Mercury peeing steam at higher rpms.

wgant

Cadet
Joined
Aug 6, 2010
Messages
8
I just got a 20 hp mercury that i believe is a 1996 that i am trying to fix up. I just installed a brand new water pump kit. When idling and driving up to about high power it is peeing out water decently. when going above that and wot it starts peeing steam. Anybody got any ideas of what this might be? thanks
 

latin monkey

Petty Officer 1st Class
Joined
Jun 5, 2010
Messages
272
Re: Mercury peeing steam at higher rpms.

exhaust cover gaskets are probably bad
 

latin monkey

Petty Officer 1st Class
Joined
Jun 5, 2010
Messages
272
Re: Mercury peeing steam at higher rpms.

how does the motor run/idle? your carbs may be running lean causing the motor to heat up. if you haven't already, clean the carbs and adjust the mixtures
 

wgant

Cadet
Joined
Aug 6, 2010
Messages
8
Re: Mercury peeing steam at higher rpms.

It idles decently. It will die every once and a while while idling. I cleaned the carb once but will probably clean it again.
 

latin monkey

Petty Officer 1st Class
Joined
Jun 5, 2010
Messages
272
Re: Mercury peeing steam at higher rpms.

you can try adjusting the mixture on it while you have it running in forward gear. turn mixture screw 1 1/2 out from seated position before you start, then when you have it warmed up and moving in forward gear turn screw out until it sounds like its missing and running crappy, then turn screw back in just enough until it runs and sounds better. get up to speed and see if it is still steaming. if it is, pull off exhaust cover and check it for cracks or holes. replace gaskets and reinstall. i had one myself where the exhaust cover had about a 1 1/2 inch crack in it
 

wgant

Cadet
Joined
Aug 6, 2010
Messages
8
Re: Mercury peeing steam at higher rpms.

thanks for the help! I got new gaskets on the way and ill try the carb mixture and see how it goes.
 
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