Original Inventor's Perspective

The inline carpet cleaning injection sprayer offered here has a unique history. Steam-Brite founder Donald Cook developed the original concept in 1981 to provide professional carpet cleaners with a faster, more consistent way to apply prespray chemicals without the constant pumping and refilling associated with conventional pump-up sprayers.

Over the decades, the design evolved through several manufacturers and product generations, eventually becoming one of the most widely recognized professional inline injection sprayer designs in the carpet cleaning industry. The current StainOut 71-502 Big Mouth™ Injection Sprayer continues that legacy while incorporating modern improvements such as a heavy-duty rotomolded bottle, large rear fill opening, stainless-steel components, Viton seals, and improved durability.

Having been involved with this design since its introduction, Steam-Brite offers customers more than just a product—we provide decades of real-world experience, technical support, maintenance videos, replacement parts, and practical advice to help keep these sprayers operating reliably for years.