5.7 Inch Motor Gasket — #221
5.7-inch motor mounting gasket. Match motor diameter, mounting arrangement and the original gasket before fitting.
This replacement vacuum motor is the AMETEK Lamb 117939 used in select MD central vacuum power units. It is a new motor, not rebuilt, and is listed for MD M850 and M850H 120V models.
Available from Ace Vacuums, with help matching parts to your MD central vacuum system at our Fairfax and Leesburg, VA showrooms.
The 117939 Vacuum Motor is a replacement motor for select MD central vacuum power units. This AMETEK Lamb motor is listed for MD M850 (120V) and MD M850H (120V) models and may also be marked 7939 or 11-7939.
Specifications provided for this motor include a 3-stage design, 5.7 inch bottom diameter, 8 inch height, 3-1/2 inch bolt height, 138.6 inch waterlift, 101.2 CFM, 458 air watts, and 13.6 amps. It only replaces the 117939 motor.
This part is listed as the match for these MD central vacuum power units:
Check the model number on your power unit label before ordering. Our team can confirm the match if you are unsure.
| Specification | Details |
|---|---|
| Brand | AMETEK Lamb |
| Motor number | 117939 |
| Part number | 199R |
| Fan stages | 3 |
| Bottom diameter | 5.7 in |
| Voltage | 110-120 |
| Hertz | 50-60 |
| Height | 8 in |
| Bolt height | 3-1/2 in |
| Waterlift | 138.6 in |
| CFM | 101.2 |
| Air watts | 458 |
| Amps | 13.6 |
| Fits MD models | MD M850 (120V), MD M850H (120V) |
| Compatibility note | Includes AirMaster, Modern Day and SilentMaster |
| Authorized Dealer | Ace Vacuums |
When you purchase from Ace Vacuums, you receive:
The AMETEK Lamb 117939 Vacuum Motor for MD Central Vacuum is available online and in-store through Ace Vacuums.
Call 703-997-9292 (ext. 1 Fairfax, ext. 2 Leesburg).
This replacement vacuum motor is the AMETEK Lamb 117939 used in select MD central vacuum power units. It is a new motor, not rebuilt, and is listed for MD M850 and M850H 120V models.
Available from Ace Vacuums, with help matching parts to your MD central vacuum system at our Fairfax and Leesburg, VA showrooms.
The 117939 Vacuum Motor is a replacement motor for select MD central vacuum power units. This AMETEK Lamb motor is listed for MD M850 (120V) and MD M850H (120V) models and may also be marked 7939 or 11-7939.
Specifications provided for this motor include a 3-stage design, 5.7 inch bottom diameter, 8 inch height, 3-1/2 inch bolt height, 138.6 inch waterlift, 101.2 CFM, 458 air watts, and 13.6 amps. It only replaces the 117939 motor.
This part is listed as the match for these MD central vacuum power units:
Check the model number on your power unit label before ordering. Our team can confirm the match if you are unsure.
| Specification | Details |
|---|---|
| Brand | AMETEK Lamb |
| Motor number | 117939 |
| Part number | 199R |
| Fan stages | 3 |
| Bottom diameter | 5.7 in |
| Voltage | 110-120 |
| Hertz | 50-60 |
| Height | 8 in |
| Bolt height | 3-1/2 in |
| Waterlift | 138.6 in |
| CFM | 101.2 |
| Air watts | 458 |
| Amps | 13.6 |
| Fits MD models | MD M850 (120V), MD M850H (120V) |
| Compatibility note | Includes AirMaster, Modern Day and SilentMaster |
| Authorized Dealer | Ace Vacuums |
When you purchase from Ace Vacuums, you receive:
The AMETEK Lamb 117939 Vacuum Motor for MD Central Vacuum is available online and in-store through Ace Vacuums.
Call 703-997-9292 (ext. 1 Fairfax, ext. 2 Leesburg).
This motor is listed for MD M850 (120V) and MD M850H (120V).
No. It is a brand new motor, not rebuilt.
It only replaces the 117939 motor.
Yes. It may say 7939 or 11-7939.
The listed specs are 110-120 volts, 50-60 hertz, and 13.6 amps.
The record lists signs such as a mini breaker popping, electrical smell, excessive blue sparks from the motor top, a click with no startup, shutting down on its own and working later, or reaching its expected life.
Yes. The 117939 motor has carbon motor brushes that can be replaced.
If you have an MD M850 (120V) or MD M850H (120V), this is the listed motor. If your model is different, confirm the exact power unit model and motor number before ordering.
Check real-time traffic and travel time from your location in VA, DC, or MD.
Address: 11110 Main St, Fairfax, VA 22030
Landmark: Opposite Havertys Furniture Store
Best for: Bethesda, Potomac, Arlington, NW Washington D.C.
