OEM Engine Dimensions by Year

[Roostius_Maximus]

I'm going to post what 1985-01 production engines were intended to be as factory prepared parts.
Keep in mind that all engines have the piston .005"-.008" below the deck at top dead centre with the OEM .021" thick base gasket.
Some gasket kits base gaskets will alter this .002"-.003" but Cometic provides an aluminium base gasket for the 1989-01 models as standard replacement in their #C7020 set (Wiseco #5223) which is .012" thick.

Dimensions are given from top of the Cylinder ports measured from the deck down to the piston location.

[Roostius_Maximus]

1985

Head:
Casting:HF-1
Chamber depth:.010"
Plug reach:
Squish band width:
Squish distance
Gasket thickness:.045"
Gasket cc:
Chamber cc:



Cylinder:
Exhaust Port:44.25mm (1.742")
Opens in crank degrees:
Opens in piston position:
Duration:

Intake Transfers:62.75mm (2.470")
Opens in crank degrees:
Opens in piston position:
Duration:

Boost Port Opens:64mm (2.520")

Plenum Length (gasket surface to piston skirt):


Ignition:
Flywheel stamping: FP8153
Flywheel weight:527g
Flywheel Diameter:77.5mm
Flywheel width:39.5mm
Pickup trigger length:
Pickup trigger degrees:
Stator lock plate degrees:

Timing map:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:


Connecting Rod:
Length overall:178.45mm
Centre to centre:139mm
Housing bore rotating (big end):34mm
Rotating end width:19.75mm
Housing bore reciprocating (small end):
Reciprocating end width:23.98mm
Weight rotating end:
Weight reciprocating end:
Total weight:
Crank pin dimension: 26mm X 67.50mm
Crank bearing dimension:26X34X20
Crank pin weight:
Crank bearing weight:
Thrust washer dimension: 1.50mm X
Thrust washer weight:
Wrist pin bearing dimension:20X25X28
Wrist pin bearing housing bore:25mm
Wrist pin bearing weight:
Wrist pin weight:


Crankcase:
Cylinder sleeve recess Diameter:
Deck height (crank centre to gasket surface):
Right Case style:lite
Rear bushing bore:
Rear cylinder stud length:
Front cylinder stud length:


Clutch:
Width of basket:
Number of fibers:7
Number of steels:6
Main washer type:
Push rod length:202mm (7.950")
Lifter style:BB


Transmission:
Sprocket splines:6
Bearing at sprocket:91001-KA4-741
Engagement teeth:3
Ratio 1st:1.750
Ratio 2nd:1.388
Ratio 3rd:1.150
Ratio 4th:.955
Ratio 5th:.792
MS 1 tooth count:16
MS 2 tooth count:18
MS 3 tooth count:20
MS 4 tooth count:22
MS 5 tooth count:24
CS 1 tooth count:28
CS 2 tooth count:25
CS 3 tooth count:23
CS 4 tooth count:21
CS 5 tooth count:19
Bore of 2nd gear:
Crankshaft gear:
Clutch gear:
Primary drive ratio:

[Roostius_Maximus]

1986

Head:
Casting:
Chamber depth:
Plug reach:
Squish band width:
Gasket thickness:
Gasket cc:
Chamber cc:


Cylinder:
Exhaust Port:
Opens in crank degrees:
Opens in piston position:
Duration:

Intake Transfers:
Opens in crank degrees:
Opens in piston position:
Duration:

Boost Port Opens:

Plenum Length (gasket surface to piston skirt):


Ignition:
Flywheel weight:
Flywheel Diameter:
Pickup trigger length:
Pickup trigger degrees:
Stator lock plate degrees:

Timing map:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:


Connecting Rod:
Length overall:
Centre to centre:
Housing bore rotating (big end):
Housing bore reciprocating (small end):
Weight rotating end:
Weight reciprocating end:
Total weight:
Crank pin weight:
Crank bearing weight:
Thrust washer weight:
Wrist pin bearing weight:
Wrist pin weight:


Crankcase:
Cylinder sleeve recess Diameter:
Deck height (crank centre to gasket surface):
Right Case style:
Rear bushing bore:


Clutch:
Width of assembly:
Number of fibers:
Number of steels:
Main washer type:
Push rod length:
Lifter style:


Transmission:
Sprocket splines:
Bearing at sprocket:
Engagement teeth:
Ratio 1st:
Ratio 2nd:
Ratio 3rd:
Ratio 4th:
Ratio 5th:
MS 1 tooth count:
MS 2 tooth count:
MS 3 tooth count:
MS 4 tooth count:
MS 5 tooth count:
CS 1 tooth count:
CS 2 tooth count:
CS 3 tooth count:
CS 4 tooth count:
CS 5 tooth count:
Bore of 2nd gear:

[Roostius_Maximus]

1987

Head:
Casting:
Chamber depth:
Plug reach:
Squish band width:
Gasket thickness:
Gasket cc:
Chamber cc:


Cylinder:
Exhaust Port:
Opens in crank degrees:
Opens in piston position:
Duration:

Intake Transfers:
Opens in crank degrees:
Opens in piston position:
Duration:

Boost Port Opens:

Plenum Length (gasket surface to piston skirt):


Ignition:
Flywheel weight:
Flywheel Diameter:
Pickup trigger length:
Pickup trigger degrees:
Stator lock plate degrees:

Timing map:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:


Connecting Rod:
Length overall:
Centre to centre:
Housing bore rotating (big end):
Housing bore reciprocating (small end):
Weight rotating end:
Weight reciprocating end:
Total weight:
Crank pin weight:
Crank bearing weight:
Thrust washer weight:
Wrist pin bearing weight:
Wrist pin weight:


Crankcase:
Cylinder sleeve recess Diameter:
Deck height (crank centre to gasket surface):
Right Case style:
Rear bushing bore:


Clutch:
Width of assembly:
Number of fibers:
Number of steels:
Main washer type:
Push rod length:
Lifter style:


Transmission:
Sprocket splines:
Bearing at sprocket:
Engagement teeth:
Ratio 1st:
Ratio 2nd:
Ratio 3rd:
Ratio 4th:
Ratio 5th:
MS 1 tooth count:
MS 2 tooth count:
MS 3 tooth count:
MS 4 tooth count:
MS 5 tooth count:
CS 1 tooth count:
CS 2 tooth count:
CS 3 tooth count:
CS 4 tooth count:
CS 5 tooth count:
Bore of 2nd gear:

[Roostius_Maximus]

1988

Head:
Casting:
Chamber depth:
Plug reach:
Squish band width:
Gasket thickness:
Gasket cc:
Chamber cc:


Cylinder:
Exhaust Port:
Opens in crank degrees:
Opens in piston position:
Duration:

Intake Transfers:
Opens in crank degrees:
Opens in piston position:
Duration:

Boost Port Opens:

Plenum Length (gasket surface to piston skirt):


Ignition:
Flywheel weight:
Flywheel Diameter:
Pickup trigger length:
Pickup trigger degrees:
Stator lock plate degrees:

Timing map:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:


Connecting Rod:
Length overall:
Centre to centre:
Housing bore rotating (big end):
Housing bore reciprocating (small end):
Weight rotating end:
Weight reciprocating end:
Total weight:
Crank pin weight:
Crank bearing weight:
Thrust washer weight:
Wrist pin bearing weight:
Wrist pin weight:


Crankcase:
Cylinder sleeve recess Diameter:
Deck height (crank centre to gasket surface):
Right Case style:
Rear bushing bore:


Clutch:
Width of assembly:
Number of fibers:
Number of steels:
Main washer type:
Push rod length:
Lifter style:


Transmission:
Sprocket splines:
Bearing at sprocket:
Engagement teeth:
Ratio 1st:
Ratio 2nd:
Ratio 3rd:
Ratio 4th:
Ratio 5th:
MS 1 tooth count:
MS 2 tooth count:
MS 3 tooth count:
MS 4 tooth count:
MS 5 tooth count:
CS 1 tooth count:
CS 2 tooth count:
CS 3 tooth count:
CS 4 tooth count:
CS 5 tooth count:
Bore of 2nd gear:

[Roostius_Maximus]

1989-90

Head:
Casting:
Chamber depth:
Plug reach:
Squish band width:
Gasket thickness:
Gasket cc:
Chamber cc:


Cylinder:
Exhaust Port:
Opens in crank degrees:
Opens in piston position:
Duration:

Intake Transfers:
Opens in crank degrees:
Opens in piston position:
Duration:

Boost Port Opens:

Plenum Length (gasket surface to piston skirt):


Ignition:
Flywheel weight:
Flywheel Diameter:
Pickup trigger length:
Pickup trigger degrees:
Stator lock plate degrees:

Timing map:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:


