The S90 Crankcase Timeline
- Version 1 (Early)
- Right side
- Oil filter = access through bottom plate (blue circle below)
- Oil path = distinguished by oval passage from right case to right cover (purple circle)
- note the proper gasket
- Oil pump = geared pump (orange square) with oil pipe
- Left side
- Has a tensioner with an adjusting bolt. Note the bolt hole (green circle)
- The bottom right corner of the cover is squared off (red square)
- Part number = 11330-028-000
- Early or Late = Early
- Frame number 111,565 to 142,498 and 424,487 to 527,510
- Version 1.5?
- Note: depending on how you interpret the parts guides, it's possible there was a version of the crankcase that had the newer oil filter in the slot, but also kept the oval oil passage. If you have this version, please send us a picture! You've found an S90 Missing Link!
- Version 2 (Late)
- Right side
- Oil filter = change to the filter in slot (at frame #527,511, orange circle)
- Oil path = discontinue the oval oil passage (at frame #527,511)
- note the proper gasket
- Oil pump = continue with geared pump (orange square) but oil pipe is discontinued
- Left side
- Switch to the newer style tensioner, bolt hole is gone (red circle)
- Early or Late: Late
- Starts at frame number 527,511
- Version 3 (Late with New Pump)
- Right side
- Oil filter = continues with filter in slot
- Oil path = no oval oil passage
- Oil pump = switch to trochoid pump (at frame #677,884, green square)
- Left side
- Extra hole for left cover starts at frame #779,100 (blue square)
- Note: it's currently unclear to me why there's no distinct part number for the right crankcase at frame #677,884 to correspond to the switch in oil pumps, or for the left crankcase at #779,100 to correspond to the extra hole for the cover
- Important Note:
- If you have the Early style engine with the oil passage (purple) then you MUST use the exhaust rocker shaft with the restrictor. This limits the amount of oil flowing to the head, thus saving some for the crank. Putting a non-restricted shaft in an Early engine is VERY BAD!
Detail of the Chain Tensioner: Early engine
Detail of the Chain Tensioner: Late engine
Detail of the Early engine oil filter access plate and related parts
Any idea what engine number did away with the oval slot? I have an engine number s90e-479150 that does not have the oval slot. It has the casting for the oil pipe, but no threads in it and pipe.
ReplyDeleteCan you identify an engine number S00 2 E 2132804. The first zero might be a '9' but more likely not. It is a Honda 90 OHC engine with cast iron cylinder
ReplyDelete