1975 YAMAHA DT400 ENDURO

Museum-Quality Frame-Off Restoration

Completely Rebuilt Engine With All New Components

The Most Expensive DT 400 Restoration We Have Ever Done

Over $21,275 Invested in Restoration

If you’ve been searching for an exceptionally restored Yamaha DT400, take a close look at this one.

This 1975 Yamaha DT400 represents the most comprehensive — and most expensive — DT400 restoration we have ever completed here at Kaplan Cycles.

We have restored more Yamaha DT-series motorcycles over the years than anyone. Search “DT400 Kaplan Cycles” on YouTube and you’ll find an extensive collection of DT400 restorations, test rides, and builds completed through our shop.

We know these motorcycles. We rode them when they were new in the 1970s, we love them today, and whenever we have the opportunity to properly restore one, we take it seriously.

This particular DT400 received a multi-month, frame-off restoration totaling:

113.5 Hours of Shop Labor @ $150/Hour: $17,025
Parts Invested: Approximately $4,250
Total Documented Restoration Investment: $21,275

And that does not include the original purchase price or value of the motorcycle itself.

This was truly a labor of love.

COMPLETE ENGINE REBUILD

The heart of any DT400 is Yamaha’s legendary big-bore two-stroke single-cylinder engine, and this engine was completely rebuilt from the crankshaft up.

With approximately 12,500 miles, the engine was removed from the chassis and completely disassembled.

The engine cases were split, thoroughly cleaned, vapor-honed, refinished, and reassembled.

Engine restoration included:

• New crankshaft bearings

• New crankshaft seals

• Crankshaft inspected/trued

• Complete top-end rebuild

• Cylinder professionally bored

• New piston

• New piston rings

• New base gasket

• New cylinder-head gasket

• New spark plug

• New ignition components

• New clutch components

• New shifter-shaft seal

• New kickstarter seal

• New spark plug wire

• Carburetor completely rebuilt

• Carburetor cosmetically restored and refinished

• New fuel petcock

• New fuel lines

• New fuel drain/vent lines

• New intake boots

• New air filter

• Complete oil-injection-system service/rebuild

• Exhaust system removed, sandblasted, and refinished

• Silencer restored

• New exhaust gaskets

• New engine/exhaust mounting hardware where required

The engine cases, covers, cylinder, and associated components were also cosmetically restored.

The finished result is outstanding.

This is the tightest-running DT400s we have ridden. The engine feels exceptionally smooth and fresh, with the solid mechanical feel you would expect from a properly rebuilt motorcycle.

There are no weird vibrations, rattles, or loose mechanical characteristics commonly associated with unrestored 50-year-old machines.

Mechanically, this motorcycle feels exactly like a brand new DT400.

RESTORATION PERFORMED BY MARK OLSON

The restoration was completed by our senior technician, Mark Olson.

Mark has more than 45 years of professional motorcycle experience and has restored countless classic motorcycles during his career. He is semi-retired today and only works with us a couple of days per week, making motorcycles completed personally by Mark increasingly special.

His attention to detail on this DT400 is evident everywhere you look.

This was not simply cleaned up and repainted.

It was dismantled, inspected, rebuilt, refinished, and carefully reassembled component by component.

FRAME-OFF CHASSIS RESTORATION

Once the engine was completed, the motorcycle was stripped down for a comprehensive chassis restoration.

The frame was professionally stripped and powder-coated.

The swingarm was also professionally powder-coated.

From there, virtually every component was inspected, restored, rebuilt, refinished, or replaced where appropriate.

Once you powder-coat a frame to this standard, everything around it has to match — otherwise unfinished components immediately stand out.

That is why this project ultimately became so extensive.

