Hey guy thanks for all the great help my mc28 has been a blast love it.

Just one question I have read the threads of all the serial / vins and no one has asked how to tell how old your engine is by the Vin number. If someone could that would be awsome looked everywhere but no luck for me.

Any thoughts Andy
Thanks again .

Thanks for the kind words, krull.

Difficult to say, regarding the age by the VIN. The problem is a lot of swaps have taken place over the 28 years the NSRs have been around!

Here's a basic run down for you:

All NSR250 crankcase castings are designated MC16E. (Not all NSR250 cases, notably many HRC ones, are stamped though.)

1987 MC16:

Solid engine mounts | crank with separate centre seal | hex barrels/heads with 90° alloy outlets & additional small brass hose unions | small exhaust port windows & RC Valve flaps

1988 MC18 R2J/R4J SP:

Rubber engine mounts | crank with separate centre seal | hex barrels/heads [top head with steel spigot] | large exhaust port windows & RC Valve flaps.

1989 MC18 R5K/R6K SP:

Rubber engine mounts | crank with integral centre seal | hex barrels/heads [top head with steel spigot] | large exhaust port windows & RC Valve flaps.

90~93 MC21 R/SE/SP:

Rubber engine mounts | crank with integral centre seal | round barrels/heads [top head with steel spigot] | angled exhaust port windows & RC Valve flaps [for reduced piston ring wear].

In 1991 the crankcases and oil pump were redesigned, for additional crankshaft lubrication on some models. In 1992, the modification was carried over to all engine variants.

94~97 MC21 R/SE/SP:

Same as late MC21.
_________________
Andy.
NSR-WORLD.COM

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