Table of Contents

EVO: Engine Mechanicals

The Camshafts (4 of them) are used to operate the intake and exhaust valves by means of the lifters (AKA: tappets), the pushrods and the rocker arms. The #2 Cam is driven by the Pinion Gear. The Pinion Gear is mounted on the Pinion Shaft which is part of the Flywheel Assembly.

#1 Cam - Rotates CW – Operates Rear Exhaust Valve
#2 Cam - Rotates CCW - Operates Rear Intake Valve - Driven by Pinion Gear
#3 Cam - Rotates CW – Operates Front Intake Valve
#4 Cam - Rotates CCW - Operates Front Exhaust Valve

Camshafts

The cams get oiled by drainage from the rocker boxes and splash oil in the bottom end.
Oil flows off the pushrod side of the rocker boxes through the pushrod covers, into vertical holes in the lifter bores and into the gearcase.
Oil falls on the cam lobes on the way down this hole. Some of this oil is transferred between the gear teeth.
The rear intake (#2) cam gets a little oil spray from the right case oil feed galley through the small orifice underneath the open cavity in the case.
That oil is transferred between the teeth of the cams.
Oil flung off the cams lands in the gearcase to be collected into the scavenge (return) side of the oil pump.

1992-up Cam Gear Oiler Hole in the Right Case.
Below are pics of the restricted orifice underneath the oil feed galley in the case that shoots a small stream onto #2 cam.
#2 cam rotates counterclockwise and the oil is sprayed on the right side of the cam gear for extra cooling (transferred to all cams).

(L) 92-99 1), (R) 2000 Up 2) cam oiling hole from the feed galley

Cam Specs - OEM & SE

400

IntakeExhaust
Cam GrindLiftOpensClosesDurationLiftOpensClosesDurationOverlap
T 3).278“1°ATDC42° ABDC221°.250”40° BBDC18° ATDC238°17°
C 4).278“1°ATDC42° ABDC225°.280”42° BBDC3° ATDC225°

Comparing OEM and Andrews Cam Grinds

These figures are from the Sportster Evolution Cams PDF from Andrews Products. 5)

GrindI/ETiming
@ .053“ Lift
CLDuration @
.053” Lift
Durarion @
.020“ Lift
Max LiftTDC Lift
WI10°/28°99°218°256°.474”.122“
E38°/16°101°234°272°.474”.138“
N4I30°/46°98°256°296°.490”.216“
E52°/24°104°256°296°.490”.189“

I/E = Intake/Exhaust — CL = Centerline


Thanks to Maxeffort of the XLForum for the following Flywheel Degree Charts of these various cams.6)

The measurements are based on the .053 lift specs. Also, take note that the predominance of the intake valve opening occurs on one rotation of the flywheel and the predominance of the exhaust valve opening occurs on the next rotation of the flywheel. It takes two full rotations (720°) of the flywheel to complete the four-cycle process. (This view of the flywheel would be from the right side of the engine.)






Removing / Installing Evo Cams

Sub Documents

EVO Cam and Pinion Gear Sets

Year Models & Included Parts Cam
Grind
ID
Letter
Cam #1 Cam #2
Outer
Big
Gear
Cam #2
Inner
Small
Gear
Cam #3Cam #4Pinion
Gear
(Drives
Cam #2)
86-87 8)(25488-86) All
cams, pinion gear and cover
T28T36T28T28T28T18T
88-90 9)(25488-88) All
cams, pinion gear and cover
C
91-94 10)(25488-89) All
cams, pinion gear and cover
D
95-97 11)(25488-89A) All except '96 & '97 1200C
cams, pinion gear and cover
D
96-97 12)(25483-96) 1200C
cams, pinion gear and chrome cover
D
98-99 13)(25448-89B) Std/Hug/1200
cams, pinion gear and polished cover
D
(25483-96A) 1200C
cams, pinion gear and chrome cover
D
(25491-98) 1200S
cams, pinion gear and silver cover
W
00 14)(25193-00) all except 1200S
cams and pinion gear (no cover)
D28T46T28T28T28T23T
(25190-00) all except 1200S
Only #2 cam and pinion gear
D
(25194-00) 1200S
cams and pinion gear (no cover)
W
(25191-00) 1200S
Only #2 cam and pinion gear
W
01-03 15)(25193-00A) all except 1200S
cams and pinion gear
D35T46T35T35T35T23T
(25194-00A) 1200S
cams and pinion gear
W
04-06 16)(25193-00B) 883/883C
cams and pinion gear
D
(25194-00B) 1200C/1200R
cams and pinion gear
W
07-17 17)(25194-06) all except XR1200/XR1200X
cams and pinion gear
W
09-12 18)(25271-08) XR1200/XR1200X
cams and pinion gear
?

Cam Gear Changes

20) 21)

Cam Bushings

Inner Bushings

2010 1200X Inner Cam Bushings (broken teeth on oil pump gear) 24) 2010 1200X Cam Cover and Bushings 25)

Outer Bushings

These bushings are fed from splash oil into channeled holes drilled behind the bushing faces.
#1, #3 and #4 cam bores have channels drilled from the top down into the back side of the bores.
The channel for #2 cam bore starts at the bottom and is drilled into the back side of the bore.
The pinion bushing (as well as the hole in the pinion shaft) is fed from a cross drilled hole in the top of the cover.

Lifters (tappets)

Sub-Documents

See also in the Sportsterpedia;

………. Hydraulic Lifter - Disassembly / Inspection / Assembly


The stock Evo Sportster tappets (lifters) are hydraulic as opposed to being solid.
That is, they use oil to fill an internal cavity to create a stiff lifter to press upwards on the pushrod.
This oil-based operation allows the hydraulic lifters to self-adjust for minor changes in valve operation caused by heat expansion.
It eliminates the need for adjustable pushrods. A hydraulic lifter self-adjusts within a certain range. 26)
In other words, if your pushrods are too long, the lifter automatically shortens, and if the pushrods are too short, it automatically lengthens.

The stock tappets are roller lifters as opposed to flat lifters.
There is a rolling wheel at the bottom of the lifter that rides on the cam lobe. \
There are opposing flat spots near the top of the lifter.
To keep the lifter's roller wheel aligned to the cam lobe, there are anti-rotation pins in place nearly up against those flat spots on the lifter.

Stock lifters can be inserted either way, so long as the roller wheel is aligned with the cam lobe and the flats are aligned with the anti-rotation pins afterwards.

1986-up Sportsters were fitted with hydraulic roller lifters (roller tappets) from the factory.
Parts below are for the updated versions from 1986-on.

The drawing below is of a 1991-1999 Sportster OEM lifter and shows the parts mentioned above. However, 2000-up Sportster lifters have the same parts.

27)

Checking Lifter Pre-load

Hydraulic lifters self-adjust over about a .100” range, from .050“ preloaded to .150” preloaded. 28)
They'll actually work outside that range but they might make noise, so it's best to stay in that range.

The lifter plunger should be preloaded between .050 and .150. Make the measurement if you're not sure.
30)

Oil feed to lifters

91 and up engines have a horizontal passage on the top of the cam box that is fed oil from the filter pad.
This horizontal passage feeds into the lifter bores.
Oil is fed internally to the lifter thru a small hole on the side.
The stock lifters can be inserted either way, so long as the roller wheel is aligned with the cam lobe and the flats are aligned with the anti-rotation pins.

91-99 engines have a single passage in that top
area, the tappets are connected by internal
passages from this small cavity.
On 2000 and up engines, oil travels to each lifter
individually from this cavity. 31)

1986-1990 models

There was a running change in 1986 to new style hydraulic lifters as opposed to the original 1986 versions for Sportsters. 32)
They were the same as those used in 1340cc engines beginning in the 1986 model year. The change was to allow for one component to service the entire product line.
Per HD Service Bulletin M-930A;
Beginning with crankcase #1786 127 043 (883cc) and 1886 127 001 (1100cc), new style hydraulic lifters were installed at the factory.
New style lifters can be identified by the presence of notches in the pushrod socket.
Click here to go to the service bulletin page where you can download the service bulletin.

  1. A piece of wire can no longer be used to drain lifter during installation.
  2. After push rod lengths have been measured and the correct length push rods selected, remove lower rocker boxes.
  3. Rotate engine so both lifters from the cylinder being serviced are on the base circle (lowest position of the cam).
  4. Install push rods and push rod tubes. Install new gaskets under lower rocker box.
    Place lower rocker box assembly (with rocker arms and shafts) in position.
    Place push rods in rocker arm sockets.
  5. Slowly snug all rocker box fasteners in small increments (one turn at a time).
    Use a cross pattern on the four large bolts that fasten the lower rocker box to head.
    This will bleed the lifters. Tighten fasteners to the correct torque. Refer to the 1986 XLH Service Manual for the proper tightening sequence.
    CAUTION, Do not turn the engine over until both push rods can be turned with fingers to avoid damage to push rods or rocker arms.
  6. Repeat Steps 2 through 5 for other cylinder

The oil feed to the lifters comes from the oil pump, through a passage in the cam cover to the feed galley in the top of the right case.
The intake lifters are fed oil from the feed galley hole. Each exhaust lifter is fed from it's corresponding intake lifter bore.

1986-1990 lifter oiling path 33)

34) 35)

91-99 Lifters

1991-1999 engines have AMC-Mopar style lifters (.903“ diameter). 36)

1991-1999 lifters (18526-89A) 37)

The oiling hole for the lifters in 1991-1999 engines is drilled from the inside of the right case out through the lifter bore and into the case oil galley.
All four lifter bores are capped on the inside of the right case. This left a blind hole between each lifter toward the inside of the case.

1991-1999 Lifter oil path from filter. 38) Capped holes for the lifter bores inside the case. 39)
91-99 lifter bore 40)
A look inside the oiling holes in the lifter bore on a 91-99 case. Notice the capped hole toward the case in the third pic. 41)

91-99 Anti-Rotation Pins

Parts:
4 - screws (884)
4 - washers (6099)
2 - pin plates (36804-89)
4 - O-rings (11176)
4 - anti-rotation pins (18532-89)

Torque: 80-110 in. lbs. (9.0-12.4 Nm) 42)

91-99 anti-rotation pin hardware 43)
App. pin dims 44)
App. pin plate dims 45)
Slide the pins in the holes, install the O-rings over the pins. 46)
Then install the plate and torque to 80-110 in lbs. 47)

2000 and Up Lifters

2000 and up have GM/twin cam style lifters (.842” diameter). 48)

Lifter from an 02 XL883 49)

2000 and Up engines:
However, the oil galley was now cut into the right case instead of a rifle drilled hole.
This made it easy to drill oiling holes to the lifters from the outside of the case into the lifter bore.
So there were no lifter oiling holes to cap on the inside of 2000 and up cases.

2000 and Up engine lifter oil path. 50)Inside of case has no capped holes for lifter holes. 51)

00-05 Lifter Ant-Rotation Screws

Parts:
4 - anti-rotation screws (18532)

This is the redesigned version of the anti-roll pins.
Comprised of a single pin for each lifter as before (4 in all).
However, this is a one piece design that is threaded into the case with no holding plate.

Torque: 55-65 in. lbs. (6.2-7.3 Nm) 52)

00-05 anti-rotation screws 53) App dims (photos by Hippysmack))
End of screws run up into the case. 54)

06-Up Anti-Rotation Device

Parts:
2 - Anti Rotation Device blocks (18505-06)
The ARD is a flexible piece of plastic that is designed to flex in operation to allow for an imperfect lifter bore location. 55)
It is designed for lifters that have a flat cut on each side.

These work OK for stock cams.
But if you're upgrading to bigger cams, anything more than .600 lift has too small a base circle. 56)
(and they will nearly drop out of the ARDs and they can also spin away from them)
The big issue is that they turn sideways with the roller not turning on the cam lobe.
(which can heat up and destroy the roller and the cam lobe)

ARD block 57) ARD block installed 58)

Pinion Gear

Compatibility 60)
1986-2003 parts books do not list a part number for the pinion gear and it appears the pinion gear is part of the cam gear set (not sold separately).
However, a gear could be ordered from the MoCo. The part# coincides with the color scheme coding on the respective cam sets.
2000-up pinion gear part number is (24047-00) as appearing in the 2004-up parts catalogs.
1986–1987 pinion gears have a (6-spline) pinion shaft.
1988-up pinion gears have no splines and have a notch out the back side (not under) to slide around a woodruff key on the non-splined pinion shaft.
1986-1999 pinion gears have the same coarse (13) tooth pitch.
2000-up pinion gears have a fine (23) tooth pitch.

XL Pinion Gear Color/Size Info here: http://xlforum.net/forums/showthread.php?t=1963918

Part numbers and color coding:
1986-1999 cams continued the color coding as in previous years for optimum noise reduction in the gear mesh.
However, from 1986-1990, there were even more color combinations including cam drive gear sizes.
Each factory pinion gear was colored coded with a dot (even though it was more like a splotch at times) that matched the same colors on the matching cam drive gear.
1986-1990 cam drive gears came with either one dot or two dots. Their corresponding pinion gear also came with one or two dots respectively to that gear set.
1991-1999 cam drive gears were only colored with one dot and likewise, there will only be one dot on their respective pinion gear.
2000-Up factory pinion gears have no color codes.

Factory Pinion Gears by Part Number and Color of Dots (★ = 1 Dot, ★★ = 2 Dots)
1986-1987 Sportster 1988-1990 Sportster
Part#BrownBlueRedWhiteGreenYellowBlackPart#BrownBlueRedWhiteGreenYellowBlack
24055-86 24055-88
24056-86 24056-88
24057-86 24057-88
24058-86 24058-88
24059-86 24059-88
24060-86 24060-88
24061-86 24061-88
25737-86 ★★ 25737-88 ★★
25738-86 ★★ 25738-88 ★★
25739-86 ★★ 25739-88 ★★
25740-86 ★★ 25740-88 ★★
25741-86 ★★ 25741-88 ★★
25742-86 ★★ 25742-88 ★★
25743-86 ★★ 25741-88 ★★
Factory Pinion Gears by Part Number and Color of Dots
1991-1999 Sportster 2000-Up Sportsters
Part#BrownBlueRedWhiteGreenYellowBlackPart#24047-00No Color Coding
24055-91
24056-91
24057-91
24058-91
24059-91
24060-91
24061-91


1986-1987 Sportster (18T) Pinion Gear:
Has internal splines.
61) 62) 63)

1988-1990 Sportster (18T) Pinion Gear:
Has a notch cut out of the rear for the woodruff key (T-key) on the pinion shaft and no splines.
64) 65)

1991-1999 Sportster (18T) Pinion Gear:
Has a ring cut around the circumference of it's rear sleeve, a notch cut out of the rear for the woodruff key (T-key) on the pinion shaft and no splines.
The ring around the sleeve may just be to distinguish the 91-99 gear from the 88-90 gear.
66) 67)

2000-Up Sportster (23T) Pinion Gear:
The ring around the rear sleeve was deleted, has a notch cut out of the rear for the woodruff key (T-key) on the pinion shaft, finer gear mesh and no splines.
68) 69)

Possible 91-up Woodruff Key Failure Notice

There is a bronze oil pump gear available which is considered an upgrade but that won't stop the key from shearing.
Read more about the oil pump drive gear failure and upgrade here in the Sportsterpedia.

The woodruff key on the pinion shaft has been subject to shearing.
Click Here for more information in the Sportsterpedia.

70)

Timing Cup (Rotor)

Timing cup bolt thread size: #10×32
Wrench size: 5/16“
Torque: 43-53 in/lbs 71)
Use Loctite 242 (blue) on the bolt threads 72)
Installing timing cup bolt on a 98 1200S 73)


1)
photo by Hippysmack of the XLFORUM
3) , 4)
MMI Evolution Cam Specs dated 10/5/92
7) , 23)
1986 HD Dealer Sportster FSM pg 3-45
8) , 9)
87-88 HD Sportster Parts Catalog pg 17
10)
91,92,93,94 HD Sportster Parts Catalogs
11)
95 HD Sportster Parts Catalog
12)
95-96 HD Sportster Parts Catalog pg 15
13)
98 HD Sportster Parts Catalog pg 15
14)
00 HD Sportster Parts Catalog pg 17
15)
01 HD Sportster Parts Catalog pg 19
16)
04 HD Sportster Parts Catalog pg 17
17) , 18)
07 HD Sportster Parts Catalog pg 19
27)
drawing by Hippysmack
32)
1986-1990 HD Sportster FSM pg 3-44
34) , 35)
photo by xtremraptor of the XLFORUM
40) , 41) , 43) , 44) , 45) , 46) , 47)
photos by Hippysmack
42)
98 HD Sportster FSM pg 3-5
52)
04 HD Sportster FSM pg 3-7
53)
photo by Hoppysmack
60)
From HD Parts Catalogs 2004 pg 17, 2005 pg 19, 2006 pg 19, 2007 pg 19, 2008 pg 19, 2009 pg 25-27, 2010 pg 25-27, 2011 pg 25-27, 2012 pg 25-27, 2013 pg 29-31, 2014 pg 17, 2015 pg 19, 2016 pg 19
61) , 62) , 64) , 65) , 66) , 67) , 68) , 69)
photo courtesy of c3cycle.com, Link to site:https://www.c3cycle.com/
71) , 72)
1998 XLH FSM pg 7-56
73)
photo by Hippysmack