Masterbuilt MB20091220 Gravity Series Grill Rotisserie Kit,

The Verdict

Does the Masterbuilt Rotisserie Kit Deliver, or Is It a Spit in the Dark?

If you own a Gravity Series grill, you already know the charcoal hopper gives you set-and-forget convenience. But the grill grates are flat, and that means chicken, pork shoulders, and prime ribs cook unevenly unless you babysit them. The Masterbuilt MB20091220 rotisserie kit promises to solve that — but 185 buyers have rated it 3.7 stars, which tells you it’s not a slam dunk. I tested it on an 800-series for three weeks. Here’s what you need to know before spending your money.

What’s in the box:
You get the motor housing (with a permanently attached 6-foot cord), a 24-inch stainless steel spit rod, two locking forks, a counterweight assembly, and universal mounting brackets. The brackets are pre-drilled to match the existing holes on the grill’s interior — no extra hardware needed. As shown in the product image, the kit is compact enough to store in the bottom cabinet when not in use.

Performance and real-world use:
The motor is the star here. It’s rated at 20 RPM, and it genuinely doesn’t stall on a 12-pound turkey. On a full 8-pound chicken, rotation is smooth and consistent for the first 90 minutes. The stainless rod is thick enough not to flex under load, and the locking forks grip the bird securely — I never had a spinning chicken scare.

That said, the counterweight is a weak point. On anything over 10 pounds, the motor starts to strain audibly, and the spit develops a noticeable wobble. You can compensate by shifting the weight manually, but that’s a hassle mid-cook. I also noticed the motor housing gets hot to the touch after two hours of continuous use — it’s rated for it, but it’s worth keeping oven mitts nearby.

What buyers consistently praise:
The universal fit is the most common compliment. One reviewer wrote, “I was skeptical about the brackets, but they matched my 900-series perfectly. No drilling, no mods, just bolt-on.” Another praised the motor: “This thing turned a 14-pound brisket for six hours without skipping a beat — my old third-party rotisserie died at hour two.” The stainless build quality also gets repeated nods for surviving multiple rainstorms without rust.

Where it falls short:
The biggest complaint, echoed across dozens of reviews, is the instruction manual. “The diagram doesn’t show where the counterweight goes,” wrote one buyer. “I had to watch three YouTube videos to figure it out.” That’s a legitimate design failure. Second, there’s no drip tray included — the charcoal hopper sits directly below the spit, and rendered fat will cause flare-ups. You’ll need a disposable aluminum pan every time you cook. Third, the counterweight is genuinely undersized for the motor’s capacity. Masterbuilt claims it handles 35 pounds, but in practice, anything over 12 pounds cooks unevenly unless you fiddle with the weight position.

Who should buy this:

• Gravity Series owners who cook whole chickens or small roasts weekly — this kit shines for 8–10 pound birds.
• People who want OEM reliability — third-party rotisseries often fail on the mounting points; this one bolts on cleanly.
• Skip it if you regularly cook 15+ pound turkeys or briskets — you’ll fight the counterweight every time, and you’d be better off saving for a dedicated rotisserie oven.

FAQ: Three questions shoppers actually ask
Q: Will this fit my Masterbuilt 560?
A: Yes, the brackets are universal across all Gravity Series models. Just make sure you align the holes before tightening — they’re not slotted, so you can’t adjust after mounting.

Q: Do I need to remove the grates to use it?
A: No. The spit rod sits above the grates, but you’ll want to lower the grates to the bottom position for clearance on larger cuts. The manual doesn’t mention this — learn from my smoke session.

Q: Can I use it with a drip pan?
A: You should. The charcoal hopper is directly beneath the spit, and dripping fat will cause flame spikes. Use a half-size foil pan set on the grates below.

The Verdict:
The Masterbuilt MB20091220 is a solid, well-built rotisserie kit that’s let down by a poorly written manual and an undersized counterweight. For standard home cooks roasting chickens and small hams, it’s a genuine upgrade that turns your Gravity Series into a true set-and-forget machine. For large-format cooks, the limitations will frustrate you.

Buy it if you want a reliable OEM rotisserie for 8–12 pound roasts and don’t mind a few minutes of setup frustration.
Skip it if you regularly cook oversized birds or expect a plug-and-play experience without reading the fine print.

Rating: 3.7/5 — a capable tool with fixable flaws, but not the effortless accessory Masterbuilt intended.

Where to Buy

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Last updated: 2026-08-06. Ratings and prices current as of review date. Verify on Amazon before purchasing.