The VMX-52PRO Engine was first produced in September of 2003 and released to the North and South American markets in November 2003. Some engines may have been introduced in Australia beginning in October 2003.

The engine remains largely unchanged as of June 2004 with production changes limited primarily to the crankshaft, front bearing and drive washer system.

There have been three different crankshafts used in the VMX-52PRO since inception.

All three crankshafts have the same 1/4 x 28 NF thread and use the same prop nut and prop washer. The drive washer (behind the prop) is different in some cases and so is the front bearing. The following information helps to identify the crankshaft type and the drive washer and front bearing that matches each of the different types of crankshafts. The most easily identifiable feature of each crankshaft is shown below in italic type.

Type A Crankshaft - Part #VXR-462050A
 -  Used in first production lot until approximately Oct-Nov 2003.
- Has a 7mm outside diameter (OD) where it passes through the front bearing.
- Is silver  in color on the back face and the back face has notches that run through the entire back disc.

Type B Crankshaft - Part #VXR-462050B
- Used in production from Oct-Nov 2003 through approximately Feb-March 2004
- Has a 8mm outside diameter (OD) where it passes through the front bearing
- Is black in color on the back face and the back face has notches that run only partially through the back disc

Type C Crankshaft - Part #VXR-462050C
- Use in production beginning in March 2004
- Has a 8mm outside diameter (OD) where it passes through the front bearing
- Has two flat shoulders  just ahead of the front bearing to engage with the thrust washer
- Is black or silver in color on the back face and the back face has notches that run through the entire back disc

The differences in Crankshafts also are matched with some changes to the front bearing and drive washer.

Type A CrankShaft with OD 7mm - #VXR-462050A
- requires Type A Front Bearing with inside diameter (ID) 7mm - #VXR-462055A
- requires Type A Drive Washer (cone shape inside) - #VXR-462070A

Type B Crankshaft OD 8mm - #VXR-462050B
- requires Type B Front Bearing with ID 8mm - #VXR-462055B
- requires Type B Drive Washer (cone shape inside) - #VXR-462070B

Type C Crankshaft OD 8mm with shoulders - #VXR-462050C
- requires Type B Front Bearing with ID 8mm - #VXR-462055B
- requires Type C Drive Washer with flats to engage with shaft shoulders - VXR-462070C