1976 KAWASAKI KX400

Gorgeous Frame-Off Restoration

Ultra-Rare Investment-Quality Big Bore MX AHRMA Ready

The Golden Era of MX

Offered here is one of the rarest production motocross motorcycles of the 1970s—a beautifully restored 1976 Kawasaki KX400, the final evolution of Kawasaki's first-generation open-class motocross machine.

The 1976 KX400 represents the end of an important chapter in Kawasaki history. After this model, Kawasaki discontinued its production big-bore motocross bike for 1977, 1978, and 1979 before introducing the legendary Uni-Trak KX420 in 1980. As a result, the 1976 KX400 stands alone as the final and most refined version of the original series.

In our estimation, fewer than 1,000 examples were sold in the United States, making these dramatically rarer today than comparable open-class machines.

We've specialized in restoring vintage big-bore motocross motorcycles since 2011, and this is only the second 1976 KX400 we've acquired in over fifteen years.

Proven Racing Heritage

The factory version of this motorcycle was raced by motocross legends Jimmy Weinert and Gary Semics during the 1976 AMA 500cc National Championship season.

Although Kawasaki narrowly missed the championship that year, Gary Semics won the final three AMA National rounds in succession, proving beyond any doubt that the KX400 was a legitimate National-winning platform. Kawasaki riders also enjoyed tremendous success in amateur competition throughout New England, the South, and the West Coast, making the KX400 one of the most respected open-class motocross machines of its era.

History of This Motorcycle

This motorcycle comes from an outstanding Texas vintage motocross collection housed in a custom-built museum-style building.

The previous owner originally restored the bike as an AHRMA race machine, performing a complete engine rebuild and riding it only a handful of times afterward. Based on the condition of the fuel tank and overall machine, we estimate the engine had approximately three to four hours of use following that rebuild before it came into our possession.

Rather than simply cleaning it up, we elected to take the restoration to the next level.

The motorcycle was completely disassembled to the bare frame and treated to the same level of detail normally reserved for factory race machines after a National event.

Our Restoration

The motorcycle was stripped to the frame.

The frame and swingarm were sandblasted and refinished in the correct gloss black.

Every nut, bolt, bearing, bracket, and component was inspected.

Anything that did not meet our standards was replaced or restored.

Approximately 40 hours of labor were invested by our restoration department, while the previous owner had already invested approximately 30 hours into the mechanical restoration and engine rebuild, resulting in roughly 70 total hours devoted to creating the motorcycle you see today.

Highlights

• Professionally rebuilt 400cc two-stroke engine

• Compression tested and verified & Cylinder inspected with borescope

• Starts easily and runs exceptionally well

• Approximately 43 horsepower

• Wheelies effortlessly on command

• Frame-off restoration

• Original frame professionally refinished

• Original swingarm refinished

• Engine cosmetically restored

• Cases refinished

• Cylinder and head refinished

• Side covers refinished

• Carburetor professionally rebuilt and cleaned

• Original airbox restored and refinished

• New air filter installed

• Intake boot in excellent condition

• Original triple clamps vapor honed

• All bearings cleaned and freshly greased

• Extensive new hardware throughout

• New gold drive chain

• New rear sprocket

• New countershaft sprocket

• Rear brake serviced

• Hubs refinished

• Original wheel set retained due to excellent condition

• Fork lowers polished

• New fork seals

• New fork sliders

• Excellent fork tubes with no pitting

• New Dunlop front tire and tube

• New 120/90-18 Dunlop rear tire

• Nolene Racing rear shocks

• Oversized foot pegs

• Updated modern rear brake pedal

• Renthal handlebars

• Kawasaki crossbar pad

• Motion Pro throttle

• ODI grips

• MSR quick-adjust clutch and brake perches

• New control cables

• Nightmare Racing front fender

• Nightmare Racing rear fender

• Nightmare Racing side panels

• Nightmare Racing front number plate

• Custom graphics

• Beautiful restored fuel tank (has a little wear from 3 races)

Since completion of our restoration, this motorcycle has not been ridden off-road.

Condition

Overall, this KX400 presents beautifully and is suitable for a serious vintage collection, museum display, AHRMA competition, or investment.

As with any honestly represented vintage race motorcycle, we want to disclose the following:

• Small scratch on the fuel tank from limited riding after the previous restoration

• Minor rub marks where the seat contacts the tank

• A few tiny paint chips near the front of the tank by the steering stem

• Typical small dents in the expansion chamber from prior riding

• Seat foam has been replaced and remains excellent

• Seat cover has one very small tear near the front

• Countershaft sprocket cover is currently missing. Mounting tabs are intact and undamaged. We were unable to locate a replacement during the restoration.

If the new owner intends to display the motorcycle, we can install a brand-new seat cover at minimal additional cost. If you intend to race it, the existing cover is perfectly serviceable.

Investment Opportunity

Finding a 1976 KX400 is difficult.

Finding one restored to this level is almost impossible.

To duplicate this motorcycle today, beginning with a typical unrestored example, would easily require well over $10,000 in restoration labor plus thousands more in parts, assuming you could even locate a suitable project.

These motorcycles continue to become harder to find every year, and we believe they represent one of the most collectible Japanese motocross bikes of the 1970s.

Whether your goal is vintage racing, museum display, or long-term investment, this KX400 checks every box.

When it comes to restoring rare vintage big-bore two-strokes, Kaplan Cycles has become the nation's leading specialist.

Please review all photographs carefully, watch the walk-around video, and contact Junior at 860-454-7024 or any member of our sales staff with any questions.

Thank you for your interest, and as always...

God Bless America!

