mercury 140hp 2004

[snappernz]

ive got a mercury 140 hp 2004 aniversary model carbureted.im haviong trouble with it overheating at mid revs .
any speed between 8- 20 knots needle goes right accross the gauge ,has had impeller done ,new thermostats 120degs
new poppet valve new temp sender and gauge ,alarm never goes off until last subday it went off in about 500 mtrs, mechanic
is coming out later in the week with a temp gun so we know exactly what the temp is when its reading hot on the gauge .

does anyone have any ideas what else i can check or test . cheers mike

 

[carholme]

Re: mercury 140hp 2004

snappernz;

Interesting that your engine has 120 degree thermostats as the American built engines appear to all have 143 degree thermos. Is your engine an Australian build?

Gerry

 

[quicktach]

Re: mercury 140hp 2004

Is water coming out the pee hole ? You could be running too lean - driving temperatures up. Anyone been doing carb work? Water intake screen clogged ?

 

[snappernz]

Re: mercury 140hp 2004

hi it was recomended by my mechanic to swap 143 deg thermos to 120 to try and fix the prob.theres water coming out the pisser at a good stream. when the motor gets hot all i have to do is drop back to an idle or get the revs back up above 3000 or higher and the temp drops back again, was thinkin could this be a salt buildup or a blown head gasket ,theres no missing motor starts first time from hot or cold

any suggestions would be a great help .cheers mike