I have a Force 125 1987. Lost compression on No.2 cylinder so removed cylinder head. Found that the head gasket had gone between pot and water jacket. After inspecting the cylinder head I have noticed pitting around No. 1 & 2 pots. Is it ok to have the head skimmed to remove pitting and how much is a safe amount without causing compression problems?<br />I have checked the water pump impeller and it is not worn at all. Is it ok to rotate the engine by hand the wrong direction or will this cause a problem with the impeller due to the direction to the way the impleller lobes point?<br />I am also wanting to fit a tachometer to my boat. Do I need a special type for my outboard?<br />Any help will be appreciated. 