FRONT WHEEL & BRAKE SYSTEM

Starting at the front of the motorcycle:

• Original wheel restored

• Original aluminum components cleaned and polished

• Front hub cleaned/restored

• Wheel bearings inspected/serviced

• New front brake shoes/pads

• New rim strip

• New inner tube

• Brand-new front tire

• Front wheel/tire professionally balanced

Balancing the front wheel on a vintage DT400 may sound excessive, but that is exactly the level of detail that went into this restoration.

FULL FORK RESTORATION

The front suspension was completely rebuilt.

The fork lowers were carefully refinished in the proper brushed-aluminum appearance, replicating how they would have looked when they left Yamaha.

Fork work included:

• Forks completely disassembled

• Fork lowers refinished

• Correct brushed-aluminum appearance

• Protective clear finish

• New fork seals

• New fork rubber components/boots

• Restored mounting hardware

The original factory reflectors remain intact.

COCKPIT, GAUGES & CONTROLS

Anyone familiar with vintage Yamaha enduros knows how difficult it is to properly restore the instrument mounting system.

The rubber gauge mounts and isolators are often deteriorated after five decades, leaving the instruments loose and moving around.

Mark spent considerable time sourcing the correct components required to properly restore the gauge mounting system.

The gauges now present beautifully and are securely mounted as they should be.

Additional cockpit restoration includes:

• Beautifully restored gauges

• New gauge mounting rubber components

• New mounting seals

• New handlebars

• Brand-new grips

• Original Yamaha mirror

• New throttle cable

• New front brake cable

• Restored switch housings

• Functional switches

• New lighting components/bulbs as required

• Brand-new headlight

• Restored triple-clamp hardware

The headlight bucket and headlight ears are straight and show no obvious evidence of crash damage.

BRAND-NEW YAMAHA YELLOW FUEL TANK

One of the visual centerpieces of the motorcycle is its brand-new reproduction fuel tank finished in classic Yamaha Competition Yellow.

The motorcycle received:

• New reproduction fuel tank

• New fuel cap

• New fuel petcock

• New fuel lines

The bright Competition Yellow tank against the restored black chassis gives this DT400 the unmistakable appearance that made Yamaha’s enduros legendary.

NEW SEAT & RESTORED UNDER-SEAT AREA

The seat is not merely recovered — it is a brand-new reproduction seat assembly.

It includes:

• New reproduction seat

• New seat mounting components

• New latch assembly

Underneath the seat, the restoration continues.

You will find:

• New battery

• Excellent original tool/battery tray

• Correct Yamaha rubber components

• New mounting hardware where required

• New decals

• Professionally sorted wiring harness

• Cleaned and restored electrical components

This is an area many restorations overlook.

Not this one.

UPGRADED PROGRESSIVE REAR SHOCKS

The original rear shocks were replaced with a brand-new set of Progressive Suspension shocks.

These provide improved damping and spring performance compared with worn original components.

Combined with the completely rebuilt forks, new tires, and restored chassis, the suspension performance is arguably better than what a 50-year-old original example could provide today.

FINAL DRIVE

The final-drive system was completely refreshed with:

• Brand-new oversized 520 chain

• New sprockets

• New chain-guide mounting hardware

• Restored/new associated hardware

The shifter is also new.

EXHAUST SYSTEM

The original-style exhaust system was comprehensively restored.

The exhaust was:

• Removed

• Sandblasted

• Completely refinished

• Reinstalled using new gaskets

• Installed with restored/new mounting hardware

The silencer was also rebuilt/refinished and fitted with new hardware.

The original exhaust heat shield and associated components present beautifully.

ELECTRICAL & LIGHTING SYSTEM

The electrical system was carefully sorted during restoration.

Features include:

• Working turn signals

• Working lighting system

• New bulbs where required

• Properly functioning switch housings

• New battery

• Professionally sorted wiring

• Original-style lighting components

Even the original reflectors on the rear taillight assembly remain intact.

The original taillight itself is in excellent condition.

ORIGINAL COMPONENTS RETAINED WHERE APPROPRIATE

This DT400 was not simply assembled from reproduction parts.

