This is my 1st post. I have been lurking in the forums for years and acquired a lot of info from goggling. so its about time I got into the club!
Everyone claims that the motors are the same in a 425 and the 445 except, a carb on the 425 and EFI on the 445 with a gain of 2 HP. However, I looked at the operator's manual and it states in specifications that the 425 have 9.0 compression and the 445 has 10.3. So can someone explain to me what component(s) (cylinder heads, piston, or ect) offsets the compression difference between the two engines?
Also; what should a compression gauge show for good compression for the two engines?
Thank you in advance.