compression?

[81 clark racing]

can someone tell me what the stock compression should be on a 04 400ex? also should mine be higher or anything do to the mods i have? thanxs steve

[81 clark racing]

stage 2 hot cam, full t4 pipe, jetted uni filter, spark enhancer, curtis sparks adv timeing key

[casey_lamm]

compression 9.1:1 stiock


Originally posted by 81 clark racing
can someone tell me what the stock compression should be on a 04 400ex? also should mine be higher or anything do to the mods i have? thanxs steve

[hornetgod13]

Should be between 100psi to 128psi. Make sure you warm the motor first before you installed the compression tester and hold the throttle wide open when you crank the motor.

[drew416ex]

Originally posted by hornetgod13
Should be between 100psi to 128psi. Make sure you warm the motor first before you installed the compression tester and hold the throttle wide open when you crank the motor.

Stock will read this but since you have a little larger cam it may be a little lower due to more valve overlap.