Where good original components could be preserved, they were restored and retained.

Notable original components include:

• Original frame

• Original front fender

• Original rear fender

• Original oil tank with original paint

• Original Yamaha mirror

• Original taillight assembly

• Original reflectors

• Original side-cover components & much more

The original silver front fender remains in very nice condition but does show a few minor age-related beauty marks.

The original rear fender also has a couple of small scratches/imperfections.

These are original components rather than freshly replaced reproduction pieces.

The original oil tank retains its original paint and was thoroughly cleaned during restoration.

ONE ITEM STILL BEING REPLACED

During the restoration, the original kickstand was misplaced while components were out for powder coating.

A replacement was ordered but the supplier sent a DT360 stand, which is too short.

We have ordered the correct DT400 kickstand, it will be installed before shipping.

Please contact us for the current status prior to purchase.

FOUR PAGES OF PARTS — EXTENSIVE DOCUMENTATION

The amount of documentation accompanying this restoration is extensive.

There are multiple pages of work orders and approximately four full pages documenting replacement parts alone, along with a substantial collection of receipts generated throughout the restoration.

The motorcycle was completed in several stages.

The engine was rebuilt first.

The chassis, frame, suspension, wheels, brakes, controls, electrical system, and remaining components were subsequently completed as the full frame-off restoration progressed.

The documented shop investment total labor is: 113.5 Hours × $150/Hour = $17,025

Parts: $4,250

TOTAL RESTORATION INVESTMENT: $21,275

Again, that figure does not include the cost or value of the original DT400 itself.

We do not expect to recover every dollar invested in a restoration like this.

At this level, these motorcycles are built as a labor of love.

LEGENDARY BIG-BORE TWO-STROKE

The Yamaha DT series helped define the dual-sport/enduro motorcycle category.

The DT400 combined Yamaha's large-displacement two-stroke single with genuine street legality and legitimate off-road capability.

Motorcycles like this simply aren't being built anymore.

A large-displacement, air-cooled, street-legal Yamaha two-stroke represents an era of motorcycling that has been gone for decades.

At 52 years old, this DT400 provides the opportunity to experience one of Yamaha's legendary enduros in a condition remarkably close to what these motorcycles felt like when they were new.

THE BOTTOM LINE

We have restored a lot of Yamaha DT motorcycles.

This is one of the best.

It represents an extraordinary amount of labor, parts, expertise, and attention to detail.

The frame is restored.

The suspension is restored and upgraded.

The brakes are restored.

The wheels are restored.

The tires and tubes are new.

The chain and sprockets are new.

The controls and cables have been restored or replaced.

The fuel system has been restored.

The oil-injection system has been serviced and rebuilt.

The electrical system has been sorted.

And most importantly, the engine has been completely rebuilt from the crankshaft up.

The result is a DT400 that feels remarkably tight, smooth, and fresh.

If you want a cheap DT400 project, there are other motorcycles out there.

If you want one that has already received the kind of extensive, no-expense-spared restoration that can consume hundreds of individual parts and more than 100 hours of professional shop labor, this motorcycle deserves serious consideration.

It would make an outstanding addition to a Yamaha collection, vintage enduro collection, motorcycle museum, or the garage of someone who remembers exactly what these legendary machines were like when they ruled the roads and trails in the 1970s.

FINANCING & SHIPPING AVAILABLE

We can assist with financing for qualified buyers and can arrange professional shipping anywhere in the continental United States.

International shipping assistance may also be available.

For additional information, photographs, restoration documentation, or to discuss purchasing the motorcycle, contact:

Kaplan Cycles / New England Motorcycle Museum
Call Ken Junior: 860-454-7024

This is a truly special Yamaha DT400 and one of the most comprehensive DT restorations to ever come through our shop.

Thanks for looking, and God Bless America.

Vin - 501-00581

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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”

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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

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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.

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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.