WHY SHOULD YOU BUY FROM KAPLAN? WHAT DO YOU GET?

“You are buying from the Kaplan Cycles Family. We are not just another big auction house. We are family-owned and operated and have been buying, servicing, and selling motorcycles since 1975. You will work directly with Ken Jr., Ken Sr., and/or one of the 30+ experts on our team. We provide museum-quality, white-glove concierge service from start to finish. Every motorcycle we sell is inspected, serviced, and supported by our team, and we stand behind it after the sale. You’re not on your own — we back what we build and what we sell.

With over 17,000 units sold and still 100% positive feedback, we are the best stress-free buying experience you can have. From the first call to delivery at your door, we will handle it all — because vintage motorcycles deserve support, and so do you.

With every bike we curate you get:
• museum-level inspection & preservation services
• every machine is professionally evaluated, serviced, & rotisserie detailed
• all critical systems are checked, adjusted, or renewed
• you get professional setup, tuning, and delivery prep
• done by the best experts in the industry — we ride and restore every day
• you get post-sale phone support
• you get white-glove, insured, always-enclosed shipping to your door anywhere in the country

You’re buying from Kaplan Cycles at the New England Motorcycle Museum, one of the largest vintage motorcycle collections in North America. Free museum tours and tickets are included with every bike sold. With every bike you purchase, a portion of the proceeds is used to support, continue, and improve the 501(c)(3) nonprofit New England Motorcycle Museum.

You don’t just win an auction — YOU are creating & helping to preserve motorcycle history, and you become part of our family, a Kaplan Cycles client for life.

We do not take new clients off the street.
We do not service bikes purchased elsewhere.
We only take new exclusive clients who purchase a motorcycle from us.

You get a guided purchase experience with, and from, the experts who care about the bike as much as you do. If there’s a problem, you don’t get ghosted. You call us — you will have our cell phone numbers — we will answer your call on weekends, and we will help make it right.

Auction platforms = listing only. No support. No accountability.

Kaplan Cycles = we stand behind what we sell.

You are buying museum-curated provenance. That means:
• expert evaluation
• documented condition
• professional presentation
• long-term preservation mindset

You’re not just buying a motorcycle — you’re buying a curated piece of motorcycling history.

From the #1 family in this business — Kaplan Cycles & the New England Motorcycle Museum.

Sincerely,

Ken Kaplan Sr.
12/28/2025”

AUCTION TERMS:

All motorcycles & vehicles are sold as-is where-is.

Kaplan Cycles guarantees all motorcycles are as-described. Please read the entire description and watch the entire video before bidding.

A non-refundable deposit is due immediately on purchase. PayPal or Credit Card is accepted for the deposit.

Cash (In-Person), Card (+3% fee), or Wire Transfer are our only accepted forms of final payment.

Full payment must be made within 7 days of auction close.

Your motorcycle must be picked up within 30 days of auction close. 

Exceptions are made only for international buyers OR buyers who have ALREADY made transport arrangements with a third party.

If a motorcycle is purchased and left here for longer than 30 days without written permission from Kaplan Cycles it will be resold. In the case of a re-sale, the owner will be entitled to a refund less storage fees ($25/ day beginning 30 days from auction close) ONLY if the motorcycle was paid in full on-time within the auction terms.

We always describe our motorcycles as accurately as possible.

You are purchasing a classic motorcycle. Even in cases where a bike may be in good running/ operating condition, new problems & idiosyncrasies can arise over-time from sitting or regular use.

If you have an issue with the motorcycle you’ve received, contact us within 24 hours of delivery and before leaving feedback so that we can address your concerns.

It is important you have at least a basic mechanical knowledge before purchasing and operating a classic motorcycle.

Due to our backlog, we cannot perform any additional service work or modifications on your motorcycle after the sale (ie; adding a light kit, different tires, etc.)

We respond quickly between the hours of 9am and 5pm EST, Monday - Friday

For our fastest service please call Ken Kaplan Jr directly at 860-471-0192

We will not charge out-of-state buyers sales tax.
Out of state residents will pay sales tax with their DMV. 

We are not a registering dealership. You will receive only the documents required to register your vehicle in your state.

In our listings, title status is always listed directly below the main description.

In some cases we will sell motorcycles without title or registration. In these cases we guarantee all motorcycles sold are free and clear. We will always provide a route to obtaining title. Generally in these cases, the motorcycle will be sold at a discount to accommodate expenses involved.

Documents are mailed via USPS priority mail with a tracking number. Please allow up to 14 days after payment in full for your documents to be processed and mailed.

Keys will be shipped with the motorcycle.

Warranty:

All Motorcycles sold "as is, where is" and Kaplan Cycles does not warranty any motorcycle sold. No express warranty and/or implied warranty are made by Kaplan Cycles. No statements by us give an implied warranty.

SHIPPING:

SEND US YOUR ZIP FOR A SHIPPING QUOTE!
WE WILL MAKE ALL ARRANGEMENTS!

We have the best shipping contacts in the nation who will provide the FASTEST transport times, have a perfect track record, and are always insured and ENCLOSED! All motorcycles are shipped WHOLE (roll-on, roll-off). We do not offer a pallet or crate service.

International shipping specialist contacts are available! They will assist in ground freight, customs clearance, and ocean freight to your country. International buyers will be required to work directly with our third party shipping contacts.

We strongly recommend you insure your motorcycle at the time of purchase.

PICKUP:

We require a 24 hour notice prior to pick-up. Please call us at 860-454-7024 during office hours Monday – Friday 9am – 5pm EST.

We will provide ramps, a dock for loading, and assistance to load for free.