1991 Honda NSR250R SE Engine

Description

Please note: The seller states that “This engine has not been started or run since it was modified and rebuilt. It does not come with a warranty.”

The seller has provided the following walkaround video:

Additional photos are available here for your perusal.

In the mid-to-late 1980s, the small-displacement race replica market in Japan was booming. Legions of bright-eyed young riders were lining up to fork over their hard-earned yen for competition-derived road-legal runners like Yamaha’s TZR250, Kawasaki’s KR-1, and Suzuki’s RGV250. Manufacturers on the island were battling it out on the race track and in showrooms in an ongoing arms race to produce the most trick race bike for the streets.

In 1985, Honda launched the NS250R MC11, laying the foundation for its line of quarter-liter oil-burners that followed. The NS featured a box-section aluminum frame and swingarm, disc brakes, full GP-style bodywork inspired by the RS250R factory race bike, Honda’s Astralight rims, and a liquid-cooled, 249cc, 90-degree V-Twin engine, two-stroke engine that made 45 hp (at 9,500rpm) and utilized the ATAC (automatically-controlled torque amplification chamber) power-valve system.

Come 1991, Honda split the base and SP models of the NSR250R with the introduction of the SE (Super Edition) model. They had all of the SP goodies (dry clutch, adjustable suspension, special livery) except for the magnesium wheels.

This example is engine #: MC16E1223593. According to the seller, “I purchased the motor in 2012 from a customer at Cycle Depot in Eagle Rock, CA. He had offered to sell this extra motor built by Harry Okuda. At the time I thought it was a really good deal, but I haven’t had time to put the motor to use.”

True mileage is unknown. The seller states that the engine has not seen any miles under his ownership.

Maintenance:
Per the seller, “recently I removed the cylinder head to inspect what was done to the crankcase. From my observation the crankcase wall has been polished and epoxied for higher compression in the crankcase chamber. The crankcase has some epoxy wall and drilled holes for the oil to be injected into the crank. The piston and piston rings are STOCK OEM specs. The cylinder head ports have also been polished. After inspection, I reinstalled the cylinder and head with new OEM base gaskets and head gaskets.The compression has been tested and passed. The top cylinder tested at 140 psi and the bottom cylinder tested 165 psi. The crankshaft is original OEM. The condition of the crankshaft seal is unknown.”

Modifications:
“This engine was built by famous two-stroke race engine builder & tuner by Harry Okuda. This motor has ported cylinder heads and ported crankcase with direct crank oil injectors. This is the last of his creation. The engine comes with the original dry clutch and KEIHIN carburetors 38mm flat slide twin carb (not OEM spec) upgraded to bigger spec. The flywheel had been lightened and modified for advance timing.”

Cosmetic Blemishes: please see the album up top for all known cosmetic blemishes. Here is a selection:

Currently located in Los Angeles, California this engine is offered on a Bill of Sale only. Have any NSR250R stories or questions about this listing? Let us know in the “Comments” tab!