Address: 300 Fort Evans Rd NE, Suite 104, Leesburg, VA 20176
Landmark: Next to Home Depot in Leesburg
Best for: Ashburn, Sterling, Frederick MD, Loudoun County
In-stock merchandise generally ships from our Leesburg, Virginia location within 3–5 business days. Processing time is separate from carrier transit time and is not a guaranteed delivery date. Weekends and holidays can affect timing. Special-order, backordered or unavailable items may take longer; contact us to confirm timing before purchase when a deadline matters.
Shipping options and charges are shown at checkout. After dispatch, follow the carrier's tracking updates. Weather, carrier delays, order verification and inventory confirmation may affect delivery. Inspect packages promptly and retain packaging if there is damage or an incorrect or missing item.
Eligible unused items have a 30-calendar-day return request window for refunds or exchanges, measured from delivery or in-store purchase. Return authorization is required. Final-sale exclusions, the 15% restocking fee for change-of-mind returns and shipping responsibilities are explained in our Return and Refund Policy. That policy is the governing source for return eligibility and fees.
For shipping or return help, email sales@acevacuums.com or call 703-997-9292.
Updated September 27, 2026. Request a return for an eligible unused item within 30 calendar days of delivery (or purchase for items collected in store). Eligible returns may be refunded to the original payment method or exchanged, subject to availability. The same 30-day request window applies to both refunds and exchanges; there is no separate seven-day or 15-day refund deadline.
Items must be unused, clean, complete and in their original packaging with all accessories, manuals and proof of purchase. Contact sales@acevacuums.com or 703-997-9292 before sending anything back. Include your order number, item and reason for return. We will confirm eligibility, charges and return instructions. Unapproved or cash-on-delivery returns are not accepted.
For an approved change-of-mind return, a 15% restocking fee applies to the returned merchandise price. Original shipping charges are not refundable and the customer pays return shipping. These charges do not apply to an approved return caused by our shipping error or a damaged/defective item claim. Contact us first so we can arrange the appropriate remedy and shipping instructions. Do not assume a prepaid label is included.
Air purifiers; discounted, clearance, trade-in, holiday-sale and price-matched purchases; gift cards; custom or special-order products; electrical parts; used or installed items; opened cleaning solutions; and used bags, filters, belts or other consumables are not eligible for change-of-mind returns. Other items clearly marked final sale at purchase are also excluded. An opened box alone does not disqualify an otherwise eligible unused, complete item, but consumables and cleaning solutions must remain unopened.
Inspect your order promptly and contact us as soon as you discover a problem, with your order number and photos where helpful. Keep the packaging. Change-of-mind exclusions and deadlines do not remove applicable defect, warranty, recall or statutory rights. Warranty coverage requires evaluation under the manufacturer's terms; dealer status does not guarantee free repair. Recalled products must follow the manufacturer's recall process.
After we receive and inspect the return, we will notify you of approval or the reason it cannot be accepted. Approved refunds are issued to the original payment method within 10 business days of approval; your bank may take additional time to post them. Contact us if more than 15 business days have passed since approval. Exchanges require authorization and replacement availability; any price difference and applicable charges will be explained before processing.
This policy applies to online and in-store purchases. We will honor more favorable written return terms provided with an earlier purchase. Applicable consumer rights remain unaffected. Where the European Union 14-day cancellation right applies, customers may cancel or return eligible orders within 14 days of receipt, subject to applicable legal exceptions, without giving a reason.
Selected maintenance or companion parts for this repair category. Match the original motor, board or component number before ordering.
Match the installed part number and connector. Electrical wands, powerheads and hose handles are not universally interchangeable. Round tools may need an adapter on proprietary handles. Hide-A-Hose valve series and RF generations have separate compatibility requirements. Select the exact variant on the product page.
5.7-inch motor mounting gasket. Match motor diameter, mounting arrangement and the original gasket before fitting.
Maintenance sheets for routine central vacuum hose and pipe care. Follow the label and system instructions; not a substitute for repair of a blockage or damaged system.
Match the full power-unit model, production version, bag collar and filter dimensions. Cyclonic, disposable-bag and permanent-filter systems use different supplies. A similar size or shared brand name is not enough to confirm fit. If a matching supply is not shown, send us the model label and a photo of the old bag or filter. Shop central vacuum bags & filters
For 25+ years, Ace Vacuums has filled the gap left by big-box retailers. We provide the expert repairs, warranty support, and genuine OEM parts that Amazon and Walmart simply don't offer. From free estimates to same-day service, we are your local alternative for professional home care solutions.
Conveniently serving Washington D.C. and Maryland (Montgomery & Prince George's Counties). Our showrooms are just 20 minutes from DC and 10 minutes from Tysons Corner.
Hablamos Español — Service in English & Spanish.
Serving Zip Codes: 20147, 20176, 22030, 22031, 20151, 20190, 22102, 22314, 20110, 20148 & surrounding areas. All repairs performed by certified technicians using genuine parts.