Connecting Rod:
Length overall:
Centre to centre:
Housing bore rotating (big end):
Housing bore reciprocating (small end):
Weight rotating end:
Weight reciprocating end:
Total weight:
Crank pin weight:
Crank bearing weight:
Thrust washer weight:
Wrist pin bearing weight:
Wrist pin weight:


Crankcase:
Cylinder sleeve recess Diameter:
Deck height (crank centre to gasket surface):
Right Case style:
Rear bushing bore:


Clutch:
Width of assembly:
Number of fibers:
Number of steels:
Main washer type:
Push rod length:
Lifter style:


Transmission:
Sprocket splines:
Bearing at sprocket:
Engagement teeth:
Ratio 1st:
Ratio 2nd:
Ratio 3rd:
Ratio 4th:
Ratio 5th:
MS 1 tooth count:
MS 2 tooth count:
MS 3 tooth count:
MS 4 tooth count:
MS 5 tooth count:
CS 1 tooth count:
CS 2 tooth count:
CS 3 tooth count:
CS 4 tooth count:
CS 5 tooth count:
Bore of 2nd gear:

[Roostius_Maximus]

1991-92

Head:
Casting:
Chamber depth:
Plug reach:
Squish band width:
Gasket thickness:
Gasket cc:
Chamber cc:


Cylinder:
Exhaust Port:
Opens in crank degrees:
Opens in piston position:
Duration:

Intake Transfers:
Opens in crank degrees:
Opens in piston position:
Duration:

Boost Port Opens:

Plenum Length (gasket surface to piston skirt):


Ignition:
Flywheel weight:
Flywheel Diameter:
Pickup trigger length:
Pickup trigger degrees:
Stator lock plate degrees:

Timing map:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:


Connecting Rod:
Length overall:
Centre to centre:
Housing bore rotating (big end):
Housing bore reciprocating (small end):
Weight rotating end:
Weight reciprocating end:
Total weight:
Crank pin weight:
Crank bearing weight:
Thrust washer weight:
Wrist pin bearing weight:
Wrist pin weight:


Crankcase:
Cylinder sleeve recess Diameter:
Deck height (crank centre to gasket surface):
Right Case style:
Rear bushing bore:


Clutch:
Width of assembly:
Number of fibers:
Number of steels:
Main washer type:
Push rod length:
Lifter style:


Transmission:
Sprocket splines:
Bearing at sprocket:
Engagement teeth:
Ratio 1st:
Ratio 2nd:
Ratio 3rd:
Ratio 4th:
Ratio 5th:
MS 1 tooth count:
MS 2 tooth count:
MS 3 tooth count:
MS 4 tooth count:
MS 5 tooth count:
CS 1 tooth count:
CS 2 tooth count:
CS 3 tooth count:
CS 4 tooth count:
CS 5 tooth count:
Bore of 2nd gear:

[Roostius_Maximus]

1993-01

Head:
Casting:
Chamber depth:
Plug reach:
Squish band width:
Gasket thickness:
Gasket cc:
Chamber cc:


Cylinder:
Exhaust Port:
Opens in crank degrees:
Opens in piston position:
Duration:

Intake Transfers:
Opens in crank degrees:
Opens in piston position:
Duration:

Boost Port Opens:

Plenum Length (gasket surface to piston skirt):


Ignition:
Flywheel weight:
Flywheel Diameter:
Pickup trigger length:
Pickup trigger degrees:
Stator lock plate degrees:

Timing map:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:
rpm: Degrees:


Connecting Rod:
Length overall:
Centre to centre:
Housing bore rotating (big end):
Housing bore reciprocating (small end):
Weight rotating end:
Weight reciprocating end:
Total weight:
Crank pin weight:
Crank bearing weight:
Thrust washer weight:
Wrist pin bearing weight:
Wrist pin weight:


Crankcase:
Cylinder sleeve recess Diameter:
Deck height (crank centre to gasket surface):
Right Case style:
Rear bushing bore:


Clutch:
Width of assembly:
Number of fibers:
Number of steels:
Main washer type:
Push rod length:
Lifter style:


Transmission:
Sprocket splines:
Bearing at sprocket:
Engagement teeth:
Ratio 1st:
Ratio 2nd:
Ratio 3rd:
Ratio 4th:
Ratio 5th:
MS 1 tooth count:
MS 2 tooth count:
MS 3 tooth count:
MS 4 tooth count:
MS 5 tooth count:
CS 1 tooth count:
CS 2 tooth count:
CS 3 tooth count:
CS 4 tooth count:
CS 5 tooth count:
Bore of 2nd gear: