S&S Cycle Standard and Easy Start Chain Drive Camshafts for 2006 Harley-Davidson Dyna models and all 2007-up Big Twins User Manual

Page 3

Overview of Easy Start camshafts (if equipped):

S&S® has developed Easy Start Cams to assist starting with a

centrifugally operated compression release. The operation is simple:

at cranking speeds a spring loaded decompression lever holds the

exhaust valve open slightly. Once the engine fires and exceeds 750

RPM, centrifugal force takes over and sends the lever to a retracted

position, allowing the engine to run normally.

Important Notes Regarding Easy Start Camshafts:

• Stock EFI engines require a minimum of 80 PSI cranking

compression, checked with the throttle open, for the ECU to fire the

spark plugs.

• S&S easy start cams were designed to work with specific

compression ratio and displacement combinations. If an Easy Start

cam set is used in an application other than what it was designed

for occasionally an engine may not build the required compression

to start the bike.

• Cranking compression numbers are no longer a valid health check

of the engine. We recommend performing a leak down test.

• If the lifters have been disassembled or bled down for any purpose,

the starter may have difficulty with the initial start. Although the

decompression lobe lifts the lifter body, the lifter is not pumped up

and it will not lift the exhaust valve. You may need to remove the

spark plugs and crank the engine to get oil pressure to the lifters.

• Easy Start cams require no special service. If they are ever removed

for any reason however, inspect the mechanism for wear and verify

that the lever operates smoothly.

• When the engine is turned off, you may hear a slight click as the

decompression lever resets. This is normal and does no harm.

• If engine speed drops below 900 RPM, you may hear clicking as

the decompression lever starts engaging. Idle speed should be

adjusted higher. The engine idle should be set at 1000-1100 RPM.

Securing the motorcycle

Motorcycle must be adequately secured during the cam change
operation! Use of tie down straps on both sides of the motorcycle
is recommended.

1. Place motorcycle on a suitable repair stand so that the

motorcycle is stable and secure with the rear tire elevated.

2. Disconnect the negative terminal of the battery to eliminate

potential sparks and inadvertent engagement of the starter

while working on the motorcycle.

3. Place motorcycle in top gear. Remove spark plugs. These

steps are necessary so that the rear tire can be used to rotate

the engine to correctly align the cam timing marks during

installation, and align the oil pump during reassembly.

Disassembly

Cutting the pushrods with a saw may result in metal chips
entering the engine and causing extensive damage which will
not be covered under warranty.

Cutting pushrods without relieving valve spring force on the
pushrods may result in injury.

Easy Start Chain Drive Cams

Picture 1

Crankshaft/Camshaft Sprocket Locking Tool,

H-D® Part Number: 47941

Camshaft Needle Bearing Remover/Installer,

H-D Part Number: 42325

• All reference to Harley-Davidson part numbers

is for identification purposes only. We in no way

are implying that any of S&S Cycle’s products

are original equipment parts or that they

are equivalent to the corresponding Harley-

Davidson part numbers.

CAUTION

Cam

Intended Displacement Intended Compression Ratio

551

88–106

9.0–10.0

557

96-103

9.6-10.0

570

88–106

9.0–10.0

583

88–106

9.0–10.0

585

88–106

9.2–10.5

625

95+

10.0–10.75

635

106-124

10.2-10.8

640

95+

10.5–11.5

675

120+

11+

HP103

103

9.6-10.0

MR103

103

9.6-10.0