what is good compression on this motor what is bad it idles rough.
P pikefisherman Petty Officer 1st Class Joined Aug 8, 2010 Messages 324 Aug 9, 2010 #1 what is good compression on this motor what is bad it idles rough.
JB Honorary Moderator Emeritus Joined Mar 25, 2001 Messages 45,907 Aug 9, 2010 #2 Re: Merc. 9.8 compression question Rope start, right? Good is both cylinders within 10% of each other and over about 65-70psi. Bad is big difference in psi or both down around 40-50psi.
Re: Merc. 9.8 compression question Rope start, right? Good is both cylinders within 10% of each other and over about 65-70psi. Bad is big difference in psi or both down around 40-50psi.